Purpose: Non-arteritic anterior ischemic optic neuropathy (NAION) is an ischemic disorder of the optic nerve head often associated with systemic vascular risk factors. While COVID-19 is primarily a respiratory disease, it has been linked to vascular and thromboembolic complications. This study compared the incidence, clinical characteristics, and outcomes of NAION diagnosed before and during the COVID-19 pandemic. Patients and Methods: A retrospective review was conducted of new NAION cases at a tertiary neuro-ophthalmology clinic diagnosed between May 2017–May 2019 (Pre-COVID) and March 2020–March 2022 (During-COVID). Data collected included demographics, vascular risk factors, clinical presentation, visual acuity, optical coherence tomography–derived retinal nerve fiber layer (RNFL) thickness, and visual field mean deviation (VF MD). Statistical analyses employed Chi-square, Fisher’s exact test, t -test, and Mann–Whitney U -test. Results: Among 1,543 clinic patients, 46 were diagnosed with NAION (Pre-COVID: 27; During-COVID: 19). The relative frequency of NAION increased during the pandemic (3.7% vs 2.6%). Patients in the During-COVID group had significantly higher rates of hypertension (84.2% vs 40.7%, p=0.003), atherosclerotic cardiovascular disease (15.8% vs 0%, p=0.033), suspected sleep apnea (36.8% vs 0%, p=0.001), obesity (21.1% vs 0%, p=0.013), and smoking history (42.1% vs 3.7%, p=0.001). Subacute onset was more frequent during the pandemic (36.8% vs 0%, p=0.001), suggesting delayed presentation. At three months, visual acuity was worse in the During-COVID group (logMAR 1.34 vs 0.72, p=0.014). Baseline RNFL thickness and VF MD did not differ significantly. Only 31.6% of During-COVID cases had documented SARS-CoV-2 infection. Conclusion: During the COVID-19 period, NAION was proportionally more frequent and associated with increased vascular comorbidities, delayed presentation, and worse visual outcomes. Both direct viral and indirect pandemic-related factors may contribute. Keywords: COVID-19, NAION, SARS-CoV-2 infection, optic nerve ischemia, visual outcome
Chaitanuwong et al. (Thu,) studied this question.