A 67-year-old woman presented with delayed-onset bilateral nonarteritic ischemic optic neuropathy (NAION) after immediate sequential bilateral cataract surgery (ISBCS) performed on the same day under general anesthesia. This was a devastating outcome for the patient and led to severe visual impairment. To our knowledge, this is the first report of delayed-onset bilateral NAION after bilateral immediate sequential cataract surgery performed under general anesthesia.
A 67-year-old woman with a medical history of hypertension and hyperlipidemia underwent ISBCS (phacoemulsification with intraocular lens implantation) on the same day under general anesthesia. Both surgeries were uneventful phacoemulsification surgeries performed back-to-back. The patient presented 5 months later with right eye blurring of vision. On examination, she was found to have bilateral disc swelling, with the right disc more swollen than the left, and the macula was dry (Figure 1). Her visual acuity (VA) was 3/60 in her right eye and 6/9 in her left eye on first presentation; however, the left eye VA deteriorated within 1 week to 6/60. Visual field examination was performed by confrontation at the time and showed left central field defect and right inferotemporal quadrant field defect with enlarged blind spot. The patient could not cooperate well for formal visual field assessment. Optical coherence tomography examination of the retinal nerve fiber layer demonstrated bilateral nerve fiber layer edema.
Investigations were performed to rule out other causes; magnetic resonance imaging of the brain and orbits showed no enhancing lesions along the optic nerve but mild small vessel disease in the brain. Blood investigations included C-reactive protein, platelet count, and erythrocyte sedimentation rates. Neuromyelitis optica antibody levels were normal. Lumbar puncture was performed for the patient, which showed normal opening and closing pressure. Contrast sensitivity function cytology was unremarkable. The patient did not have any headache or scalp pain, and temporal pulses were present. There was low clinical evidence of giant cell arteritis in this patient; therefore, temporal artery biopsy was not performed.
As a diagnosis of exclusion, the patient was diagnosed with bilateral NAION. This occurred within 5 months of her ISBCS. The patient was given a trial course of intravenous steroid therapy (methylprednisolone 250 mg every 6 hours for 3 days). The patient was discharged with a tapering dose of oral prednisolone. On outpatient follow-up 2 weeks later, her right eye VA improved slightly to 6/24, but her left eye VA remained the same at 6/60. The patient started antiplatelet therapy (Plavix, because she was allergic to aspirin) as prevention for further vascular morbidity. The patient received follow-up care for more than 6 weeks, and her VA was stable with no further recovery. Both discs showed slight blurring of nasal disc margins, and there was mild left disc pallor.
Although NAION has long been reported to have possible association with cataract surgery, there is controversial evidence for a causal relationship, with some studies suggesting a unique increased risk after cataract surgery and others showing similar incidence to the general population.1,2 Although a definite causal relationship is difficult to prove, some reports suggest that cataract extraction adds a unique risk factor. For example, reported incidence of delayed NAION after cataract extraction is 1 in 2000, which is significantly higher than the incidence of NAION in the general population (2.3–10.3 in 100 000).1 Reports of NAION occurring within 3 to 5 weeks after cataract surgery in each respective eye also point more toward a temporal relationship.3
Interestingly, the usual risk factors for NAION, such as hypertension and presence of a crowded disc, were found to be less common in patients who suffered from NAION post cataract extraction.4 Similarly, cataract surgery was found to increase risk of NAION, independent of medical risk factors, suggesting a different pathophysiology.5
Cases of bilateral NAION occurring after bilateral cataract extraction are rarely reported, and in this study, to our knowledge, we report the first-documented case of simultaneous bilateral NAION occurring after ISBCS under general anesthesia. Our case was reported 5 months after the bilateral cataract surgery; therefore, it might be classified as a delayed-onset post cataract extraction NAION. In the current literature, most cases of post cataract extraction NAION occur within 6 months postoperatively, and most of these cases are a delayed-onset type—meaning that the event occurs within days to weeks postoperatively.6
There are 4 reported cases in the current literature showing sequential bilateral NAION post cataract surgery in each respective eye. All cases were performed under local anesthesia, and the cataract extractions were not performed on the same dates. The bilateral NAION occurred in these patients ranging from weeks to months after the respective cataract surgeries, and both eyes did not develop NAION at the same time.3,7,8 There is considerable difference between these reported cases and this case report because, in our case, surgery was performed under general anesthesia, and both surgeries were done back-to-back on the same day. NAION in our case occurred at the same time in both eyes.
General anesthesia itself might be a risk factor for NAION. NAION has also been found to be associated with nonocular surgeries performed under general anesthesia such as spinal, cardiovascular, and orthopedic surgeries. Apart from excessive hemorrhage and prone position, prolonged hypotension is a risk factor of development of NAION in such surgeries.9 For example, a case of unilateral NAION was reported 2 days post uneventful strabismus surgery in the same eye. The surgery was performed under general anesthesia, and the NAION was attributed to the perioperative hypotension.10 However, it is important to note that, in that case, both eyes were exposed to the systemic hypotension yet NAION developed only in the operated eye. Both general anesthesia and surgery might have contributed to the NAION occurrence.
