Factors at the initial visit associated with poor visual outcomes in patients with acute retinal necrosis

Background/Objective: Acute retinal necrosis (ARN) is a vision-threatening disease caused by herpesvirus infection. This study aimed to investigate the visual prognostic factors that could be determined at the initial visit. Subjects and Methods: This retrospective study included 34 patients with ARN. Logistic regression analysis was employed to evaluate the associations between poor final visual outcomes and various factors, including poor initial visual acuity, presence of retinal detachment at the initial visit, posterior extension of necrotizing retinitis, and circumferential extension of necrotizing retinitis. Posterior extension was evaluated with three zonings, from the periphery (zone 3), mid-periphery (zone 2), and macula (zone 1). Circumferential extension was evaluated according to the degree of necrotizing retinitis lesions using ultra-wide fundus imaging. Results: The mean logarithm of the minimum angle of resolution was 0.63 ± 0.68 at the initial visit and 0.83 ± 0.65 at 12 months after the initial visit. Seven patients had a retinal detachment. The distribution of posterior extension at the initial visit was 5 in zone 1, 20 in zone 2, and 9 in zone 3. The average of necrotizing retinitis lesion angle was 249 ± 115°. The logistic regression analysis revealed that participants with wide angles of necrotizing retinitis were associated with final poor vision, with an odds ratio of 1.28 per 30° increase (95%CI: 1.00–1.65, p = 0.03). Conclusions: Assessment of the widespread circumferential extension of white necrotizing retinal lesions at the initial visit is a crucial risk factor for the visual prognosis in ARN.