Coronaviruses, belonging to the RNA virus family, can cause infections in both humans and animals. Coronavirus disease is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease caused by this virus was named COVID-19, where “CO” stands for corona, “VI” for virus, “D” for disease, and “19” indicates the year in which it occurred. COVID-19 is a systemic disease affecting the whole body and manifesting with the general findings of fever, cough, fatigue, headache, sore throat, loss of taste, loss of smell, and low back pain [1], [2]. In this disease, ocular findings can also be seen and sometimes even present as initial findings. Ocular findings associated with COVID-19 include eye watering, itching, foreign body sensation, double vision, blurred vision, limitation of eye movements, conjunctivitis, Guillain-Barré syndrome, chemosis, lagophthalmos and ischemic optic neuropathy [3], [4].

Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality that has recently been used to visualize retinal vascular blood flow. OCTA can measure both the superficial and deep vessel densities in the macular capillary plexus by detecting motion contrast in blood flow [5]. In previous studies, retinal and choroidal vascular density values in patients with COVID-19 were compared with control groups using OCTA, and statistically significant results were obtained [6], [7]. The current study aimed to compare the retinal, choroidal and optic disc vascular density values, choroidal thickness, and retinal nerve fiber layer (RNFL) thickness of the same individuals before and after COVID-19 using the OCTA device. We conducted this study with the hypothesis that changes in the posterior segment structures and posterior segment vascular density caused by COVID-19 can be detected using the OCTA device.