1. Vaphiades MS, Newman NJ. Optic nerve enhancement on orbital magnetic resonance imaging in Leber's hereditary optic neuropathy. J Neuroophthalmol 1999; 19:238-9.
Riordan-Eva P, Sanders MD, Govan GG, et al. The clinical features of Leber's heredity optic neuropathy defined by the presence of a pathogenic mitochondrial DNA mutation. Brain 1995; 118:319-37.
Guy J, Mancuso A, Quisling RG, et al. Gadolinium-DPTA-enhanced magnetic resonance imaging in optic neuropathies. Ophthalmology 1990; 97:592-600.
Optic Nerve Head Drusen and Ischemic Optic Neuropathy
First Author:
Andrew Lee, MD, Iowa City, Iowa
Background:
Ischemic optic neuropathy is a well recognized but rare association with optic nerve head drusen.
Methods:
Retrospective case series of all cases of ischemic optic neuropathy due associated with optic nerve drusen from two academic tertiary care centers.
Results:
15 cases of ischemic optic neuropathy in patients with optic nerve head drusen are reported. Younger age and lack of typical associated vasculopathic risk factors were present in these cases when compared with typical non-arteritic ischemic optic neuropathy.
Conclusion:
Optic nerve drusen may be a risk factor for the development of ischemic optic neuropathy. Ophthalmoscopic or ultrasound detection of disc drusen in a patient with ischemic optic neuropathy may obviate the need for more extensive evaluation for ischemic optic neuropathy in a younger patient or one without vasculopathic risk factors.
Optic Neuritis in Anti-GQ1b Positive Miller Fisher Syndrome
First Author:
Jane Chan, MD, Las Vegas, Nevada
Abstract:
Only three cases of optic nerve involvement in presumed Miller Fisher syndrome (MFS) have been documented in the literature. This report further confirms that optic neuritis may be seen in anti-GQ1b positive MFS. This 23-year old woman presented with acute blurry vision, diplopia, and pain with eye movement. Her visual acuity was 20/20 OD and 20/200 OS with a left APD. Visual fields were normal. She had bilateral sixth nerve palsies, nystagmus in all gazes, and left optic disc edema. After one week her visual acuity improved to 20/20 OU, but her left disc remained edematous. She then developed rapidly progressive gait ataxia and absent deep tendon reflexes in her lower extremities. Her MRI of the brain and entire spine and MR venogram were all normal. Her CSF opening pressure was 150 mm H20 and her CSF protein was elevated at 70 mg/dL. Her VEP revealed a delayed left P100 latency and her BAEP was normal. EMG/NCV study revealed prolonged F-waves. Anti-GQ1b antibodies were positive at high titers. Antibodies for acetylcholine receptor, hepatitis A, B, and C; Lyme, Hu, MaTa, Yo, CV-2, and Ri were all negative. After plasmapheresis she fully recovered two months later. In addition to the classic triad of ophthalmoplegia, ataxia, and areflexia, visual impairment presenting as optic neuritis may be a feature of anti-GQ1b positive MFS. Optic disc edema associated with an ipsilateral delayed P100 latency confirms a pre-chiasmal optic nerve dysfunction in this patient. Anti-GQlb IgG antibodies are present in 80% to 100% of patients with MFS. Since high concentrations of GQ1b gangliosides are known to be present in the human optic nerve, optic neuritis is probably a result of anti-GQ1b IgM complement-mediated inflammatory demyelination. The additional electrophysiological evidence of abnormal prechiasmal dysfunction in this case confirms that an autoimmune optic neuropathy may occur in MFS patients.
Optic Neuritis with Extensive Distension of the Optic Nerve Sheath
First Author:
H. E. Killer, MD, Basel, Switzerland
Background:
Cerebrospinal fluid is postulated to communicate freely between all interconnected cerebrospinal fluid compartments. The subarachnoid space of the optic nerve resembles a cull de sac anatomy and is part of the cerebrospinal fluid system.
Objective:
To report a case of unilateral optic neuritis with extensive distension of the optic nerve sheath due to fluid accumulation in the subarachnoid space.
Methods:
Interventional case report.
Results:
A 38-year-old male patient was admitted because of visual loss in the OD and pain on eye movements. On examination the best visual acuity in the OD measured 20/50 and 20/20 in the OS. 16 out of 18 Ishihara plates were identified with the OD. The papilla in the OD was prominent while the fundus examination of the OS was normal. All laboratory examinations were normal. An MRI of the brain showed no signs of demyelination but massive distension to the right optic nerve sheath with pooling of fluid in the subarachnoid space. The diagnosis of optic neuritis was made and the patient was treated with methylprednisolone. Visual functions in the OD improved over two weeks. An MRI of the orbit was repeated two month later that demonstrated normal diameters of both optic nerve sheaths.
Conclusions:
Optic neuritis can lead to an increase of fluid in the subarachnoid space with a consecutive rise of the local pressure. If there is a lack of communication between the subarachnoid space of the involved optic nerve and the chiasmal cistern, an optic nerve sheath compartment syndrome may result.
Retinal Vasospasm During an Attack of Migraine
First Author:
H. E. Killer, MD, Basel, Switzerland
Background:
Vasospasm plays a major role in the pathogenesis of a number of diseases. Vasospasm can involve blood vessels of different organs, especially the coronaries and the finger arteries. In the brain short spasms occur mostly in the context of migraine. The blood circulation of the eye is often involved the so-called primary vasospastic syndrome and in migraine. The choroid and the vessels of the optic nerve head seem to be affected more often than the retinal vessels.
Methods:
Case report of a patient that suffered from a unilateral visual field defect in the OS during a episode of migraine. Fundus examination of the OS demonstrated disruption of blood flow in the lower temporal artery due to vasospasm.
Conclusions:
Homonymous scotomas due to occipital hypoperfusion are more common than unilateral scotomas due to retinal migraine. Retinal migraine, however, is of special interest, as the postulated hypoperfusion and the vasoconstriction can directly be observed on fundus examination.
The Architecture of the Arachnoid Trabeculae and Septae in the Subarachnoid Space of the Human Optic Nerve: Anatomy and Clinical Considerations
First Author:
H. E. Killer, MD, Basel, Switzerland
Objectives:
To describe the anatomy and the arrangement of the arachnoid trabeculae and septae in the subarachnoid space (SAS) of the human optic nerve and to consider their possible clinical significance for cerebrospinal fluid dynamics and cerebrospinal fluid pressure in the SAS of the optic nerve.
Methods:
Postmortem study carried out in 11 subjects without ocular disease. All optic nerves used in this study were obtained no later than 7 hours after death. The study was performed with light microscopy, transmission electron microscopy, and scanning electron microscopy.
Results:
The subarachnoid space of the human optic nerve contains a variety of trabeculae and septae. There is a great variability concerning density and anatomic structure depending on the location within the different portions of optic nerve. In the bulbar segment (ampulla) adjacent to the ocular globe, a dens and ramified meshwork of delicate trabeculae is arranged in a net like fashion. In the midorbital portion, the subarachnoid space is subdivided and at some locations appears even loosely chambered by broad trabeculae and velum like septae. A similar type of trabeculae as observed in the bulbar segment can be found in the intercanalicular portion of the subarachnoid space.
Conclusions:
The subarachnoid space of the human optic nerve contains a complex system of arachnoid trabeculae and arachnoid septae that divide the subarachnoid space into a multichambered cerebrospinal fluid compartment. Due to the architecture of the trabeculae and septae cerebrospinal fluid dynamics are influenced by their presence.
The trabeculae and septae described in this study are of delicate character such and can not be visualized even with high resolution magnetic resonance imaging (MRI). The results of this post mortem study may contribute to the understanding of the pathophysiology of asymmetric papilledema, unilateral papilledema and probably normal tension glaucoma.
Treatment of Acute Visual Loss in Idiopathic Intracranial Hypertension
First Author:
Mitchell Strominger, MD, Brooklyn, New York
Background:
Idiopathic Intracranial Hypertension (IIH) is a condition of unknown etiology leading to elevated cerebrospinal fluid pressure with papilledema in the absence of hydrocephalus. If the disc swelling is severe, patients can present with significant reduction in visual acuity. The treatment of patients with acute visual loss includes oral carbonic anhydrase inhibitors, repeated lumber puncture, lumbar peritoneal shunts, oral or intravenous corticosteroids, optic nerve sheath fenestration or a combination thereof. In 1994 Liu, Glaser, and Schatz recommended a regimen of methylprednisolone (250mg IV QID × 5 days) in combination with acetazolamide (500 mg BID × 5 days) and ranitidine (150 mg BID × 5 days), followed by prednisone (80 mg per day) tapered over six weeks for the treatment of acute, severe visual loss.
Objective:
This study was to determine whether the members of NANOS followed the above recommendations.
Methods:
We surveyed 242 members of NANOS and asked whether they followed the recommend treatment regimen. We defined severe, acute visual loss as visual acuity worse than 20/30 or visual field defect of grade 3 or worse. If not, we asked them to specify their preferred treatment.
Results:
44 (18%) returned the survey by fax. 30 ophthalmologists, 6 neurologists, 5 with training in both, and 3 did not indicate. 11 (25%) used the recommended treatment regimen. Of the remaining 33 (75%) respondents, many modifications were noted. 10 used higher doses of acetazolamide including 3 who recommended intravenous. Two tapered the prednisone more rapidly. 18 (55%) included optic nerve sheath fenestration or lumbar peritoneal shunting.
Conclusions:
There is no consensus as to the treatment of acute visual loss in IIH. Most physicians used some modification of the recommended regimen with the addition of ONSF or LP Shunting. Further studies are needed to determine the best treatment of this disorder.
The Evaluation of Isolated Third Nerve Palsy Revisited: an Update on the Evolving Role of Magnetic Resonance, Computed Tomography, and Catheter Angiography
First Author:
Andrew Lee, MD, Iowa City, Iowa
Abstract:
The evaluation and management of the neurologically isolated third nerve palsy continues to evolve. The major concern for the clinician confronted with a patient with a third nerve palsy has been the exclusion of an intracranial aneurysm. The evolution of new imaging techniques such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA) have provided new imaging options for clinicians. This paper reviews the pertinent recent literature on the use of these imaging studies in evaluating the patient with a third nerve palsy.
Posterior Ischemic Optic Neuropathy Complicating Laparoscopic Prostatectomy
First Author:
Clifton Otto, MD, Tacoma, Washington
Background:
Posterior ischemic optic neuropathy (PION) is a rare condition that typically occurs intra-operatively from sustained hypotension, anemia, or direct pressure to the globe, resulting in ischemic infarction of the retrobulbar portion of the optic nerve. PION can also be caused by elevated episcleral-venous pressure, as demonstrated by this first case following laparoscopic prostatectomy.
Objective:
To present a case of posterior ischemic optic neuropathy (PION) secondary to laparoscopic prostatectomy.
Methods:
Case report with discussion of findings.
Results:
This 65-year-old male presented with acute onset of loss of vision in the temporal field of the OD after regaining consciousness following a fifteen-hour laparoscopic prostatectomy. The patient received 15 L of crystalloid during this procedure to maintain urine output. Marked swelling of the patient's eyelids, face and upper extremities was noted by anesthesia halfway through the procedure, but there was no prolonged hypotension, significant anemia, or evidence of direct pressure over the eyes reported during surgery. Formal visual fields revealed a temporal scotoma in the OD consistent with the patient's subjective loss of vision, a finding that was not present on previous visual fields obtained for management of glaucoma in the other eye. No optic nerve swelling or retinal hemorrhage was present. Visual fields obtained over the following eight months showed mild progressive improvement in the temporal field of the OD, corresponding with the patient's subjective observation of gradual expansion of his temporal field of vision. Carotid artery duplex and MRI of the brain and orbits were both normal.
Conclusions:
Given the lack of intraoperative hypotension, anemia or direct pressure to the globe in this case, sustained elevation of episcleral venous pressure during surgery is the most plausible cause of this patient's optic neuropathy. Intraoperative findings suggest that measures should be taken to prevent excessive periorbital swelling during prolonged surgery.
The Obvious Is Not So Obvious
First Author:
Adam Cohen, MD, Burlington, Vermont
Objectives:
To describe an unusual presentation of giant cell arteritis; to discuss a plethora of teaching points, and review the medical literature on orbitopathy secondary to giant cell arteritis.
Methods:
Case Report.
