Cystoid Macular Edema in the Non-Infectious Necroinflammation Phase of Acute Retinal Necrosis

Purpose To explore the clinical characteristics of the cystoid macular edema (CME) during the non-infectious chronic necroinflammatory phase in acute retinal necrosis (ARN).Methods A retrospective cohort study. Viral load dynamics were assessed after initiation of antiviral therapy. Patients were followed up for the development of CME, and the clinical characteristics were compared between patients with and without developing CME.Results A total of 35 eyes of 32 patients with ARN were included. Viral load in the aqueous humor became undetectable after a mean of 55.13 ± 21.90 days after antiviral therapy. After a median of 4.93 months after initial diagnosis, CME developed in 55.9% of eyes. The risk of developing CME was significantly higher in patients with delayed antiviral treatment (>2 weeks from initial diagnosis) (p = 0.023). In addition, patients with delayed systemic steroid use (>1 week after antiviral therapy) (p = 0.046) were also more likely to develop CME in non-infectious chronic necroinflammation phase of ARN.Conclusions CME is prevalent in the chronic necroinflammation phase of ARN. Timely antiviral and steroid therapy are pivotal in mitigating CME development and preserving visual outcomes during this phase.