ISBCS is becoming more increasingly performed worldwide and might be a cost-effective solution to meet the demands of an aging population. In a recent report from Royal College's National Ophthalmology Database study, most ISBCSs were performed under general anesthesia.11 ISBCS might be preferred in patients who require general anesthesia because it prevents them having to undergo general anesthesia twice. However, there are still concerns of bilateral serious complications such as postoperative endophthalmitis, although the risk is very low. Our case has highlighted another possible risk: simultaneous bilateral NAION post cataract surgery, especially if performed under general anesthesia in patients with preexisting vascular risk factors. This is perhaps another risk that should be explained to the patient if they are to undergo ISBCS under general anesthesia.
Regarding treatment of NAION, there is no strong evidence to suggest that steroid therapy is effective, although trial of steroids is given by many physicians based on anecdotal evidence.12 Our case showed slight improvement of VA in her right eye after steroid therapy, but it is not known whether this improvement would have occurred spontaneously. The VA of her left eye did not improve. There is currently no proven effective treatment option or prophylaxis for NAION. Other possible therapies such as with hyperbaric oxygen, neurotrophic therapy, levodopa, and optic nerve sheath decompression have been suggested, but further studies are needed to determine efficacy.13 Use of aspirin and antiplatelet therapy might have been useful in prevention of sequential NAION in the fellow eye.14
In summary, this is the first-reported case of delayed-onset bilateral NAION after ISBCS performed under general anesthesia, to our knowledge. With increasing ISBCS being performed, bilateral NAION is a delayed complication that can be devastating. Awareness needs to be raised on this potential complication, and we would recommend it to be advised to patients alongside the other well-known risks.
WHAT WAS KNOWN
- No cases of bilateral nonarteritic ischemic optic neuropathy occurring after immediate sequential bilateral cataract surgery under general anesthesia have been reported.
WHAT THIS PAPER ADDS
- Bilateral nonarteritic ischemic optic neuropathy can occur after immediate sequential bilateral cataract surgery performed under general anesthesia.
1. McCulley T, Lam B, Feuer W. Incidence of nonarteritic anterior ischemic optic neuropathy associated with cataract extraction. Ophthalmology 2001;108:1275–1278
2. Moradi A, Kanagalingam S, Diener-West M, Miller N. Post–cataract surgery optic neuropathy: prevalence, incidence, temporal relationship, and fellow eye involvement. Am J Ophthalmol 2017;175:183–193
3. Bénard-Séguin É, Weisbrod L, Sundaram A. Silent post cataract bilateral sequential nonarteritic anterior ischaemic optic neuropathy. Neuroophthalmology 2019;43:318–322
4. McCulley T, Lam B, Feuer W. A comparison of risk factors for postoperative and spontaneous nonarteritic anterior ischemic optic neuropathy. J Neuroophthalmology 2005;25:22–24
5. Al-Madani M, Al-Raqqad N, Al-Fgarra N, Al-Thawaby A, Jaafar A. The risk of ischemic optic neuropathy post phacoemulsification cataract surgery. Pan Afr Med J 2017;28:53
6. Lam B, Jabaly-Habib H, Al-Sheikh N, Pezda M, Guirgis M, Feuer W, McCulley TJ. Risk of non-arteritic anterior ischaemic optic neuropathy (NAION) after cataract extraction in the fellow eye of patients with prior unilateral NAION. Br J Ophthalmol 2007;91:585–587
7. Barequet D, Moisseiev E, Michaeli A, Dotan G. Bilateral sequential NAION following cataract extraction: case report and review of the literature. Case Rep Ophthalmol 2014;5:292–296
8. Nguyen L, Taravella M, Pelak V. Determining whether delayed nonarteritic ischemic optic neuropathy associated with cataract extraction is a true entity. J Cataract Refract Surg 2006;32:2105-2109
9. Berg KT, Harrison AR, Lee MS. Perioperative visual loss in ocular and nonocular surgery. Clin Ophthalmol 2010;4:531-546
10. Tsagkataki M, Rowlands A. Visual loss due to non-arteritic anterior ischemic optic neuropathy (NAION) immediately following routine strabismus surgery under general anesthesia—a case report. Strabismus 2012;20:121–123
11. Buchan J, Donachie P, Cassels-Brown A, Liu C, Pyott A, Yip JLY, Zarei-Ghanavati M, Sparrow JM. The Royal College of Ophthalmologists' National Ophthalmology Database study of cataract surgery: report 7, immediate sequential bilateral cataract surgery in the UK: current practice and patient selection. Eye January 7, 2020 (https://www.nature.com/articles/s41433-019-0761-z
) Accessed May 26, 2020.
12. Chen J, Zhu J, Chen L, Hu C, Du Y. Steroids in the treatment of nonarteritic anterior ischemic optic neuropathy. Medicine 2019;98:e17861
13. Arnold A, Levin L. Treatment of ischemic optic neuropathy. Semin Ophthalmol 2002;17:39–46
14. Atkins EJ, Bruce BB, Newman NJ, Biousse V. Treatment of nonarteritic anterior ischemic optic neuropathy. Surv Ophthalmol 2010;55:47–63