Results:
A 67-year-old man presented 12/99 with decreased vision in both eyes, particularly over the prior month. His medical history included biopsy-proven giant cell arteritis (diagnosed 9/99), Type 2 diabetes mellitus, atrial fibrillation necessitating amiodarone (started late 11/99), and alcoholism. Due to concern about the impact of systemic corticosteroids on his diabetes, and avoidance of methotrexate given his long history of alcoholism and probable liver damage, he was started on pulse cyclophosphamide therapy to facilitate the corticosteroid taper. He was admitted to the hospital 12/99 with a 2-week history of progressive right upper and lower extremity edema, generalized weakness, and bilateral visual loss. Bedside neuro-ophthalmologic examination revealed visual acuities of 20/200 OU with bilateral proptosis and tight orbits, lid edema, conjunctival chemosis, mildly elevated optic discs with sectoral right optic disc pallor, and moderate background diabetic retinopathy with minimal macular involvement in both eyes. Computed tomography was remarkable for bilateral proptosis, with normal extraocular muscles, orbital fat, and paranasal sinuses. His Westergren erythrocyte sedimentation rate was 67; having been 22 one-week prior, and C-reactive protein was 4.7. Thyroid function tests were normal. Concurrent with discontinuation of the amiodarone, intravenous methylprednisolone one gram daily was initiated. After further visual decline, bilateral transconjunctival orbital decompression surgery was performed, with bilateral orbital fat biopsies, stains, and cultures, which were unremarkable. Despite decreased proptosis and softer orbits, vision failed to recover in either eye.
Conclusions:
Giant cell arteritis may present in a variety of ways, including bilateral orbital ischemia resembling inflammatory orbital pseudotumor or dysthyroid orbitopathy.
Ocular Bartonellosis Mimicking Ocular Metastases
First Author:
Aki Kawasaki, MD, Lausanne, Switzerland
Background:
Bartonella henselae is the causative agent of cat-scratch disease. In 5-10% of cases, the eye is involved. Two well-known, ocular complications are conjunctivitis and neuroretinitis. Other posterior segment manifestations are increasingly recognized including inflammatory chorioretinal lesions (white spots), serous retinal detachment, vaso-occlusive disease and optic disc granulomas.
Objective:
To report a patient who had multiple mass lesions in one eye (optic disc, macula, peripheral retina) and positive serologies for acute Bartonella henselae infection.
Methods:
Case report.
Results:
A 12-year-old boy developed headache and visual loss in his OS to 20/400 acuity. Funduscopy showed marked optic disc swelling with peripapillary subretinal elevation. A large creamy-colored mass was present in the macula as well as smaller, discoid-shaped elevated lesions in the periphery. An inferior serous retinal detachment was also present. There was no evidence of ocular inflammation. Ultrasound confirmed the presence of a solid mass at the optic disc and at the macula. Workup for possible metastatic disease was negative. Bartonella serologies were initially negative then showed greater than fourfold rise in titers one month later. The patient was treated with doxycycline; the ocular masses disappeared within 4 weeks and vision recovered to 20/70.
Conclusions:
We report the first case of a macular mass presumably due to Bartonella inflammation. The presence of multiple mass-like lesions in the absence of systemic or ocular inflammation was suggestive of ocular metastases. We alert the clinician to yet another clinical presentation of cat-scratch disease.
Orbital Infarction after Intranasal Cocaine
First Author:
Gregory Van Stavern, MD, Detroit, Michigan
Background:
Orbital infarction syndrome is uncommon, and results from ischemia of all intraocular and orbital structures. It has been reported in a variety of settings. Cocaine has potent sympathomimetic and vasoactive properties, and has been associated with retinal vascular occlusions. We describe a case of orbital infarction syndrome associated with intranasal cocaine use.
Objective:
To describe an uncommon syndrome, as well as a previously unreported complication of intranasal cocaine use.
Results:
A 36-year-old woman presented with sudden, painful visual loss O.S., and complete left ophthalmoplegia. The patient has attended a party the previous evening, and consumed alcohol, and intranasal cocaine. She lost consciousness with her left face pressed against a desktop. She awoke with complete blindness in the OS, left orbital pain, left ptosis, left proptosis, and complete left ophthalmoplegia. An urgent MRI, including fat-suppressed orbital views, showed diffuse edema of all left extraocular muscles, but no other abnormalities. MRA/MRV were normal. A cerebral angiogram, performed 48 hours after the patient had awoken, was normal, with questionable delayed choroidal filling. Bedside examination showed VA of 20/20 OD, NLP OS. She had complete left ptosis, mild periorbital edema, and complete left ophthalmoplegia. The left fundus showed diffuse retinal edema. The remainder of her neuro-ophthalmic examination was unremarkable. An extensive inflammatory and hypercoagulable evaluation was unrevealing. She was seen one week later in clinic. The orbital pain was improved. Examination was similar, except for modest improvement in left ductions and left ptosis. The retinal edema had resolved.
Conclusions:
Orbital infarction has been described in patients with prolonged head compression, as well as a variety of inflammatory and hypercoagulable disorders. The combination of left orbital compression and the vasoactive properties of cocaine resulted in orbital infarction syndrome in this patient. This potential complication of intranasal cocaine has not previously been reported.
Unusual Visual Loss in Papilledema Associated with Parapapillary Neovascular Membrane
First Author:
Francois Borruat, MD, Lausanne, Switzerland
Background:
The incidence of visual loss amongst patients with idiopathic intracranial hypertension (IIH) ranges from 10% to 26%. Causes of visual loss include optic atrophy, anterior ischemic optic neuropathy, arterial or venous retinal occlusion, maculopathy, and subretinal neovascular membrane (NVM).
Objective:
To report an unusual case of visual loss secondary to NVM in a patient with otherwise asymptomatic IIH.
Methods:
Case report.
Results:
A previously healthy 39-year-old man presented with left visual loss for 2 weeks. Visual acuity was 20/20 RE and 20/30 LE. Visual field revealed enlarged blind spot and cecocentral scotoma in the OS. Vitreous cells were present in the OS with a slight inflammation in the left anterior chamber. Fundus examination revealed bilateral swollen optic discs with bilateral temporal superior parapapillary subretinal nodules (1.9 and 2.3 mm on B-scan echography) and left partial macular star. Results of lumbar puncture and blood serologies for inflammatory and infectious disorders were twice negative. Vision progressively worsened to 20/100 due to the progression of the left macular star. Bilateral parapapillary NVM were suspected. Intraventricular intracranial pressure was continuously monitored revealing nocturnal sustained peaks of hypertension (max. 40cmH2O during 15-20 minutes, 10-12×/night). Lumbo-peritoneal shunt was performed. Evolution was then favorable with improvement of left visual acuity to 20/30 and spontaneous involution of NVMs.
Conclusions:
Parapapillary NVM is a rare event complicating papilledema, as only 10 cases have been thus far reported in the literature. It is believed to be associated with long-standing papilledema. Indeed half of the reported cases (including the present case) are asymptomatic until visual loss. Successful treatment of IIH is frequently followed by spontaneous involution of the NVM. However, 4/7 cases failed to recover visual acuity. Early recognition and treatment of IIH might improve visual prognosis of patients with associated NVM.
Neuro-Ophthalmic Manifestations of Patients with Unruptured Intracranial Aneurysms
First Author:
M. Tariq Bhatti, MD, Gainesville, Florida
Objective:
To determine the frequency of neuro-ophthalmic findings in patients with unruptured intracranial aneurysms and to correlate patient characteristics and outcome with these findings.
Methods:
A retrospective chart review of 186 consecutive patients with unruptured intracranial aneurysms operated at the University of Florida by a single surgeon (ALD) between 1989 and 1994. Analysis was performed on the clinical characteristics of patients with only preoperative or postoperative ophthalmic findings. Preoperative presenting ophthalmic findings were analyzed to determine their resolution, improvement, stability, or worsening at final follow-up. Ophthalmic outcomes were correlated with patient age, duration of symptoms prior to surgery as well as size of the aneurysm(s).
Results:
Sixty-three (34%) of 186 patients with unruptured intracranial aneurysms had ophthalmic signs or symptoms. Fifty six (89%) were females and 7 (11%) were males. Fifty-seven (89%) were Caucasians. Age ranged from 18 to 75 years (mean age 53 years + SD). The most common aneurysm location was the ophthalmic artery (33%) followed by the posterior communicating artery (23%). In 62% (39/63) of patients, the ophthalmic findings were the presenting manifestation of the aneurysm. The presenting manifestations in descending order of frequency were diplopia (23%), decreased vision (17%), headache (15%), visual field defects (14%) and retro-orbital pain (6.3%). Shorter duration time of symptoms prior to surgery was not associated with an increased incidence of postoperative ophthalmic improvement (< 1 month, 45% versus > 1 month, 60%). There was a statistically significant correlation between younger age and improved outcome of the presenting sign or symptom. Furthermore, improved outcome was more likely to occur in patients with small (1-14 mm) aneurysms. Large (15-24 mm) and giant (>25 mm) aneurysms were associated with an almost equal chance of improved or worsened symptoms. Forty-one percent (26/63) of patients had multiple aneurysms. Postoperatively, forty-one percent (26/63) of patients developed ophthalmic findings that were not present before surgery. Of these new findings, ptosis and anisocoria were more likely to improve when compared with ocular motility disturbances.
Conclusions:
Neuro-ophthalmic manifestations are common in patients with unruptured intracranial aneurysms and can often be the presenting feature. The outcome of ophthalmic findings seems to be related to age of patient and size of the aneurysm. Early surgery was not associated with a greater likelihood of improved ophthalmic outcome. A large proportion of patients with ophthalmic findings have multiple aneurysms, some of which may be remote from the visual and ocular motility pathways.
Spatiotemporal Profile of Cortical Responses to Visual Motion Stimuli Analyzed by MEG
First Author:
Satoshi Kashii, MD, Kyoto, Japan
Objective:
To elucidate the spatiotemporal activity of a cortical network for processing the motion perception, a magnetic encephalographic (MEG) study was performed in six healthy right-handed subjects.
Methods:
A random dot kinematogram was used for the visual stimuli. It consists of 320 white square dots randomly projected on a screen against a global dark background. The subjects were instructed to look at the fixation point at the center of the screen with both eyes. Each dot moved smoothly at a constant speed. Coherent movement of 390 milliseconds duration and random movement of 1320 milliseconds were presented alternately. During the coherent period, a certain proportion of the total dots (i.e. 50, 70 and 100%) moved in a uniform direction, whereas the rest of the dots moved in random but constant directions. The magnetic responses were recorded in a magnetically shielded room using a 122-channel whole-head magnetometer.
Results:
Two components of magnetic fields were observed in the bilateral temporal and occipital areas in all subjects, with right temporal dominance. We focused on the first component in the right temporal area as they had large amplitudes and were readily distinguished. As the coherence levels rose, the peak latencies of the first component shortened markedly. The mean latencies (± SD ) for the coherence level of 100, 70 and 50% were 233 ± 21.6, 250 ± 22.5 and 278 ± 35.4 milliseconds, respectively. Estimated sources of the first components in all subjects were consistently identified in the right lateral occipitotemporal cortex, the human MT/V5. As the coherence level increased from 50, 70 to 100%, the dipole strength increased from 3.8 ± 3.1, 5.0 ± 3.9, to 8.3 ± 6.9 nAm, respectively.
Conclusions:
These results suggest that the coherence level of dot motion stimulus is reflected in the net activation of hMT/V5.
The Effect of Optic Disk Edema on Spontaneous Venous Pulsations in the Absence of Elevated Intracranial Pressure
First Author:
Timothy McCulley, MD, Cincinnati, Ohio
Background:
Although often considered a sign of elevated intracranial pressure, alternative factors may influence the loss of spontaneous venous pulsations of the optic disk.
Objective:
To evaluate the effect of optic disk edema on spontaneous venous pulsations in the absence of elevated intracranial pressure.
Methods:
Twenty consecutive patients with unilateral optic disk edema due to anterior ischemic optic neuropathy (n = 11) or optic neuritis (n = 9) and a normal contralateral optic nerve were evaluated for the presence of spontaneous pulsations of the superficial veins of the optic nerve head in both eyes. The proportion of subjects with spontaneous venous pulsations present in both eyes, in the involved eye only, in the uninvolved eye only, and in neither eye was determined. Exact McNemar's test was used to evaluate an effect of optic disk edema on the presence of spontaneous venous pulsations.
