IN THIS ISSUE:
What Contributes to Contact Lens Discomfort?
A relatively large, very experienced study group population was fitted with one of two different hydrogel materials (comfilcon A or enfilcon A). The fit, performance, subjective comfort, and dryness were assessed upon insertion and after 3 and 6 hours of lens wear. After 6 hours, ocular surface health was also assessed by fluorescein biomicroscopy. The authors conclude that subjective dryness and discomfort after 3 and 6 hours were associated with greater lens movement, front surface deposits, poor wettability, inferior lens decentration, and Asian ethnicity. (p. 133)
Editor’s Choice open access
How do Clinicians Screen for Dry Eye?
The authors surveyed 250 exhibit hall attendees to conclude that no one test, symptom, or sign such as tear osmolarity can determine a dry eye and patients’ symptoms must remain an important element in clinical decision making. (p. 142)
Tear Breakup Times Low in Chinese Volunteers?
Our authors tried to establish the normal noninvasive tear film breakup time (NI-BUT) values in a small Chinese study group and investigate age-related changes in noninvasive tear breakup time using a newly developed keratograph (a corneal topographer with modified scan software). Perhaps because of the small sample size, the authors were unable to find differences between males and females or differences with age. Curiously, the 40 “normal” Chinese volunteers (mean age 32 ± 16.7 years) had much lower NI-BUT times than previous reports. (p. 150)
Is All Dry Eye the Same?
The study compared moderate aqueous deficient dry eye and Sjorgren’s patients inflammatory marker TNF alpha in study subjects and normals. The Sjogren’s syndrome patients demonstrated higher levels of conjunctival TNF alpha mRNA as compared to normal and moderate aqueous deficient dry eye subjects. They conclude more work is required to determine if this should “change our treatment of these patients?” (p. 156)
Viability of a Commercial Warm Compress for the Eye
A commercially available warm compress device significantly increased the lipid layer thickness and tear breakup time immediately following treatment in a group of 22 healthy participants. Even 10 minutes after treatment, these measurements were higher than in controls. The authors conclude that, after future long-term clinical efficacy and safety studies, the MGDRx EyeBag may be a simple device for heating the eyelids to increase tear breakup and lipid layer thickness in meibomian gland dysfunction (MGD). (p. 163)
Caffeine and Tear Secretion?
Caffeine, regarded as the most widely consumed psychoactive substance in the world, is claimed to affect the eye’s tear film and function. In view of the high prevalence of dry eye seen clinically and the challenges associated with dry eye management, the authors studied the effect of orally ingested caffeine on tear secretion in healthy non–dry-eye participants. They found that caffeine appears to stimulate tear secretion. They urge others, in other countries, to also study the effect of caffeine on tears, given the potential implications for aggravating the high prevalence of dry eye symptoms seen clinically. (p. 171)
Corneal Changes after Crosslinking for Progressive Keratoconus
Here, topographic analysis demonstrated corneal crosslinking (CXL) as a potent treatment modality for temporarily halting corneal ectasia progression in keratoconus eyes. The coexistent increase in the elevation data derived from the posterior corneal surface might indicate an ongoing ectatic process within the posterior part of the cornea, despite the stabilized anterior surface. With follow-up after CXL, the authors conclude that corneal topography is superior to corneal tomography with the significant changes detectable using topographic analysis and because of the potential methodological errors when using optical corneal tomography after CXL. (p. 178)
Glaucomatous Visual Field Loss Encourages Being Home-Bound
The authors used a new cellular tracking device to conclude that glaucoma patients with severe visual field loss have fewer excursions away from home than glaucoma suspects. This conclusion has implications for patient management because being confined to the home environment may have detrimental effects on fitness and health. To encourage safe travel away from home, glaucoma patients should be encouraged to have orientation and mobility training. (p. 187)
Proliferative Diabetic Retinopathy Vision Loss Involves Neural Blur
The authors investigated the relative contributions of optical and neural sources of intrinsic blur to visual acuity deficits in patients with proliferative diabetic retinopathy. Patients with visual acuity deficits had abnormally high levels of intrinsic blur that were generated by non-optical sources, suggesting that neural blur is an important factor that limits visual acuity in these patients. (p. 194)
