1198 Acute Onset Vision Loss in a Patient with NAION and OSA

Introduction Non-arteritic anterior ischemic optic neuropathy (NAION) is the most common optic neuropathy in middle-aged and older-aged adult. There are an estimated 6000 new cases per year and is most commonly diagnosed in patients between 61-72 years of age. It affects men and women equally. There is a slightly higher incidence in white patients. 55-59% of patients with NAION also have OSA. Report of case(s) A 51-year-old man with a past medical history of hypertension and erectile dysfunction developed painless left inferior altitudinal visual field loss and blurriness in April 2023. He was seen in the Ophthalmology Department and was found to have left unilateral optic disc swelling on fundoscopic examination. An MRI of his brain, orbits, and face were normal. He was referred to Neuro-Ophthalmology where a slit lamp and fundus exam was performed and was significant for 360 degrees of disc swelling with heme seen inferiorly and normal appearing vessels and macula. A follow up fundoscopic examination one month later was significant for a hyperemic nerve and nasal blurriness in the left eye. No changes were seen in the right eye. Based on these findings, he was diagnosed with NAION. A HST was ordered by his Ophthalmologist that showed moderate OSA with an AHI of 24.3/h, an O2 nadir of 81%, and an ODI of 32.3. He was then seen in the Sleep Medicine clinic and prescribed CPAP. At his two month follow up appointment, he had an improvement in his daytime sleepiness and concentration but still had residual visual deficits in his left eye, including blurriness, light sensitivity, and difficulty focusing. Conclusion NAION is a rare condition with untreated OSA as a known risk factor due to nocturnal hypoxia decreasing perfusion to the optic nerve. This case reinforces the notion that the hypoxic burden of untreated OSA is a systemic problem and can lead to damage throughout the body. In this case, the benefit of treating this patient’s OSA is that his contralateral eye, the right eye, is also vulnerable to developing the same ischemic optic neuropathy that the left eye suffered from. Support (if any)