Eyeworld

31 EW FEATURE June 2018 • Neuro-ophthalmology for the anterior segment surgeon On the other hand Not all surgeons are convinced that the risk of NAION after cataract surgery is as low as this study found. In an editorial published in the same journal issue as the study, Timothy McCulley, MD, associate professor of ophthalmology, Wilmer Eye Insti- tute, Johns Hopkins School of Med- icine, Byron Lam, MD, professor, Bascom Palmer Eye Institute, Uni- versity of Miami School of Medicine, Miami, and William Feuer, MD, Bascom Palmer Eye Institute, shared their thoughts about the NAION study. 2 They pointed out the study's use of only one diagnostic code to identify NAION and a small sample size with a very large confidence interval. "The hazard in underesti- mating the risk of NAION associated with cataract surgery lies in the second-eye involvement. …With the potential devastating consequence of bilateral NAION, proceeding with caution when considering cataract extraction in patients with a history of NAION seems prudent and appro- priate," the editorial authors wrote. The editorial authors do think that the risk of NAION has likely decreased with modern cataract sur- gery techniques, just not as much as the study identified. Take-home pearls What should cataract surgeons and neuro-ophthalmologists advise pa- tients regarding the risk of NAION after cataract surgery? EyeWorld asked a few of the authors from the study and the editorial to share their take-home message. Here's what they shared. "I used to tell patients who had post-cataract NAION in one eye that they had a 50% risk of developing a similar event in the other eye and that they should not undergo cataract surgery unless they were truly unable to perform their daily activities because of poor vision in the second eye," Dr. Miller said. "I now tell them that we used to think this was the case, but that I do not think this is the case any longer. I also tell them that if they do un- dergo cataract surgery, they should have it performed under topical anesthesia." Ahmadreza Moradi, MD, Mount Sinai Health System, New York, an author of the NAION study, said, "Our study could not support the idea that patients who have experienced NAION in one eye have an increased risk of NAION follow- ing non-complex cataract surgery in the fellow eye." "I have no doubt cataract sur- gery or other intraocular procedures can be a trigger factor for NAION," Dr. Lam said. "This is particularly true when the surgical procedures are complicated by surgical trauma and increased intraocular pressure. … If a patient has NAION in one eye, I would defer cataract ex- traction in the fellow eye until the cataract has a notable impact on activities of daily living." "Where it becomes important is if there is a history of [ischemic optic neuropathy] in one eye, whether it's associated with cataract surgery or not, and then having cataract surgery in the other eye," Dr. McCulley said. "Three points of advice: (1) Make efforts to not have a pressure spike to trigger optic neu- ropathy. (2) Do whatever you can to control inflammation. Work with a seasoned surgeon. (3) If the patient is borderline on the cataract's visual impact, wait till the patient really needs it, until there is more substan- tial visual compromise." EW References 1. Moradi A, et al. Post-cataract surgery optic neuropathy: Prevalence, incidence, temporal relationship, and fellow eye involvement. Am J Ophthalmol. 2017;175:183–193. 2. McCulley TJ. Nonarteritic anterior ischemic optic neuropathy and intraocular surgery. Am J Ophthalmol. 2017;175:xiv–xvi. Editors' note: The physicians have no financial interests related to their comments. Contact information Lam: blam@med.miami.edu McCulley: tmccull5@jhmi.edu Miller: nrmiller@jhmi.edu Moradi: ahmadreza.moradi1@gmail.com Fundus of a patient with NAION The fellow eye Source: Neil Miller, MD

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