Macular Perfusion Changes in People Administered Two Different Types of COVID-19 Vaccines: An Optical Coherence Tomography Angiography Study

Background: Pfizer-BioNTech COVID-19 Vaccine and other COVID-19 vaccines produced by different mechanisms have been developed and administered to people globally to combat the acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although rare ocular thrombotic and ischemic side effects have been reported from the vaccination, the pathophysiology is still unclear.Methods: In this prospective cohort study, individuals who received two doses of inactivated COVID-19 vaccine and one dose of mRNA vaccine were examined before and after each vaccine dose. Systemically or ophthalmologically healthy subjects were included in the study. Complete ophthalmologic examination and macular imaging with Optical Coherence Tomography Angiography (OCTA) were performed during each visit. sCVD and dCVD (foveal, parafoveal, perifoveal areas), foveal avascular zone (FAZ), and values of choriocapillaris flow (central 1 mm and 6 mm diameter areas) were examined.Results: Twenty-four eyes of 24 subjects were included in the study. A significant decrease was observed in the sCVD in the parafoveal area after the second dose of the CoronaVac vaccine compared with the measurement after the first dose. In the dCVD, vascular attenuation was observed only in the parafoveal region after the first dose of the CoronaVac vaccine. However, a significant decrease was observed in all regions of the dCVD and subfoveal choriocapillaris flow after the second dose. A significant decrease was observed in the sCVD and the dCVD, subfoveal choriocapillaris flow of most regions after BNT162b2 compared with the measurement with a no-vaccination period.Conclusion: Vascular attenuation observed in some areas, particularly after the second dose of the CoronaVac vaccine, may explain the pathogenesis of postvaccine ocular ischemic pathologies reported in the literature. However, these pathologies are extremely rare, and the incidence of thrombotic events caused by the COVID-19 infection is higher.