Comparison of optic nerve head and macular perfusion changes before and after the development of COVID-19.

BACKGROUND: COVID-19 is known to induce systemic endothelial inflammation and microvascular dysfunction, with reported implications for various tissues, including ocular structures. Optical coherence tomography angiography (OCTA) offers a non-invasive and high-resolution method to visualize and quantify retinal microcirculatory networks. While prior research has investigated ocular microvascular changes in COVID-19 patients, studies comparing these alterations in the same individuals before and after infection are limited. METHODS: Among individuals who had baseline OCTA at their previous admission to our clinic, 20 patients who later contracted and recovered from COVID-19 were included in the study. OCTA images were obtained using the AngioVue optical coherence tomography angiography system, with split-spectrum amplitude decorrelation angiography images. After resolution of COVID-19, OCTA was performed again in these patients, and the results were compared with the previous foveal avascular zone (FAZ) and vessel densities (VD) findings. RESULTS: After disease resolution, the optic nerve head vessel density (ONH-VD) was found to be statistically significantly decreased in all areas except the superonasal area, while the radial peripapillary capillary vessel density (RPC-VD) was found to be statistically significantly decreased in all areas, except inside the disc and superonasal and temporal areas. The superficial capillary plexus vessel density (SCP-VD) was found to be significantly decreased in the superior hemi, superior and nasal areas, and the deep capillary plexus vessel density (DCP-VD) significantly decreased in the whole image, parafovea, and inferior hemi and inferior and nasal areas. CONCLUSIONS: After resolution of COVID-19, the ONH-VD and RPC-VD decreased generally, and in the macular region, the SCP-VD and DCP-VD decreased in certain areas. These results may be important in understanding the effects of COVID-19 on systemic vascular circulation.