Results:
Spontaneous venous pulsations were observed in 60% (12/20) of uninvolved eyes and 5% (1/20) of eyes with optic disk edema. This difference was statistically different (p < 0.005). Venous pulsations were absent in both eyes of seven subjects, and present only in the uninvolved eye of twelve patients. No subject had venous pulsations present in both eyes. One patient with ischemic optic neuropathy and segmental optic disk edema had a venous pulsation present on the non-edematous half of the nerve.
Conclusions:
Optic nerve head edema may cause the cessation of spontaneous venous pulsations in the absence of elevated intracranial pressure.
Isolated Neurogenic Blepharoptosis Secondary to Traumatic Eyelid Injury
First Author:
Timothy McCulley, MD, Cincinnati, Ohio
Background:
Isolated neurogenic blepharoptosis is rare and when encountered usually due to compression of the oculomotor nerve.
Objective:
To describe a series of patients with isolated neurogenic ptosis secondary to traumatic eyelid injury.
Methods:
Case series.
Results:
Three previously healthy patients (2 males, 1 female; ages 29, 37, and 39) were evaluated for blepharoptosis following eyelid trauma. All three injuries involved forceful anterior displacement of the involved upper eyelid by a finger placed under the eyelid. Two occurred during domestic altercations and one while the patient was playing basketball. All patients were evaluated within 48 hours of injury and found to have complete ptosis with no levator function, consistent with loss of innervation to the levator palpebrae superioris muscle. Additional findings included minimal eyelid ecchymosis and edema in all cases and subconjunctival hemorrhage in two cases. All patients had full ocular motility and were orthophoric in all fields of gaze with no anisocoria. The remainder of the examinations of the involved and contralateral eyes was unremarkable with visual acuities correctable to 20/20. All cases were managed conservatively with observation only, and within two weeks all three patients had recovered completely with normal symmetric lid height and levator function.
Conclusions:
Ptosis secondary to isolated injury to the oculomotor nerve branch to levator palpebrae superioris may result from traumatic anterior displacement of the upper eyelid. Complete resolution is likely within two weeks.
Surgical Treatment of Skew Deviation
First Author:
Robert Sanke, MD, Oklahoma City, Oklahoma
Background:
Skew deviation is a supranuclear vertical ocular misalignment, which may cause comitant or noncomitant hypertropia. Alternating hypertropia on lateral gaze is a common pattern, and the incomitance of this condition makes strabismus surgery challenging.
Objective:
To evaluate results of strabismus surgery for skew deviation.
Methods:
A retrospective chart review of patients with skew deviation seen from January 1992 until November 2001 was undertaken. Ten patients who underwent strabismus surgery for skew deviation were identified. Successful outcome was defined as 2 prism diopters or less of vertical deviation in the primary position, coupled with patient satisfaction on subjective questioning.
Results:
The most common cause of skew deviation was stroke, which was seen in 6 patients. Eight of the 10 patients were successfully treated, 6 with one surgical procedure and 2 with two procedures. Patients with alternating hypertropia (bilateral inferior rectus skew pattern) were treated with bilateral inferior rectus resection, and in one case with subsequent bilateral superior rectus recession. Patients with non-alternating or comitant hypertropias were treated with either ipsilateral inferior rectus resection or contralateral inferior rectus recession. One case of skew occurred with a comitant exotropia and was successfully treated with vertical transposition of the horizontal rectus muscles. The two patients who failed surgical management were treated with a combination of oblique weakening procedures coupled with vertical rectus surgery.
Conclusions:
Skew deviation can be amenable to strabismus surgery. For alternating hyperopia, bilateral inferior rectus resection is our treatment of choice and may be coupled with superior rectus recession when needed. Non-alternating or comitant vertical deviations are well managed with conventional vertical rectus muscle surgery, but vertical transposition of the horizontal recti may be useful when there is an accompanying large horizontal deviation. Oblique muscle surgery is ineffective and not recommended for this condition.
Should Phenylephrine Be Used as a Topical Mydriatic Agent in Ischemic Optic Neuropathy?
First Author:
Misha Pless, MD, Pittsburgh, Pennsylvania
Objective:
To report 4 patients with the diagnosis of non-arteritic ischemic optic neuropathy (NA-ION) who experienced acute worsening of visual function after instillation of phenylephrine for dilated funduscopic examination.
Methods:
A retrospective chart review of 125 patients treated in the Neuro-ophthalmology unit of the University of Pittsburgh's Eye and Ear Institute between 1996 and 2001 with the diagnosis of NA-ION.
Results:
Between 1996 and 2001, 4 patients (age range 54-82, 1F 3M) were identified who experienced acute worsening of visual function immediately or shortly after administration of topical mydriatic agents given for funduscopic visualization and diagnostic purposes. In all cases one drop each of 2.5% phenylephrine and 0.5-1% tropicamide was used. Three patients had classic risk factors such as hypertension, diabetes, and had a contralateral disc at risk. The female and youngest patient had ION presumed secondary to Lupus. The range of time from acute visual loss to presentation to neuro-ophthalmic care ranged from 1-6 days. The time of onset of the decline in visual function ranged from 45 minutes (patient with lupus) to 12 hours after instillation of mydriatic drops. Visual acuity at diagnosis ranged from 20/40-20/400.
Conclusions:
Phenylephrine is a mydriatic which has vasoconstrictive properties and which may be absorbed by the cornea, thus yielding non-negligible intraocular concentrations. Vasoconstriction of the watershed posterior ciliary capillary beds may occur as a result. This may cause further infarction of already compromised circulatory territories in edematous optic nerves. Because phenylephrine is a known vasoconstrictor in vivo and in vitro it is potentially more likely to cause deleterious vasoconstriction and an acute decline in visual function in patients with acute ION, than tropicamide. After reviewing these data I have modified my practice so phenylephrine is no longer used to dilate pupils of patients with ION or retinal artery occlusion.
Möbius Syndrome Plus
First Author:
Jacqueline Leavitt, MD, Rochester, Minnesota
Objective:
To report a patient with Möbius-like syndrome with intact lateral rectus function and multisystem abnormalities including: hypogonadism, short stature, peripheral neuropathy, mental retardation, hearing loss, and anosmia.
Methods:
Case report and literature review.
Results:
23-year-old woman admitted for GI pain. History of intrauterine growth retardation. She has short stature, hypogonadism, hearing loss, anosmia, mental retardation, and progressive sensorimotor peripheral neuropathy. Family history was negative for ptosis or any EOM problems. Since childhood she has had facial diplegia and ophthalmoparesis. She has incomplete asymmetric ptosis, large angle exotropia, intact lateral gaze but marked deficit of infraduction, supraduction and adduction OU. Dolls head maneuver was negative. Pupils were 3mm and nonreactive. MRI: Asymmetric skull, colpocephaly, atrophic corpus callosum, small cerebral peduncles and periatrial white matter atrophy. Workup for mitochondrial cytopathy was negative.
Conclusions:
Möbius originally described facial diplegia and bilateral abducens palsy. Subsequently cases in the literature have been called Möbius syndrome that have facial diplegia associated with a host of other cranial nerve palsies. This case may represent a separate entity from Möbius syndrome and has more extensive systemic and cranial nerve involvement then previously described cases of Möbius and hypogonadism and neuropathy.
Photophobia in Patients with Pseudotumor Cerebri
First Author:
Deborah Friedman, MD, Syracuse, New York
Objective:
To determine the prevalence of photophobia at the time of diagnosis of Pseudotumor Cerebri (PTC).
Methods:
Neuro-ophthalmic medical records of 180 patients with a diagnosis code of PTC or papilledema from 1991 to 2000 were obtained. Eighty-two patients met predetermined criteria for the diagnosis of PTC. These records were systematically reviewed (DIF) to determine if photophobia was reported by patients at their initial presentation of PTC.
Results:
Five patients (6%) indicated photophobia during their first interview, which was often severe.
Conclusions:
Our retrospective review indicates that photophobia as one of the presenting symptoms of PTC is uncommon but, when present, can be quite dramatic. Review of the literature indicates that it is rarely reported. It is unclear whether the photophobia in PTC is etiologically related to other central causes of photophobia.
Adjuvant therapy for invasive sino-orbital fungal infection
First Author:
Roger Turbin, MD, Newark, New Jersey
Background:
The treatment of invasive sino-orbital fungal infection is complicated both by the presence of comorbid medical conditions, and the resulting disfigurement of radical surgical debridement. Both of these factors limit therapeutic options. Aggressive surgical debridement, often including extensive sinus surgery supplemented by exenteration and administration of systemic antifungals, is common. Despite aggressive surgical and medical intervention, however, these infections typically result in a prolonged disease course with high morbidity and mortality.
Objective:
To report the authors' experience in the management of invasive sino-orbital fungal infection treated with retrobulbar injection and surgical or postoperative irrigation of amphotericin B (AmphB) as an adjuvant to systemic antifungal therapy, and limited, conservative, biopsy or debridement procedures.
Methods:
Retrospective chart review of a consecutive case series. Data concerning comorbid conditions, vision, motility and orbital examination, radiographic findings, and clinical outcome are provided. Fungal species, treatment data, and surgical procedures are described.
Results:
Five patients suffered biopsy proven invasive fungal sino-orbital infection (2 rhizopus, 1 mucor, 1 aspergillosis, 1 rhodotorula mucilaginosa/alternaria/hormographiella) related to comorbid conditions (leukemia, renal transplant, diabetic keto-acidosis, corticosteroid therapy, retained intraorbital foreign body) Adjuvant therapy supplementing systemic antifungal therapy included retrobulbar/peribulbar injection (3-5 mL of 2mg/cc AmphB) and sino-orbital irrigation (50-500cc of 0.2-0.5mmg/cc AmphB) Two patients who presented prior to onset of complete blindness (counting fingers, and 20/40 soon worsening to no light perception) in the affected eye maintained useful visual function at latest examination (20/80 and 20/25, respectively) Five patients showed improvement in orbital and motility examination parameters. No patient required orbital exenteration, or extensive disfiguring facial debridement.
Conclusions:
Adjuvant orbital therapy with Amphotericin B is safe and appears effective in controlling orbital fungal infection. In selected cases, it may prevent disfiguring surgery, may be associated with improvement in ophthalmoplegia, and may preserve visual function when begun prior to onset of complete blindness.
Retinopathy in Patients with Diabetic Ophthalmoplegia
First Author:
Lucas Trigler, MD, Oklahoma City, Oklahoma
Background:
Intuition suggests that the incidences of diabetic retinopathy and CN palsy are directly proportional, but this has not been proven.
Objective:
To review clinical characteristics, prevalence, and severity of retinopathy in patients with diabetes with cranial nerve (CN) III, IV, and VI palsies, and to determine if type or duration of diabetes, or severity of retinopathy correlates with cranial neuropathies.
Methods:
Retrospective chart reviews of patients with CN III, IV, or VI palsy were performed at the Bascom Palmer Eye Institute (BPEI) from 1/91 through 12/97 and at the Dean A. McGee Eye Institute (DMEI) from 1/94 through 7/01. Patients were included if DM was determined to be the etiology of the CN palsy. Prevalence and severity of retinopathy were compared with data from the Wisconsin Eye Study for Diabetic Retinopathy (WESDR) as a control.
Results:
Of 2,229 patients with ocular motor CN palsy, 307 (13.8%) were due to DM. The prevalence of CN involvement was: VI (50%), III (43.3%), and IV (6.7%). At each location, the prevalence of retinopathy with respect to duration of diabetes was lower in both IDDM and NIDDM Type II patients with diabetes as compared with controls (BPEI p = 0.009 and p = 0.005; DMEI p = 0.004 and p = 0.29). When data from both locations was combined, the difference was even more significant (IDDM p = 0.001 and NIDDM p = 0.006). There were no significant differences between the two locations in gender, type or duration of DM, age at presentation, or frequency of CN involvement. All three populations differ with respect to time period studied and racial distribution.
Conclusions:
Type II patients with diabetes with ocular motor CN palsy have significantly less diabetic retinopathy than controls. Theories that explain this observation will be presented.