College Baseball Players Keep their Eye on the Ball but Track Pitches with their Head
Our authors developed a method to estimate horizontal eye gaze tracking errors as participants viewed a large number of pitched tennis balls. They assessed horizontal eye, head, and tracking strategies of a group of Division 1 college baseball players. Their participants viewed the pitch but did not swing a bat. All were asked to call the color (black or red) and number on the balls while eye and head movements were monitored with a video eyetracker and an inertial sensor. These movements were synchronized with ball position. On average, college players tracked the pitched ball primarily with the head and maintained gaze close to the ball throughout much of the trajectory; the eyes moved very little until late in the pitch trajectory. (p. 200)
Under-Correction of Refractive Error a Problem Among Asian Ethnicities
A large Singapore population-based study of over 10,000 Asians participants of different ethnicities revealed that ethnic variations existed in the prevalence of under-corrected refractive error but not in its impact on vision-specific functioning. The authors suggest the data could assist in targeting education and appropriate referral by health care providers. (p. 212)
Reconciling Subjective Refraction and Optical Aberration Measures
In some eyes, aberrometric measurements of the refractive error can differ by more than 1 D from standard subjective refraction. The authors set out to understand the reasons for these discrepancies by looking at outliers (>1.0 D discrepancy). They noted that by the Stiles-Crawford effect (inhomogeneous pupil transmission) and irregular pupil shape, they were able to reconcile the discrepancies and propose a novel “generalized refractive error sensing” method to provide reliable clinical refractive error measures. (p. 221)
Surgery Impact on Axial length Progression?
In myopia, biometry including the axial length is important along with the refractive data. The authors compared the rates of myopic regression in two highly myopic Japanese groups matched for age, axial length, and preoperative refractive error. Three years after either phakic intraocular lens implantation or LASIK, there were differences in axial length progression in these two groups. The LASIK group had significantly greater progression of axial length, raising interesting questions regarding myopia progression. (p. 231)
Chromatic Aberration of Pseudophakic Eyes
The authors’ study used a series of different IOL implants to determine that intraocular lenses do “not always” increase the chromatic aberration of the eye when compared to an unaccommodated normal eye. (p. 240)
A Challenging IOL Power Calculation
In the presence of corneal scars, with undetectable keratometric (K) readings, calculating the power of the needed IOL is difficult. The authors apply a new method to calculate the IOL power. (p. e29)
An Important Differential Diagnosis of Rare Sclerochoroidal Calcification
The fundus presentation of sclerochoroidal calcification, characterized by multifocal, yellow-white elevated fundus lesions, can be confused for an intraocular malignancy or choroidal osteoma, and can have vision-threatening complications, such as choroidal neovascular membrane or serous detachment. The visual prognosis for sclerochoroidal classification is good, as the lesions are typically located away from the macula and foveal encroachment is rare. (p. e32)
Conjunctival Metastasis and Stage IV Lung Cancer
The authors present an extremely challenging case of a lung cancer that had multiple metastases, including to the palpebral conjunctiva. Conjunctival metastasis of non–small cell lung cancer (NSCLC) is rare. It can be difficult to clinically differentiate eyelid tumors as benign or malignant by examination alone. A thorough history and clinical examination raised concerns of a malignant neoplasm, either as a primary or metastatic lesion. Timely and appropriate referral, biopsy, and imaging were needed to obtain a precise diagnosis and staging of the disease. (p. e38)
Purtscher’s Retinopathy Secondary to Acute Pancreatitis
The authors highlight a case of Purtscher’s retinopathy, a rare ocular disease not typically seen in optometry. It tends to be associated with significant trauma, but can be secondary to various systemic conditions, such as acute pancreatitis. Emphasis tends to be on the underlying disease or trauma; however, changes to vision may also occur and necessitate an eye examination in all cases. Our authors review the current literature on the disease and its pathophysiology because there is limited information and research on Purtscher’s retinopathy. (p. e43)