Assessment of alterations in the retina and vitreous in pre- and post-COVID-19 patients using swept-source optical coherence tomography and angiography: A comparative study.

Ocular manifestations have been well recognized in coronavirus disease 2019 (COVID-19) outbreak. Several studies have detected ocular manifestations in patients after COVID-19. However, little is known about the retinal and vitreal alterations in patients before and after COVID-19 infection. This study aimed to investigate the retinal and vitreal alterations in patients before and after contracting COVID-19 infection using swept-source optical coherence tomography (SS-OCT) and angiography (SS-OCTA). A total of 38 participants (76 eyes) were enrolled and followed-up 1 month after COVID-19 infection. Then, 26 patients (52 eyes) were evaluated 3 months after COVID-19 infection. Compared with the pre-COVID-19 status, patients with 1- and 3-month post-COVID-19 statuses had significant thinning of ganglion cell and inner plexiform layer, thickening of inner nuclear layer, a decrease in the vessel density (VD) of superficial vascular complex, and an increase in the VD of deep vascular complex. Meanwhile, alteration in parameters of foveal avascular zone (all p < 0.05) and hyper-reflective dots in the vitreous of 27 patients (54 eyes) (71.1% vs. pre-COVID-19, 34.2%, p = 0.006) were observed. These findings suggest significantly retinal and vitreal alterations occurred in patients after COVID-19 infection, possibly due to direct or indirect virus-induced injuries. Further longitudinal studies are required to investigate the long-term effects of COVID-19 infection on the human eyes.