Charles Bonnet Syndrome Precipitated by Brimonidine Tartrate Eye Drops
First Author:
Robert Tomsak, MD, Cleveland, Ohio
Background:
Brimonidine tartrate (BT) (Alphagan) is an alpha-2 adrenergic agonist marketed for treatment of primary open angle glaucoma (POAG) and may have neuroprotective effects (1). One report of acute delusional psychosis with auditory hallucinations in a 68-year-old man treated for POAG is published (2). Here I report two patients with bilateral vision and visual field loss from nonarteritic anterior ischemic optic neuropathy and optic nerve drusen who also had elevated intraocular pressures. Both developed formed visual hallucinations (Charles Bonnet syndrome; CBS) shortly after beginning the use of BT eye drops (3).
Objective:
To report Charles Bonnet syndrome precipitated by the use of brimonidine tartrate eye drops (Alphagan) in two elderly visually compromised women.
Methods:
Observational case series of two patients. Clinical office exams and telephone interviews.
Results:
Brimonidine tartrate use apparently precipitated the Charles Bonnet syndrome in both cases and cessation of drug did not stop hallucinations.
Conclusions:
Both patients described above were candidates for the CBS but neither had visual hallucinations prior to using BT. The hallucinations did not completely stop after BT was discontinued, although confusion rapidly cleared in Case 1. Visual hallucinations caused by oral clonidine, another alpha-2 adrenergic agonist, are well documented (4,5). Auditory hallucinations, depression, confusion and anxiety have been reported with BT (2) and clonidine (4,5). Brimonidine tartrate use may cause visual hallucinations when administered to elderly patients with significant bilateral vision and visual field impairment.
References:
1. Yoles E, Wheeler LA, Schwartz M. Alpha2-adrenoreceptor agonists are neuroprotective in a rat model of optic nerve degeneration. Invest Ophthalmol Vis Sci 1999; 40:65-73.
2. Kim DD. A case of suspected Alphagan-induced psychosis. Arch Ophthalmol 2000; 118:1132-33.
3. Schultz G, Melzack R. The Charles Bonnet syndrome: phantom visual images. Perception 1991; 20:809-25.
4. Brown MJ, Salmon D, Rendell M. Clonidine hallucinations. Ann Int Med 1980; 93:456-457.
5. Lavin P, Alexander CP. Dementia associated with clonidine therapy. Br Med J 1975; 1:628.
An Atypical Bruit
First Author:
Mitchell Wolin, MD, Greenville, South Carolina
Abstract:
A 46-year-old female started having diplopia about 5 days prior to presentation. This was initially noted when driving and then became more constant. She was aware of diplopia the prior week while in the hospital for a kidney biopsy. The patient had recently been under evaluation for a kidney problem. She had been found to have elevated urinary protein, and underwent kidney biopsy, and she required 2 units of blood the following day. She has had headaches for about 2 months. She had also been fatigued recently. She had been aware of a roaring sound in her head for about 5 weeks that was either constant or pulse like. This worsened with laying down. This roaring sound started about one week following an upper respiratory infection that subsequently resolved. PMII is notable for an old hear murmur. She has had headaches on a recurrent basis in the past measuring 16 ET in right gaze, 18 D in primary and 14 D in left gaze. Discs revealed 1+ edema OU. Auscultation of the head revealed a somewhat high-pitched bruit, best heard in the temples and consistent with the pulse rate. Review of the kidney biopsy showed mild focal global glomerular sclerosing change, suggestive of low-grade focal sclerosing nephropathy. It was debated whether to proceed directly to cerebral arteriography, given the suggestive findings of a dural carotid cavernous fistula. However, a CT scan was obtained which showed an apparent mass in the region of the torcula, with homogenous and intense enhancement with erosion of the inner table of the occipital bone. Angiography did not show any CC fistula, but did show findings of Significant flow through the mass and no obliteration of the veins. There is no arterial shunting to the tumor mass. A neurosurgeon felt that this did not represent a meningioma, and possibly representing an cosinophilic granuloma. An MRI scan was performed which showed the torcula mass. It was decided to proceed with an open biopsy of the mass, which was performed on 10-29-99 without complications. This revealed a plasmacytoma. She underwent bone marrow biopsy, which confirmed the impression of multiple myeloma. It was determined that the nephrotic syndrome was due to Bence Jones proteinuria. She subsequently underwent treatment with chemotherapy. She developed near renal failure after about 5 months, and died about 1 year after diagnosis. An audible cranial bruit in the setting of mild bilateral 6th nerve palsies and mild papilledema initially suggested the possibility of a carotid cavernous fistula. The finding of a mass lesion in the back of the head due to a plasmacytoma from undiagnosed multiple myeloma was quite unusual. The nephrotic syndrome was determined to be secondary to the urinary protein from the myeloma.
Isolated Pupil-Dilated Painful Third Nerve Palsy as an Initial Presentation of Systemic Lymphoma
First Author:
Grace Kao, MD, Orange, California
Background:
The rule of the pupil has implied that pupil-dilated third nerve palsy is usually due to a compressive lesion, and pupil-sparing to an ischemic metabolic or noncompressive, reversible lesion. This notation is challenged in some conditions of pupil-dilated third nerve palsy with systemic lymphoma.
Objective:
To report a case of complete third nerve palsy violate the rule of pupil and possible mechanism.
Methods:
Case report and review of literature.
Results:
A 41-year-old healthy white man developed a progressive painful left third nerve palsy over 2 weeks to a complete palsy with a fixed 7.5 mm pupil after a severe flu. He otherwise had normal neurologic and neuro-ophthalmological examination. Brain and orbit MRIs did not show any abnormality except more enhanced left superior ophthalmic vein than the right. Cerebral angiogram, CSF profile, cytology, virus titer, PCR and cultures of herpes viruses, Lyme disease, angiotensin-converting enzyme were all negative. Eye pain resolved after IV methylprednisolone 1 g/d for 3 days but not the ocular palsy until 6 weeks later. Two months after the onset, when left third nerve almost resolved, he had another Flu followed by left facial palsy and hoarseness. Repeated MRI of brain was negative. CSF showed 129 WBC, 83% lymphocyte, protein 91 mg/dl and rest of CSF bacteria and viral cultures, titers, PCR, ACE titer was negative as well as flow cytometry. Facial palsy resolved after one day IV methylprednisolone. Further workup revealed plural effusion and mediastinal mass on CT scan. Mediastinoscopic biopsy after steroid for 5 days revealed necrotic fibrotic tissue. He remained stable until 6 weeks later when he had dysphagia and breathing difficulty. The mediastinal mass recurred with pericardial effusion. CSF showed 219 WBC with 87% lymphocyte and 11% atypical lymphocyte, protein 160 mg/dl, glucose 66 mg/dl. Flow cytometry of CSF was diagnostic for T-cell lymphoblastic lymphoma. He was then treated with systemic and intrathecal chemotherapy followed by whole brain irradiation with remission until 3 months later when he developed severe multifocal motor sensory peripheral neuropathy. Left third nerve function has remained almost resolved.
Conclusions:
Isolated third nerve palsy with fixed dilated pupil without radiologically demonstrated lesion and normal CSF can be a preceding sign of systemic malignant lymphoma. A microinfiltrative process not radiologically visible of the third nerve proximal to the orbital apex is the presumptive mechanism. Only 4 reports in literature described isolated third nerve palsy in lymphoma and none had a complete palsy with a full blown pupil that recovered later despite systemic recurrence.
Adaptive Neural Mechanism for Listing's Law Revealed in Patients with Fourth Nerve Palsy
First Author:
Agnes Wong, MD, St. Louis, Missouri
Background:
During fixation and saccades, human eye movements obey Listing's law, which specifies the eye's torsional angle as a function of its horizontal and vertical position.
Objective:
To investigate whether the brain adapts to defective torsional control after fourth nerve palsy.
Methods:
Thirteen patients with fourth nerve palsy (11 chronic, 2 acute), and ten normal subjects were studied using scleral search coils. With head immobile, subjects made saccades to a target that moved between straight ahead and 8 eccentric positions. From the eye position data, we computed a plane of best fit, called Listing's plane. Violations of Listing's law were quantified by computing the `thickness' of this plane, defined as the standard deviation of the distances to the plane from the data points.
Results:
Patients with chronic fourth nerve palsy obeyed Listing's law in both the paretic and non-paretic eyes during fixation and saccades; however, Listing's planes of both eyes had abnormal orientations, being rotated temporally. In contrast, the paretic eye of patients with acute palsy violated Listing's law during saccades. During downward saccades, transient torsional deviations moved the paretic eye out of Listing's plane. Torsional drifts returned the eye to Listing's plane during subsequent fixation.
Conclusions:
During saccades, acute fourth nerve palsies violate Listing's law, whereas chronic palsies obey it, indicating that neural adaptation can restore Listing's law by adjusting the innervations to the remaining extraocular muscles. Although Listing's law is obeyed in chronic palsy, Listing's plane is rotated temporally, as a manifestation of excyclotorsion during downgaze and incyclotorsion during upgaze. In acute palsy, rapid torsional deviations and slow torsional drifts occur during and immediately after downward saccades. These saccadic intrusions are attributed to pulse-step mismatch, as a result of lesions in the trochlear nerve, which lead to an imbalance of phasic and tonic signals reaching the muscles.
Oscillopsia and Rotary Nystagmus, Synchronous with Heartbeat: a Treatable Form of Nystagmus
First Author:
Brian Younge, MD, Rochester, Minnesota
Abstract:
Two patients with oscillopsia and a rotary nystagmus synchronous with heartbeat were found in addition to have Valsalva-induced nystagmus. This has been videotaped for presentation. The cause of this was found to be a dehiscence between the superior semi-circular canal and the intracranial cerebrospinal fluid. Surgical treatment of this results in a cure of the nystagmus and oscillopsia.
The Use of Proton Magnetic Resonance Spectroscopy (1H-MRS) to Measure Lactate in the Ocular Vitreous Body in vivo
First Author:
Janet Rucker, MD, Atlanta, Georgia
Background:
Lactate is present in ocular vitreous at a high level and is increased in ocular pathology, such as retinal ischemia or metabolic diseases. Detection by 1H-MRS of elevated vitreous lactate in vivo would allow a non-invasive evaluation of retinal and optic nerve metabolism.
Objectives:
To assess the ability to record a consistent lactate signal with 1H magnetic resonance spectroscopy (1H-MRS) from the vitreous of human eyes in vivo.
Methods:
Four normal subjects and one patient with optic neuropathy were included. All 1H-MR spectra were acquired on the vitreous with a 1.5 T clinical whole body scanner using a standard head coil. A volume of interest of 1cm3 was placed on the center of the vitreous body. 1H-MR spectra were collected with water suppression. Lactate resonance was assigned by using the chemical shift of water as reference and measuring the J-couple parameter of this resonance.
Results:
Lactate was identified as the dominant resonance in each vitreous body tested (at 1.38 ppm chemical shift).
Conclusions:
Characterization of the localized MR spectrum of human vitreous in vivo is feasible. We identified lactate as the dominant resonance in the vitreous. Quantification of the lactate concentration might be possible by utilizing the water resonance as an internal reference. The detection of a reliable lactate peak in the human ocular vitreous is the initial step in application of 1H-MRS to retinal and optic nerve disease.
The Clinical Utility of PET Scanning in the Diagnosis of Essential Blepharospasm
First Author:
John Kerrison, MD, San Antonio, Texas
Background:
Essential blepharospasm is a disorder characterized by bilateral episodic contractions of the orbicularis oculi muscles and may be difficult to diagnose in its early stages. PET (18fluorodeoxyglucose [18FDG) neuroimaging in patients with essential blepharospasm has suggested abnormal metabolism in the striatum, thalami, pons, and cerebellum. The value of this test as a clinical tool remains unexplored.
Objectives:
The purpose of this study is to assess the potential utility of PET (18FDG) in the diagnosis of essential blepharospasm.
Methods:
PET scanning with 18FDG in patients with essential blepharospasm and age/gender-matched controls was performed followed by comparative analysis of the mean count per pixel in several regions of interest.
Results:
Analysis of 4 patients with essential blepharospasm and 5 controls demonstrated no differences in the mean count per pixel of the caudate, putamen, striatum, thalami, cortical hemispheres, cerebellum, or pons (t test, 2 tails).
Conclusions:
PET (18FDG) neuroimaging does not appear to be clinically useful in the diagnosis of essential blepharospasm.
