Difference in Optical Coherence Tomography Angiography Parameters After SARS-CoV-2 Infection During the Alpha and Delta Variant Dominance Periods

The SARS-CoV-2 infection manifests with diverse clinical manifestations, with severity potentially influenced by the viral variant. COVID-19 has also been shown to impact ocular microcirculation in some patients, but whether this effect varies by viral lineage remains unclear. This prospective study compared clinical features and ocular parameters assessed via optical coherence tomography angiography (OCTA) in patients recovering from SARS-CoV-2 infections during the dominance of two distinctive viral lineages, Alpha (B.1.1.7) and Delta (B.1.617.2), and compared them to a control group. The following parameters were measured: vessel density (VD) in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CCP) using OCTA, with a manual assessment of the foveal avascular zones in the SCP (FAZs) and DCP (FAZd). A control group was also included. Among 63 patients in the Alpha group and 41 in the Delta group, no eye-related symptoms were reported during the examination. However, the Delta group showed significantly lower VD in the SCP and DCP across all quadrants (<i>p</i> < 0.001-0.039), while the Alpha group showed reduced VD in the foveal CCP (<i>p</i> = 0.005) and significantly wider FAZs and FAZd (<i>p</i> = 0.002 for both). In conclusion, ocular microcirculatory changes differed between the two variants, with Alpha associated with foveal choroidal VD reduction and larger FAZs and Delta linked to lower SCP and DCP VD across multiple regions. These findings highlight the potential for SARS-CoV-2 variants to differentially impact ocular vasculature, underscoring the need for variant-specific follow-up in COVID-19 patients.