Background Due to the emergence of COVID-19, many countries have started mass immunization programs. To date, no cases of optic neuritis following COVID-19 vaccination have been reported in the literature. Case presentation Objective: Here, we report 2 cases of unilateral optic neuritis after vaccination against COVID-19 using the Sinopharm vaccine (Sinopharm Group Co. Ltd, China). Design The clinical history, examination, and test findings of two individuals with unilateral optic neuritis associated with the timing of COVID-19 vaccination were described and further analyzed. Setting Two patients developed optic neuritis after receiving the COVID-19 vaccine. One patient developed optic neuritis 6 weeks after the first dose and 3 weeks after the second dose. The other patient developed optic neuritis 3 weeks after the first dose. Participants: Two female patients, aged 21 and 39 years. Result The patients were successfully treated with intravenous methylprednisolone pulse therapy. Both patients had typical manifestations of optic neuritis and their visual acuity recovered fully after treatment. The second of these patients was positive for anti-myelin oligodendrocyte glycoprotein antibodies (MOG). Conclusion Optic neuritis is a potential adverse effect after vaccination against the coronavirus disease (COVID-19). Supplementary Information The online version contains supplementary material available at 10.1007/s10633-022-09880-0.

Introduction: Hypertension is known to impact the structure and function of the ocular vascular system and is an established risk factor for many eye diseases. This study aimed to detect the blood flow in the optic disc and macula in patients with essential hypertension and to analyze its correlation with serum cystatin C (Cys-C) levels. Methods: This single center, cross-sectional study included 100 patients with primary hypertension without hypertensive retinopathy, who were divided into an experimental group (50 cases, 50 eyes) with elevated serum Cys-C levels and a control group (50 cases, 50 eyes) with normal serum Cys-C . The optic disc and macular vessel density (VD) and vascular perfusion density (PD) were assessed using optical coherence tomography angiography (OCTA). Data such as the area, perimeter, and circularity of the foveal avascular zone (FAZ) were analyzed. Results: There were statistically significant between-group differences in the VD and PD of the optic disc (P<0.05). Spearman correlation analysis of related indicators revealed that serum Cys-C was positively correlated with creatinine, uric acid, and FAZ circularity (P<0.05). Furthermore, serum Cys-C was negatively correlated with optic disc VD and PD in some regions(P<0.05). Conclusion: In patients with essential hypertension, serum Cys-C is negatively correlated with VD and PD in the inner layer of the optic disc (zone 10).