Inhibitory Mechanisms in Direction Selective Retinal Ganglion Cells that Drive Optokinetic Nystagmus
First Author:
Steven Stasheff, MD, PhD Boston, Massachusetts
Abstract:
We describe new features of null inhibition that help explain the function of direction selective retinal ganglion cells (DSGCs), which generate the earliest visual input driving optokinetic nystagmus (OKN; Oyster et al, 1972). This asymmetric wave of inhibition shadows a moving stimulus on its null side (Wyatt and Daw, 1975). We recorded DSGCs in the rabbit retina in vitro while stimulating with single or paired moving bars of light, showing that 1) a bar moving through the receptive field in the preferred direction strongly inhibits the response to a second bar following it; and 2) the spatial extent and duration of this inhibitory wave correspond to prior predictions, to the known spatial and temporal frequency tuning of DSGCs, and to the velocity tuning of OKN. This suggests that the same inhibition may govern direction selectivity as well as the spatial and temporal response properties of these cells, and hence of OKN. From our experiments, further insights into this inhibitory mechanism include: 1) it is likely postsynaptic; 2) interactions between dendritic layer-specific ON and OFF inputs, activated by leading and trailing edges of moving bars, contribute to null inhibition and likely are mediated by a multistratified amacrine cell; and finally 3) the total amount of inhibition conferred on the cell, measured by probing with a stationary flashing spot, is the same for stimuli moving in the preferred or null direction. Thus, in contrast to classic integrate and fire neurons, the DSGC must compute motion direction within local dendritic subunits. A histologic examination of the spatial relationship between excitatory and inhibitory synapses within the dendritic arbor of a DSGC revealed no systematic arrangement (such as alignment of synapses along the preferred-null axis), so identifying the precise nature of local dendritic interactions that mediate this asymmetric inhibition is an avenue for future study.
Anemia and Intracranial Hypertension
First Author:
Valerie Biousse, MD, Atlanta, Georgia
Background:
Although rarely reported, anemia is considered a classic association with idiopathic intracranial hypertension (IIH). The underlying mechanisms remain unknown.
Objectives:
To elucidate the relationship between anemia and raised intracranial pressure (ICP).
Methods:
Retrospective case-series and review of the literature. Inclusion criteria included papilledema, neuroimaging ruling-out a space-occupying lesion, and documented anemia.
Results:
3 female nonobese patients with confirmed IIH (normal MRI/MRV, normal CSF, elevated ICP), and 1 male non-obese patient with presumed IIH (normal CT, no LP) were personally evaluated. All had bilateral papilledema associated with peripapillary hemorrhages. 2 had retinal cotton wool spots (CWS), one had retinal hemorrhages. All had severe iron deficiency anemia. Their symptoms/signs improved dramatically after treatment of the anemia. We found 26 well documented cases in the English and French literature. Among those, 9 were excluded from our analyses (8 had confounding disorders, and 1 had cerebral venous thrombosis (CVT)). In the remaining 17 cases, isolated raised ICP associated with anemia was the most likely diagnosis, although in none of these cases was CVT excluded. There were 13F/4M, mean age 26yo [4-56]; 7 were obese; all had bilateral papilledema, associated with CWS in 7, and retinal/preretinal hemorrhages in 10; 10 had chronic headaches, 2 had tinnitus, 4 complained of fatigue, 4 had Vith nerve palsies. LP was obtained in 9 patients (elevated ICP in all; mean 376mm [220-600]). All 17 had severe anemia (mean Hct 18.6% [17-25]) secondary to iron deficiency in 10, B12 deficiency in 2, aplastic anemia in 3, transient erythroblastopenia in 1, and unknown in 1. Treatment included successful reversal of the anemia in all 17, and LP in 9 patients. Visual prognosis was good in 15 patients and unknown in 2.
Conclusions:
Anemia may play a role in the occurrence of raised ICP and papilledema. Although only a few cases in the literature support this association, it may be more common than previously thought. Since most patients are not known to be anemic when papilledema is discovered, we suggest that a CBC be obtained in patients with IIH, especially in the absence of known associated factors such as obesity or medications. The underlying mechanisms remain unknown, but CVT should be carefully excluded.
A Recondite Case of Parinaud Syndrome and Multiple Sclerosis
First Author:
William Lee, MD, Lexington, Kentucky
Abstract:
Parinaud syndrome, also known as the dorsal midbrain syndrome or sylvian aqueduct syndrome, may include a combination of the following findings: paralysis of upward gaze, defective convergence, convergence-retraction nystagmus, light-near dissociation, nystagmus, skew deviation, and upper lid retraction. Parinaud syndrome is typically the consequence of mass lesions compressing the tectum. We describe an unusual case in which a solitary midbrain lesion, felt to represent a tectal plate glioma, presented as Parinaud syndrome. On further examination the lesion was determined to represent a demyelinating process heralding multiple sclerosis. We discuss the etiologies and pertinent clinical tests for evaluation of Parinaud syndrome.
Ocular Toxicity Induced by High-dose Tamoxifen
First Author:
Shlomo Dotan, MD, Jerusalem, Israel
Background:
Tamoxifen treatment was associated with refractile crystals in inner retina, macular edema, retinal pigment epithelium abnormalities, optic neuropathy, cataract and vortex keratopathy. The incidence of such ocular toxicity has been reported to be as high as 6.3% in breast cancer patients treated with low doses of tamoxifen. The cumulative levels that could carry an increased risk of toxicity in high-dose treatment are not yet well defined.
Objectives:
To assess ocular toxicity of high-dose tamoxifen synthetic nonsteroidal antiestrogen drug currently used in high doses for glioblastoma.
Methods:
Sixteen patients treated with high-dose tamoxifen (240mg/day) for high-grade brain tumors were included in the study. Six of them were treated for a period of over one year at time of exam. When the periodic ophthalmological examination revealed impaired visual acuity or refractile retinopathy, visual function was further assessed by static perimetry, color vision, full-field and focal electroretinography testing.
Results:
Of the six patients treated with high-dose tamoxifen for more than one year, five showed signs of ocular toxicity. The clinical findings included decreased visual acuity, color vision and visual field abnormalities, keratopathy and macular refractile bodies. Full-field electroretinograms (ERGs) revealed impaired rod function, and focal ERGs showed decreased foveal cone function in four patients. Ocular toxicity was only partially reversible following the discontinuation of the tamoxifen treatment.
Conclusions:
While low-dose tamoxifen treatment has been reported only rarely to cause ocular toxicity, the high-dose treatment of this drug could be the cause of early and frequent signs of toxicity. Baseline ophthalmologic assessment and periodic follow-up exams should be recommended in these patients. Discontinuation of the treatment at the earliest signs of retinal toxicity should be considered, as such changes could be partially reversible.
Two Cases of Primary HIV Optic Neuropathy
First Author:
Harry O'Halloran, MD, San Diego, CA
Abstract:
Two HIV-positive patients presented with optic atrophy of unknown etiology. One, a 27-year-old female, presented with a six-month history of worsening fatigue, weight loss, memory loss, and progressive vision loss in both eyes. The second patient, a 25-year-old male, presented with vision loss and recurrent headaches. These patients are presented in detail with neurologic, ophthalmologic, laboratory, and radiographic findings. In addition, similar cases from the literature are reviewed. We postulate that both patients had a primary HIV optic neuropathy and discuss potential mechanisms of pathogenesis.
Localization of the Site of Abnormality in Papillo-renal Syndrome
First Author:
Jeffrey Odel, MD, New York, New York
Objectives:
To investigate the origin of the visual field defects in two patients with papillo-renal syndrome by recording multifocal electroretinograms (mfERG). The papillo-renal syndrome, inherited autosomal dominantly, consists of bilateral optic disk anomalies associated with hypoplastic kidneys. The optic discs are vacant without a central retinal artery but with cilioretinal vessels exiting the disc. It has been speculated that the visual field defects are retinal in origin (1).
Methods:
In both patients, mfERGs were recorded with a bipolar Burian-Allen electrode after the pupil was dilated and the cornea anesthetized. The visual stimulus consisted of 103-scaled hexagons (50¡ in diameter). One 7-minute run was recorded from OU. The recordings were controlled with VERIS software from EDI.
Results:
Both patients had vacant discs with absence of the central retinal vascular system and multiple cilioretinal arteries and were status postrenal transplantation. The second patient tested positive for the PAX 2 gene mutation. Both patients had normal intra-ocular pressure. The visual field displayed bi-nasal field loss that crossed the horizontal in the first patient; in the second a nasal defect was present OD and a temporal defect OS. The mfERG records for both patients were within normal limits OU.
Conclusions:
Because the patients' mfERGs were normal, it is unlikely that they had either a retinal developmental anomaly or had suffered a serous retinal detachment. Given what is known about the cellular origins of the mfERG, it appears that the retinal blood supply is sufficient to maintain normal retinal activity at least up to and including the bipolar cells.
Reference:
1. Parsa CF, Silva ED, Sundin OH, et al. Redefining papillorenal syndrome: an underdiagnosed cause of ocular and renal morbidity. Ophthalmology 2001, 108:738-49.
The Characterization and Comparison of OHTS Abnormal Visual Field Classifications Using the 24-2 versus the 30-2 Testing Strategies
First Author:
John Keltner, MD, Sacramento, California
Background:
A classification system was developed for the Ocular Hypertension Treatment Study (OHTS) to describe visual field (VF) abnormalities.
Objectives:
To characterize VF abnormalities in OHTS patients and to compare classifications using the 24-2 versus the 30-2 Humphrey vf testing strategies.
Methods:
Three certified readers independently classified a subset of 230 (460 hemifields) OHTS abnormal VFs using 17 abnormality classifications. Readers assigned separate classifications to the upper and lower hemifields using the Total and Pattern Deviation probability plots as the primary basis for the classifications. If 2 out of 3 readers agreed, then a final abnormality classification was determined for that hemifield. If 2 readers did not agree, then the VFs were adjudicated by group consensus. After a final classification was made for each hemifield, we compared the 30-2 abnormality classifications with the 24-2 abnormality classifications and determined the frequency and location of differences.
Results:
Of the 460 hemifields, 305 (66%) had the same type and location of abnormality using both testing strategies and 155 (34%) had either a different type/location of abnormality or were classified as normal using the 24-2 strategy. Eighty three (54%) of the 155 had a different type/location of abnormality using the 24-2 strategy and 72 (46%) were classified as normal using the 24-2 strategy. Sixty (83%) of the 72 classified as normal using the 24-2 strategy, were classified as peripheral defects using the 30-2 strategy. Specifically, these peripheral defects included the following: temporal wedge (19), partial peripheral rim (14), inferior depression (13), superior depression (8), and nasal step (6).
Conclusions:
We found the 24-2 testing strategy may reduce artifactual defects, which are evident by the 34% of abnormal hemifields that either had a different type/location of abnormality (18%) or returned to normal (16%). However, it is uncertain how many early glaucomatous defects might be missed.
Cat-scratch Encephalopathy
First Author:
Alvin Seah, MD, Atlanta, Georgia
Background:
Cat scratch disease is a common cause of ocular disease. It also uncommonly causes an encephalopathy, with variable neuro-imaging findings.
Objectives:
To describe a patient with cat-scratch encephalopathy occurring after ocular involvement and to present a review of the literature regarding neuro-imaging findings.
Methods:
Single case report and review of the literature.
Results:
A 23 year-old woman presented with a branch retinal artery occlusion in the OD. Bartonella titers were elevated at 1:1024 and a course of ciprofloxacin was prescribed. The next month, she reported two nocturnal seizures, a decrease in memory and attention, and clumsiness. A MRI of the brain showed a non-enhancing lesion in the right parietal gray matter with normal DWI, and a repeat Bartonella titer was >1:2048. Of 33 case reports of cat-scratch encephalopathy with reported neuro-imaging findings, 21 had normal neuro-imaging (of which 12 were normal on both CT and/or MRI, and the rest on CT only), and only 12 (36.3%) had abnormal neuro-imaging (5 on CT only and the rest on either MRI alone or both CT/MRI), and none had gray matter lesions similar to this patient. Various pathophysiologic mechanisms have been proposed in the literature, including direct CNS invasion, host immune response, elaboration of a neurotoxin, and vasculitis.
Conclusions:
Cat-scratch disease can manifest as both ocular disease and encephalopathy. Neuro-imaging abnormalities can involve the gray matter.
