Branch Retinal Vein Occlusion after Messenger RNA-Based COVID-19 Vaccine.

Two days after the second dose of the messenger RNA-based COVID-19 vaccine (BNT162b2), a healthy 38-year-old man developed branch retinal vein occlusion (BRVO) in his left eye (OS). His previous medical history was unremarkable and he was a nonsmoker. His blood pressure was 117/78 mm Hg. Blood examination did not suggest thrombophilia. His best-corrected visual acuity (BCVA) was 0.9 OS with myopic correction. A fundus examination showed a retinal hemorrhage and cotton wool spots in the superotemporal region of the posterior pole OS. Optical coherence tomography macular scans showed subfoveal fluid accumulation and retinal thickening in the superior macular region OS. Two intravitreal injections of aflibercept were administered 2 months apart. By 7 months after the initial visit, the BCVA was 1.2 OS and the retinal hemorrhage and macular edema have resolved. BRVO can be seen after BNT162b2 vaccinations. Because the third doses of the vaccine are beginning to be administered more widely, ocular complications including RVO can develop and require attention.