Retinal Vascular Occlusion and SARS-CoV-2 Vaccination

Abstract Purpose: to assess the clinical and retinal imaging features of patients in whom retinal vascular occlusion had developed in temporal associations with Covid-19 vaccination.Methods: in this retrospective case series, all consecutive adult patients with new onset retinal vascular occlusion (VO) within 6 weeks of vaccination against Covid-19 were included in the study between May 1st and October 31st 2021. All patients had a systemic medical health assessment, full ophthalmic evaluation and complete fundus imaging. Results: Fifteen cases of retinal vascular occlusion (14 patients) after Covid-19 vaccinations were identified. The median time between vaccination and symptoms onset was 14 days (range 7-42 days). VO included central retinal vein occlusion (CRVO) in 5 (33.3%) eyes, hemiretinal vein occlusion (HRVO) in 2 (13.3%) eyes, branch retinal vein occlusion (BRVO) in 7 (46.6%) eyes, and 1 (6.6%) eye with central retinal artery occlusion (CRAO). The mean BCVA was 20/55 with a range of 20/20 to 20/200. Eleven of 15 eyes (73.3%) had visual acuity improvement after intravitreal treatment at 60-90 days (range, 45-105 days) from the presentation. Number of new cases of VO was higher in the considered period compared to the equivalent 6 months’ period in 2019 (1.17% vs 0.52% respectively; P=0.0134).Conclusions: Retinal vascular occlusion with different grades of severity are reported in temporal association with Covid-19 vaccination. Prompt diagnosis with appropriate treatment may provide patients with better visual acuity outcome. The exact pathogenic mechanism needs to be further studied. No certain causal relationship can be established from this case series.