Effects on Congenital Nystagmus (CN) of Combined Gaze-angle and Vergence Variation: Therapeutic Implications
First Author:
Louis Dell'Osso, PhD, Cleveland, Ohio
Objectives:
To investigate the observation that once CN is damped by convergence in a binocular subject, it remains damped over a range of gaze angles.
Methods:
Ocular motility recordings were made using infrared reflection during fixation of targets at gaze angles varying between ±20° at different values of convergence ranging from far to 20D. The expanded Nystagmus Acuity Function (NAFX) was used to evaluate the CN waveform's relation to potential visual acuity at all fixation points.
Results:
During far fixation the subject exhibited a classic null (high NAFX value) with lower NAFX values at gaze angles in both lateral directions from the null. During near fixation, the NAFX values were higher both at the null and at gaze angles to both sides of the null region; that is, the null region was broadened. When plotted for a fixed gaze angle, the variation of NAFX with vergence exhibited hysteresis, being greater during divergence than convergence.
Conclusions:
The hysteresis exhibited during vergence implies that the acuity achieved when fixating a target would be higher if one first fixated on a nearer point and then diverged to the target. Damping CN by means of induced convergence, either with base-out prisms or bimedial recession surgery, not only takes advantage of the vergence null (usually stronger than a coexisting gaze-angle null) but also provides a wider range of gaze angles with higher potential acuity. The null-broadening effects of vergence mimic those recently discovered for tenotomy.
Oscillating Scotomas of Migraine Auras or Induced See-Saw Nystagmus (SSN) with Loss of Vertical Fusion in Congenital Nystagmus (CN)
First Author:
Louis Dell'Osso, PhD, Cleveland, Ohio
Objectives:
To describe and investigate observations made during migraine auras and one episode of loss of vertical fusion in an individual with horizontal-torsional CN.
Methods:
Ocular motility recordings were made during fixation of targets in primary position and various amounts of prism-induced vertical diplopia.
Results:
Instead of classic migrainous auras, a subject with CN experienced horizontal oscillation (i.e., oscillopsia) of the scintillating scotomas; the other characteristics of the auras were classic. A single, unrelated instance of vertical diplopia produced vertical oscillopsia of one of the two resulting visual fields. During normal fixation of a vertically elongated + sign (i.e., a long vertical bar with a short horizontal bar crossing it at its center), neither diplopia nor oscillopsia was perceived regardless of where on the vertical portion of the target the subject fixated. When vertical diplopia was induced (producing two vertically displaced images of the target), oscillopsia occurred. If either the upper or lower horizontal image was fixated, the other appeared to oscillate vertically. If the subject fixated on a point on the vertical bar between the two disparate horizontal images, both images appeared to oscillate vertically in counter phase. Ocular motor recordings revealed an induced SSN that accompanied the loss of vertical fusion.
Conclusions:
Classical migrainous auras appear to oscillate in the plane of CN, mimicking the oscillation of a flashed afterimage. In a binocular individual with CN, breaking vertical fusion induced vertical oscillopsia of the non-fixated image or of both images if neither was fixated. The loss of vertical fusion appears to be associated with both induced SSN in CN and the SSN of a chiasma.
A Hypothetical Fixation System Capable of Extending Foveation in Congenital Nystagmus
First Author:
Louis Dell'Osso, PhD, Cleveland, Ohio
Objectives:
To examine the roles of position and velocity signals in the implementation of a fixation system. This system should act in concert with the smooth pursuit system, allowing the extension of foveation periods by slowing the runaway slow-phase oscillation when position and velocity error fall within given limits.
Methods:
The fixation subsystem was incorporated into a robust ocular motor system (OMS) model capable of simulating a multitude of normal responses as well as those made in the presence of abnormalities such as congenital nystagmus (CN), latent/manifest latent nystagmus, gaze-evoked nystagmus, myasthenia gravis, and others. We constructed two candidate fixation subsystems models. The subsystem models were tested first in isolation, verifying their basic functionality. The subsystems were then integrated into the more complex and biologically relevant OMS model, presented previously.
Results:
The resulting OMS model demonstrates that foveation duration can be increased to simulate the extended foveation periods commonly observed in complex CN waveforms such as pendular with foveating saccades and pseudopendular with foveating saccades. Only intervals following foveating saccades were extended, not those following braking saccades. This was achieved by monitoring eye position and velocity and providing appropriate control of the commands sent to the OMN.
Conclusions:
The OMS model provides possible mechanisms for integrating a fixation system that acts effectively, even in the presence of the high-velocity oscillations of the smooth pursuit system typical in CN. The result is a slowing of the eye during target foveation, creating a more useful period of low-velocity retinal slip that is available to the visual system; this allows for greater visual acuity.
The Fainting Lawyer: A New Cause of Pseudo-pseudotumor Cerebri
First Author:
William Fletcher, MD, Calgary, Alberta
Abstract:
A 35-year-old lawyer was referred for assessment of papilledema, which was found incidentally. He felt well generally and had no headache or visual obscurations. Nine months earlier, over a period of four months, he had several episodes of feeling faint, triggered by sitting in a semi-recumbent position. He lost consciousness briefly during three of the episodes but was able to abort most of them by quickly sitting upright. He took no medication. Neuro-ophthalmological and perimetric examination showed normal findings other than bilateral moderate optic disc edema and mild blind spot enlargement. CT scan of the head and orbits was normal. Lumbar puncture revealed an opening pressure of 350 mm. CSF cell counts and protein were normal. MRI and MRV showed no intracranial abnormalities but there was an extracranial, rounded, T2-hyperintense, enhancing lesion, measuring 2 × 2 × 3 cm, located at and below the right jugular foramen. Catheter angiography showed an avascular tumor, which displaced the internal carotid artery and jugular vein. Venous drainage was predominantly through the right transverse, sigmoid and internal jugular veins and there was good venous flow. Extracranial skull base exploration revealed an encapsulated tumor attached to the right vagus nerve. The tumor was removed uneventfully and found to be a schwannoma. Examination two months later showed resolution of the papilledema.
Extracranial tumors rarely cause intracranial hypertension. Papilledema has been reported with involvement of the jugular foramen by metastatic lesions (1) or large glomus jugulare tumors with intracranial extension (2). Rarely, patients with small glomus jugulare tumors present with papilledema (3,4). Vagal schwannoma may cause paroxysmal syncope (5) and should be considered in the differential diagnosis of CT-negative intracranial hypertension, especially for patients who have both conditions.
Coordination of Eye and Head Movement in Parkinson's Disease
First Author:
Paul Wetzel, MD, Richmond, Virginia
Background:
Parkinson disease (PD)is a progressive neurologic movement disorder caused by degeneration of dopaminergic cells in the substantia nigra resulting in hypokinesias, rigidity and tremor. The disease can also affect other motor and sensory function including cognitive abilities, contrast sensitivity, color perception and the control of eye movements. Medications can minimize the effects of PD but become less effective as the disease progresses. Deep Brain Stimulation (DBS) employs a stimulating electrode surgically implanted within the globus pallidus or the ventrointermediate nucleus of the thalamus to minimize tremor. We conducted a preliminary study of the relationship between eye and head movements of PD patients receiving DBS.
Objectives:
To present preliminary data and establish methods to examine the relationship between eye and head movements of PD patients including those with DBS, through the Richmond Veterans Affairs Medical Center, Parkinson's Disease Research, Education and Clinical Center (PADRECC).
Methods:
Over the course of several months we recorded the eye and head movements of one PD patient receiving initially unilateral and then bilateral implantable DBS stimulators. The patient performed fixation and vertical and horizontal visual tracking tasks while unrestricted head and eye movements were measured at 120 Hz using a magnetic head tracking system and a modified pupil-corneal reflection system. Head and eye movements were analyzed for position, velocity, amplitude, duration and gaze.
Results:
Head and eye movement data showed random periods of uncorrelated, uncompensated eye and head movements observed during the presence and absence of tremor.
Conclusions:
Preliminary results indicate that PD can adversely affect the coordinated relationship between eye and head movement resulting in destabilized gaze control and impaired visual activities.
Doxil Chemomyectomy: 2 Year Results of the Phase 1 Trial
First Author:
Jonathan Wirtschafter, MD, Minneapolis, Minnesota
Background:
Doxil is a liposome-encapsulated preparation of doxorubicin that is a skin irritant but not a vesicant like the unencapsulated drug. Doxorubicin chemomyectomy is the only proven non-surgical treatment that effects a permanent cure or significant amelioration of essential blepharospasm and hemifacial spasm. Patients who completed the doxorubicin treatment series have been followed for up to 10 years. The median total dose/patient required for cure was 9 mg. although some patients required up to 17 mg. The risk of skin complications significantly limited acceptance of the prior drug.
Objectives:
To present the results two years after completion of treatment of the two patients who participated in the Phase I trial of Doxil chemomyectomy for eyelid spasms.
Methods:
The two patients received total doses of 24 and 21 mg of Doxil in their upper eyelids with 5 injections/eye and 2 injections into their corrugator muscles within 13 months. Botox rescue treatment of residual spasm was always available and encouraged.
Results:
Unlike doxorubicin, Doxil injections in the upper lids always moved immediately into the lower lids. This necessitated a protocol change to limit injections to the upper lids. After completion of the assigned Doxil treatment the mean interval between Botox treatments increased from 91 to 130 days for the high dose patient and from 70 to 128 days for the low dose patient. No complications occurred except for the expected erythematosus, which always cleared.
Conclusions:
Doxil chemomyectomy has great promise for permanently alleviating or relieving eyelid spasms. Comparing Doxil to doxorubicin, Doxil is much safer for the skin but with at least a 50% reduction in efficacy per mg. The Phase II trial is recruiting patients who will receive total doses of up to 31.5 mg.
Non-arteritic Ischemic Optic Neuropathy in Young Patients Compared with Older Patients
First Author:
Ruth Huna-Baron, MD, Tel Aviv, Israel
Objectives:
To compare clinical features of patients with nonarteritic anterior ischemic optic neuropathy (NAION) under 50 years of age to older patients.
Methods:
Review of medical records of all consecutive patients diagnosed with NAION at Sheba Medical Center and Kaplan Medical Center from 1993-2001. Associated medical conditions, optic disc crowding and second eye involvement were compared between the two groups.
Results:
Thirty-three cases under 50 (17%) were found among 198 patients diagnosed with NAION. Age at onset ranged from 22-50 years compared with 50-85 years in the older group. Male predominance was noted in both groups but was higher in the younger group [27/33 (82%)] than in the older group [101/165 (61%)]. Crowded discs were recorded in 55% (18/33) of the younger group compared with 36% (60/165) in the older group, which appeared statistically significant. Hypercholesterolemia was found in 12 (36%)patients of the young cases compared with 43 (25%) of the older cases. Systemic hypertension and diabetes mellitus were more frequent in the older group (47%, 37%; 27%, 27% respectively). Second eye involvement was present in 30% of the younger group compared with 20% in the older group.
Conclusions:
NAION is infrequent under the age of 50 and usually requires differentiation from optic neuritis. In our group of younger patients it was associated with known risk factors especially crowded disc and hypercholesterolemia. Second eye involvement was more frequent among the younger patients. Considering that the visual loss event led to the diagnosis of systemic conditions in some of the cases, it seems important to look for these conditions in young patients with NAION.
Long-term Visual Prognosis for Suprasellar (Tuberculum Sellae) Meningiomas
First Author:
Carlos Chicani, MD, Baltimore, Maryland
Objectives:
To determine the long-term (>10 years) visual and neurologic outcome in patients with suprasellar meningiomas.
Methods:
Retrospective case series
Results:
Twenty-one patients with suprasellar meningiomas were evaluated. All patients presented with visual complaints. Two patients who were not treated experienced progressive loss of vision in both eyes during follow-up. Among the 19 patients treated, all underwent initial surgery to resect the lesion. The surgery was associated with a 5% mortality rate, an 11% incidence of neurologic morbidity, and a 32% incidence of visual morbidity. Over the follow-up period, seven of the treated patients (37%) developed neuroimaging evidence of either tumor recurrence or growth of residual tumor, with the mean time of 10.7 years. Five of these patients subsequently underwent further surgery, one of whom also received conventional fractionated radiotherapy. Three additional patients received conventional radiation therapy, two shortly after their initial surgery, and one at the time of evidence of recurrent tumor 5 years after initial surgery. Among treated patients, visual acuity initially improved postoperatively in 36% of eyes, remained stable in 47% of eyes, and worsened in 17% of eyes. At final examination, 72% of the patients had visual acuity of 20/40 or better in at least one eye. Patients who underwent only a single surgical procedure or a single surgical procedure followed by radiotherapy shortly after surgery had a better visual outcome than patients who underwent more than one surgical procedure or who had radiotherapy at the time of tumor growth or recurrence.
