Retinal Findings on OCT in a COVID-19 Patient Cohort

The current worldwide COVID-19 pandemic caused by SARS-CoV2 has generated an urgency to understand the implications of this disease in the eye. Possible retinal involvement by SARS-CoV2 infection has been a topic of heated debate. Objective: To determine whether retinal abnormalities can be identified on Optical Computed Tomography (OCT) in convalescent patients following COVID-19 infection. Methodology: This is a prospective, case controlled study that recruited COVID-19 patients who were admitted to the United Christian Hospital Hong Kong, China. At 2 months post-recovery, patients’ visual acuity, refraction were measured. Spectraldomain OCT of the macula to retinal nerve fiber layer and enhanced depth imaging were performed. Age-matched and refraction-matched healthy individuals that were not infected with COVID-19 were enrolled as controls. Qualitative and quantitative assessments of retinal abnormalities on OCT and retinal and choroidal layer thickness were done. Results: 20 subjects (40 eyes) with COVID-19 and 25 (50 eyes) healthy controls were enrolled. Structural OCT abnormalities were observed in 24% of control eyes and in 25% of COVID-19 subjects. No differences were observed between the post- COVID-19 cohort and the healthy controls for any qualitative retinal abnormalities or in any quantitative features including retinal volume, choroidal thickness, retinal layer thicknesses in various macular regions, and peripapillary nerve fiber layer thickness. Conclusion: Following full recovery from symptomatic COVID-19 infection, no significant abnormalities were evident on structural OCT as compared to controls. Although long-term damage to the retina appears to be uncommon after COVID-19 infection, this study provides valuable insight into the recovery process after COVID-19 and provides potential differentiating retinal features that should be considered in future studies involving a larger population.