Conclusions:
The long-term visual prognosis for suprasellar meningiomas is best when patients are treated shortly after diagnosis. The primary mode of therapy is surgery; however, tumor recurrence may occur, often more than 10 years following surgery. Thus, patients should be counseled regarding the need for long-term clinical examinations and serial neuroimaging.
Role of Tumor Necrosis Factor in Orbital Pseudotumor
First Author:
Austin Coleman, DO, Grand Rapids, Michigan
Background:
Orbital pseudotumor is a painful inflammatory process, which can be difficult to treat. It often responds to corticosteroids, but the hazards of chronic steroid use are widely known. These side effects necessitate the consideration of alternative anti-inflammatory medications for relief in some patients. Methotrexate, Cytoxan, and other NSAIDs have been used to replace or decrease the requirement of steroid therapy. Tumor necrosis factor alpha is a pro-inflammatory protein produced by immune cells, which is thought to play a role in chronic inflammation. Infliximab, a monoclonal antibody, is a tumor necrosis factor alpha-blocker approved by the FDA for intravenous treatment of Crohn's disease, and has been indicated for adjunct therapy in rheumatoid arthritis. We describe a case of orbital pseudotumor, which responded well to Infliximab administration.
Objectives:
To report the response of a patient with orbital pseudotumor to treatment with tumor necrosis factor alfa-blocker for concomitant Crohn's disease.
Results:
A 34-year-old female with a history of Crohn's disease originally developed painful diplopia in 1996 consistent with idiopathic orbital inflammation. Prednisone had been successful in alleviating symptoms, however recurrence of pain had prompted reinstitution of prednisone on at least three occasions. Diplopia persisted, and a rheumatology consultation initiated methotrexate with little benefit. Concomitantly, she also had multiple bouts with Crohn's disease requiring surgical intervention for rectovaginal fistula and resection of her ileocolic anastomosis.
Ultimately, due to the severity of her Crohn's outbreaks, even on methotrexate, she was started on Infliximab. After receiving her first dose of Infliximab, she experienced no diplopia for 4 weeks without adjuvant steroids.
Conclusions:
This improvement suggests that tumor necrosis factor may play a role in the pathogenesis of orbital pseudotumor. Ultimately, tumor necrosis factor blockers may be useful in the treatment of this inflammatory disease. Further study is warranted to evaluate the effectiveness of this treatment.
A Bayesian Network Model of the Diagnosis of ocular Myasthenia Gravis: Definition and Practical Significance of a New Decision Support Tool
First Author:
Preston Calvert, MD, Alexandria, Virginia
Background:
The diagnosis of ocular myasthenia gravis (MG) is often uncertain. Decisions involving invasive diagnostic studies, as well as potentially harmful therapy depend on assessing the likelihood of MG. Bayesian network models allow the conditional probability of a diagnosis to be evaluated in light of the knowledge available about a number of associated clinical findings. Properly structured probabilistic networks help avoid the problems of assuming conditional independence of clinical findings in simpler Bayesian models of diagnosis.
Objectives:
A Bayesian network probabilistic model of the diagnosis of ocular MG is presented. Implications for the effective evaluation of a patient with diplopia or ptosis are discussed.
Methods:
A systematic review of the clinical, serologic, electrophysiologic, and pharmacologic data that relate to the diagnosis of ocular MG was conducted. A Bayesian network probabilistic model was defined that incorporates the effects of the conditional dependence of related clinical data. Conditional probabilities of the various phenomena in ocular MG were derived from literature sources. Estimates of prior probabilities of phenomena in patients with diplopia or ptosis were estimated from literature sources or the beliefs of an experienced clinician. The effects of various sequences of data elicitation on the posterior probability of ocular MG were evaluated.
Results:
Clinical neuro-ophthalmologic findings with high specificity for ocular MG have great value in raising the probability of the diagnosis. Serologic, electrophysiologic, and pharmacologic testing can be structured in a sequence that leads parsimoniously to a high probability of MG, and may spare some suspected MG patients unnecessary invasive testing. Persistent evaluation may lead to a high probability of MG, even when initial results in the diagnostic process are uninformative.
Conclusions:
Implementing a Bayesian network model of ocular MG diagnosis may be useful in structuring the evaluation of patients with diplopia or ptosis. Model assumptions should be adjusted to match the setting in which it will be applied.
A Spectrum of Midbrain Tegmental Strokes: Review of 3 Cases
First Author:
Clifton Otto, MD, Tacoma, Washington
Background:
Midbrain infarcts are traditionally classified in terms of Benedikt's, Claude's, Nothnagel's, Parinaud's, and Weber's syndromes. While these classifications can be helpful when lesions obey specific boundaries, there are instances where implication of a particular syndrome is imprecise. We present three different cases of ischemic midbrain infarcts with overlapping clinical and radiologic findings.
Objective:
To present three cases of midbrain strokes with varied clinical and radiologic presentations.
Methods:
Case reports with discussion of findings and radiologic correlations.
Results:
The first patient presented with bilateral vertical gaze paresis, a sluggish left pupil and convergence retraction nystagmus suggesting Parinaud's syndrome. However, MRI showed an acute ischemic medial left mesencephalic tegmental infarct involving the red nucleus with extension into the thalamus suggestive of Claude's or Benedikt's syndromes. The second patient presented with fluctuating mental status, normally reactive pupils, and absence of vertical gaze again suggesting Parinaud's. By contrast, the MRI showed acute infarction of the rostral left paramedian mesencephalon, left cerebral peduncle, and ventral thalami consistent with Weber's or Benedikt's. The third patient presented with depressed mental status, dysarthria, bilateral ptosis, and a right third nerve paresis suggestive of a central tegmental lesion. MRI showed an acute infarct of the caudal right paramedian mesencephalic tegmentum extending into the cerebral peduncle once again suggestive of Weber's or Benedikt's.
Conclusions:
Midbrain lesions may not always respect the boundaries of the traditional midbrain syndromes. In the three cases presented signs and symptoms did not coincide precisely with the radiologic findings. This may be explained by individual anatomic variations, pre-existing ischemic brain injury, incomplete understanding of neuroanatomic pathways, and by improved definition of anatomic lesions due to advancements in neuro-imaging techniques.
Idiopathic Recurrent Neuroretinitis: Effects of Immunosuppression
First Author:
Valerie Purvin, MD, Indianapolis, Indiana
Background:
Recurrent neuroretinitis (NR) is an unusual condition in which otherwise healthy individuals experience episodes of acute monocular visual loss with optic disc edema and macular star formation. Episodes are typically followed by permanent visual loss which in some cases is severe and disabling. The cause of this syndrome has not been determined; some form of inflammatory process, perhaps on an autoimmune basis, has been suspected. Treatment of the acute attack in recurrent NR has not been of benefit in reversing visual loss.
Objectives:
We sought a form of prophylactic therapy that might prevent additional episodes. To this end, we have treated some of these patients with ongoing immunosuppressive agents.
Methods:
The charts of 30 patients with recurrent NR were reviewed. We identified 7 patients who were treated with low dose alternate day prednisone and/or azathioprine in whom adequate follow-up information was available. For each patient we calculated the number of attacks per year before and after treatment then combined these values to derive an average attack rate for the group.
Results:
We found a rate of 0.580 attacks per year prior to immunosuppressive therapy which decreased to 0.208 attacks per year following initiation of immunosuppressive treatment. This represents a reduction of 65% in attack frequency with the use of long-term immunosuppression.
Conclusions:
Based on this data, ongoing immunosuppression may be effective in reducing the number of episodes of recurrent visual loss in this syndrome.
Optic Neuropathy after LASIK
First Author:
Wayne Cornblath, MD, Ann Arbor, Michigan
Background:
Laser in situ keratomileusis (LASIK) is an increasingly common ophthalmic procedure done to correct myopia, hyperopia and astigmatism. Most complications relate to creation of the flap or are optical in nature, glare etc. Optic neuropathy has rarely been reported as a complication of LASIK.
Objectives:
Report 3 cases of LASIK induced optic neuropathy, review the literature and discuss possible mechanisms of injury.
Methods:
Case report.
Results:
3 patients were seen at 3 academic centers with unilateral optic neuropathy occurring 1-7 days after otherwise uneventful LASIK surgery. One patient had a long history of migraine. All patients had afferent pupillary defects and visual field defects, with varying levels of visual acuity and funduscopic appearance. There was some improvement over time in either visual field or acuity in 2 patients. Evaluation for other causes of optic neuropathy was negative.
Conclusions:
Optic neuropathy is a rare occurrence after LASIK. Possible mechanisms include ischemia to the nerve during suction or mechanical trauma. In one patient migraine might have been an additional risk factor.
Extrascleral Extension of Choroidal Melanoma Mimicking Primary Optic Nerve Tumor
First Author:
Dan Boghen, MD, Montreal, Quebec
Background:
Juxtapapillary choroidal melanoma with extrascleral extension presenting as a primary optic nerve tumor
Objectives:
To report the unusual presentation of an unrecognized juxtapapillary choroidal melanoma with extrascleral extension simulating a primary optic nerve tumor.
Methods:
Case report with review of clinical, radiologic and histopathologic records.
Results:
A patient presented with signs of compressive optic neuropathy and disk edema. CT scanning, magnetic resonance imagery and B-scan ultrasonography initially pointed toward a primary optic nerve tumor. Subsequent fundus examination disclosed a juxtapapillary pigmented choroidal lesion. The patient underwent enucleation with a long optic nerve section. Histopathologic analysis confirmed the diagnosis of a small juxtapapillary choroidal melanoma with extrascleral extension within the meninges compressing the optic nerve.
Conclusions:
Although extrascleral extension of choroidal melanoma usually occurs in eyes with medium or large intraocular tumors, it can also originate from small, unrecognized juxtapapillary tumors, thus simulating a primary optic nerve lesion.
Acute Ophthalmoplegia and Mydriasis Associated with IgG Anti-GQ1b Antibody
First Author:
Lee Snyder, MD, Baltimore, Maryland
Background:
The presence of IgG anti-GQ1b antibodies has been associated with the ophthalmoplegia and ataxia seen in the Miller Fisher and Guillain-Barré Syndromes. More recently, patients with variants of the MFS clinical triad with ophthalmoplegia, but without ataxia and areflexia have been described.
Objectives:
To report a case of acute ophthalmoplegia and mydriasis associated with IgG anti-GQ1b antibody.
Methods:
Observational case report and literature search.
Results:
A 17-year-old college student with a history of a febrile illness one month prior to presentation noted a rash involving her extremities and trunk. Within two days of the onset of the rash, she developed photophobia and paresthesias involving her extremities, and she was noted to have dilated pupils. Five days after the onset of the rash, she awakened with bilateral horizontal diplopia. Ophthalmologic examination revealed visual acuity of 20/25 in OU, bilateral dilated pupils that were nonreactive to light or accommodation, a 15 prism diopter esotropia at distance, and bilateral limitation of supraduction and abduction. The optic nerve and retina were unremarkable. Neurologic examination showed normal motor and sensory function with intact reflexes and no gait abnormalities. A work-up included a lumbar puncture, which was within normal limits and an MRI significant for incidental sinusitis. A blood test was positive for IgG and IgM against Epstein Barr viral antigens as well as for elevated GQ1b autoantibodies.
Conclusions:
The presence of a common autoantibody in MFS and GBS as well as clinical variants of the two suggests a related autoimmune etiology. This case falls along the spectrum of clinical findings associated with GQ1b antibodies and may be related to a recent infection with the Epstein-Barr virus.
A Case of Sudden Monocular Loss of Accommodation
First Author:
Mark Gans, MD, Montreal, Quebec
Abstract:
A 40-year-old male presented with sudden blurring of his OD for near and distance viewing. The visual loss was stable since its onset 4 weeks prior to presentation. There was no pain on eye movement or any other associated neurologic symptoms. He did not have any significant medical, neurologic, surgical or traumatic history. He had a pleomorphic adenoma removed from his right submaxillary gland. There was no recurrence. On examination his vision was correctable to 20/25 O.D. (-6.25 + 1.25 × 80) and 20/20 O.S. (-6.5 + 1.25 × 80). With his distance correction in place he was able to read J1+ with the OS but required a +2.5 diopter lens to read J1 print held at 30 cm with the OD. Pupils were 6mm each and both were briskly reactive to light and accommodation. The rest of the examination was within normal limits. The Humphrey 30-2 was normal in the OS and demonstrated a general reduction in the OD. An initial CT and MRI of the brain were interpreted as normal. A UBM was performed and demonstrated a 360 degree calcific band within the ciliary body of his OD. The OS demonstrated an incomplete calcific band in the ciliary body. A repeat CT of the orbit confirmed the presence of these calcifications. The patient's internist was unable to detect any calcium metabolism abnormality.
Over the ensuing months the patient's best corrected vision diminished. It became clear that he was developing a central nuclear sclerosis of his right lens. Successful cataract surgery was performed with a recovery of the patient's visual acuity. The causes of loss of accommodation will be discussed.
The Use of Contact Lenses to Treat Visually Symptomatic Nystagmus
First Author:
Valerie Biousse, MD, Atlanta, Georgia
Background:
Nystagmus degrades vision by disrupting fixation. CL may improve visual function of patients with nystagmus by 1) correcting the patient's refractive error better than spectacles; 2) by dampening the nystagmus itself through sensory feedback from movement of the CL against the cornea/lids as the eyes oscillate.
Objectives:
To determine the effects of contact lens (CL) wear on visual function of patients with visual loss from congenital nystagmus.
Methods:
4 patients with congenital nystagmus (3M, 1F, age 18-64) were included. All patients underwent complete ophthalmologic and neurologic examinations. Each patient had two evaluations separated by at least one week (one with spectacles, one with CL) including best corrected visual acuity (BCVA), contrast sensitivity, oscillopsia scale, quality of life questionnaire (NEI VFQ-25), and eye movement recording (infrared eye tracker at a sampling rate of 1000 Hz).
Results:
2 patients had congenital motor nystagmus and 2 had albinism. All had refractive errors partially corrected by spectacles and CL (BCVA: 20/40-20100). All were fitted with soft CL (diam 8.2-14.5 mm). All patients subjectively preferred CL to spectacles. Their visual acuity, contrast sensitivity, and VFQ-25 scores were improved with CL compared with spectacles alone. Eye movement recording (frequency mean, peak amplitude, peak velocity, foveation time) showed no change in 2 patients, worsening in 1 patient and improvement in 1 patient.
Conclusions:
This small sample of patients suggests that, in addition to a placebo effect from CL wear, much of the clinical improvement observed in our patients may result from a better optical correction of their refractive error with CL than with spectacles, rather than from a true dampening effect of the nystagmus by CL. More patients are currently under investigation.
Ocular Ischemic Syndrome Following Occlusion of Both External Carotid Arteries
First Author:
Adeela Alizai, MD, Ann Arbor, Michigan
Background:
Ischemic oculopathy and orbitopathy have often been reported in association with common carotid artery occlusive disease. The ischemia has been attributed to reduced flow through the internal carotid artery and its tributary, the ophthalmic artery. Yet the external carotid artery is often the principal source of blood flow to the orbit and eye. Curiously, orbito-ocular ischemic syndromes have not been reported in association with occlusion limited to the external carotid artery.
Objective:
To demonstrate the fact that isolated occlusion of both external carotid arteries can cause ischemic damage to the eye, orbit, and ocular motor nerves and to emphasize that such isolated external carotid artery occlusion may occur following carotid endarterectomy.
Methods:
Two case reports.
Results:
Case I is a 70-year-old woman who developed OS visual acuity loss, ipsilateral periocular pain, venous stasis retinopathy, iris neovascularization, and seventh nerve palsy one year after sequential carotid endarterectomies. Cerebral angiography demonstrated patent common and internal carotid arteries bilaterally, but complete occlusion of both external carotid arteries and no flow in the left ophthalmic artery. External carotid artery patch grafting and stenting restored flow through the ophthalmic artery, reversed the pain, did not reverse the ocular ischemic findings, and precipitated neovascular glaucoma. Case II is a 70-year-old man spontaneously developed right ischemic optic neuropathy, corneal edema, ipsilateral ocular motor palsies and later contralateral ischemic optic neuropathy. Cerebral angiography showed partial atherostenosis of both internal carotid arteries (right much greater than left), absent flow in the right ophthalmic artery, and bilateral external carotid artery occlusions.
Conclusions:
Bilateral external carotid occlusion, in conjunction with atherostenosis of the internal carotid artery, can cause ocular, orbital, and ocular motor ischemia. Surgeons should beware of occluding the external carotid artery during endarterectomy of the internal carotid artery.
To Sleep, Perchance to Breathe: a Case Report
First Author:
Renee Bailey, MD, San Antonio, Texas
Abstract:
A 38-year-old welder had visual loss, disc edema, and retinal hemorrhages as the presenting features of obstructive sleep apnea (OSA). General physical examination revealed height 6 feet 8 inches, weight 159 kg, BP 118/87. Ophthalmological examination demonstrated VA 20/60 OD, 20/400 OS, visual fields with enlarged blind spots with arcuate depression OU, equally reactive pupils with no afferent defect, normal ocular motility, dramatic optic disc edema, exudative maculopathy, nerve fiber layer hemorrhages on and adjacent to disc with additional pre-retinal hemorrhages. MRI and MRV of the brain were normal. CSF examination was normal with an opening pressure of 250 mm H2O. Polysomnogram performed the following night revealed repeated apneic spells and arousals every one to 2 minutes during stage 2 sleep and associated oxygen saturation between 50% and 70%. CPAP was titrated to 12 mmHg, and the patient subsequently achieved stage 4 sleep, with only 2 subsequent arousals. The patient received home CPAP and was followed for 8 months, after which time he was lost to follow-up. His final examination demonstrated VA 20/80 OD, 20/25 OS, disc edema had improved somewhat OU with resolution of hemorrhages. The maculae continued to exhibit exudative changes. OSA is a common disorder, neurologically often presenting with headache, hypertension and stroke. Although the association of OSA and disc edema has been previously described, disc edema appears to be a relatively infrequent complication. This association may be under-reported, and better data about visual loss in sleep-disordered breathing, the influence of hypertension, and identification of high-risk subpopulations are needed.
Light Sensitivity in Patients with Blepharospasm
First Author:
Wesley Adams, MD, Salt Lake City, Utah
Background:
Benign essential blepharospasm is a movement disorder characterized by excessive blinking and involuntary closure of the eyelids. That light would have something to do with blepharospasm should be expected. Patients often report their spasms to be triggered and exacerbated by light sensitivity both to ambient light and bright lights. In fact, in many series bright light is the most common exacerbating factor in almost 80%, followed by dry eye syndrome (49%), eye irritation (55%), and eye pain (31%). Some combination of these symptoms is reported in 64%. Light sensitivity has never been systematically studied in this group of patients.
Objective:
To compare light sensitivity in patients with blepharospasm, patients with known photosensitivity (migraine), and patients without blepharospasm or migraine.
Methods:
We prospectively examined 24 control patients, 30 patients with blepharospasm, and 29 patients with migraine headaches. Light sensitivity was studied by exposing patients to a bright, white, halogen light source. Luminance was measured with a portable light meter. The light was gradually increased in intensity by graduated steps until the patient reported discomfort. Each measurement was performed three times. Patients were then retested using photo-gray and FL-41 (rose-tinted) spectacles.
Results:
We found that the groups with blepharospasm and migraine both were more photosensitive than the control group. As expected, tinted spectacles increased thresholds for discomfort in all groups. Even with tinted spectacles, the migraine and blepharospasm groups were still consistently more light-sensitive than the controls. Although there was a trend for the FL-41 tint to be more effective than the photo-gray, the difference was not statistically significant.
Conclusions:
In summary, patients with blepharospasm have a lower threshold for light sensitivity than patients without blepharospasm. Light sensitivity in patients with blepharospasm is similar to that found in migraineurs. Tinted spectacles are helpful in reducing light sensitivity symptoms. We recommend that light sensitivity be addressed in patients with blepharospasm and that the clinical efficacy of tinted spectacles be studied in future investigations.
Migraine and Blood Pressure Relationships: Funduscopic Features
First Author:
Ernesto Rios-Montenegro, MD, Lima, Peru
Background:
Funduscopic features of migraine are not well defined and their correlation with blood pressure has not been established.
Objectives:
To display the funduscopic changes of different types of migraine and to show at the same time their relation to blood pressure, allowing us to infer the type and amount of ensuing hypertension.
Methods:
Observational. Fundus characteristics of classic, acephalgic and common migraine were compared during intercritic periods. Blood pressure was obtained and correlated with the funduscopic features of each type of migraine.
Results:
Classic migraine has features between those of acephalgic and common migraine. In acephalgic migraine the retinal arteries are narrow and the retinal nerve fiber layer (RNFL) has normal appearance. When these narrow arteries sclerose diastolic hypertension ensues, with a resulting short differential or pulse pressure. It corresponds to adrenergic or type A personality subjects and eventually may lead to earlier ischemic events or multiple small infarcts. On the other hand, in common migraine the retinal arteries are wide and the appearance of the RNFL is peculiarly enhanced, as manifested by accentuation of the retinal peripapillary striations. When these arteries sclerose, they lead primarily to systolic hypertension. These people have a vagotonic or type B personality and they are prone to develop large brain infarcts and hemorrhages. In classic migraine the funduscopic characteristics are indistinguishable from those of normal or non-migraine people. When their arteries harden, they more likely will develop mixed or global (systo-diastolic) hypertension.
Conclusions:
Migraine is not synonymous of headache and should not be referred only to the period of crisis. Funduscopic features during intercritical intervals allowed us to differentiate three main groups of migraine: acephalgic, classic and common. The predominant influence of adrenergic or vagotonic substances seem to be responsible for the funduscopic vascular changes as well as for the personality trait for each group of the affected individuals. Upon development of arteriolosclerosis, the appearance of the neuro-retinal vessels correlate with the type and severity of ensuing hypertension, whether primarily diastolic, systolic or systo-diastolic, as well as with the eventual development of corresponding vascular complications, particularly at the nervous and cardiac systems.
Optic Radiation Involvement in Optic Pathway Gliomas AND Neurofibromatosis
First Author:
Grant Liu, MD, Philadelphia, Pennsylvania
Background:
Optic pathway gliomas (OPG, pilocytic astrocytomas) in NF-1 typically involve some combination of the optic nerves, chiasm, or optic tracts. Involvement of the optic radiations is only rarely recognized (1).
Objective:
To report five patients with neurofibromatosis type 1 (NF-1) with gliomas involving the pregeniculate optic pathway and also the optic radiations.
Methods:
Database review of all patients with NF-1 and optic pathway gliomas seen by GTL at the Children's Hospital of Philadelphia (CHOP) from July 1993-October 2001. Patients with involvement of pregeniculate optic pathway and the optic radiations were identified. Cases were also identified from the practice of MCB at Arkansas Children's Hospital (ACH).
Results:
Four patients from CHOP (out of 83 total NF-1/OPG), and one from ACH were identified. Three had expanding mass lesions within the white matter of the temporal or parietal lobes, which were pathologically demonstrated to be pilocytic astrocytomas. The other two had radiographic involvement of the optic radiations, but did not undergo biopsy. In all five cases the vision was 20/200 or worse in OU, but the visual loss could usually be attributed to the pregeniculate involvement.
Conclusions:
Neuro-ophthalmologists should be aware that OPGs in NF-1 may involve the optic radiations, and in such patients the vision is usually severely affected. While the additional optic radiation lesions may not necessarily lead to further vision loss, the poor vision in such patients may simply reflect the relatively poorer visual prognosis of OPGs with retrochiasmal involvement in patients with NF-1 (2).
References:
1. Brown EW, Riccardi VM, Mawad M, et al. MR imaging of optic pathways in patients with neurofibromatosis. AJNR 1987; 8:1031-6.
2. Balcer LJ, Liu GT, Heller G, et al. Visual loss in children with neurofibromatosis type 1 and optic pathway gliomas: relation to tumor location by magnetic resonance imaging. Am J Ophthalmol 2001; 131:442-5.
© 2002 Lippincott Williams & Wilkins, Inc.