Effects of COVID-19 on Retinal and Choroidal Thickness by Optical Coherence Tomography

Precis:The aim of our study was to evaluate the subclinical changes in the macula, retinal nerve fiber layer (RNFL), and choroidal thickness after coronavirus disease 2019 (COVID-19) infection using spectral domain optical coherence tomography. Methods:Our study was prospectively designed and involved 170 eyes of 85 patients. Patients with polymerase chain reaction (PCR)-positive COVID-19 infection were examined in the ophthalmology clinic before and after infection were included. All included patients had mild COVID-19 with no hospitalization and no need for intubation. Control ophthalmic examination was repeated at least 6 months after PCR positivity. Macular and choroidal thickness and RNFL parameters were compared before and at least 6 months after PCR-positive COVID-19 infection using optical coherence tomography. Results:When the mean macular thickness data were evaluated, a significant decrease was detected in the inner (mean difference, -3.37 & mu;m; 95% CI: -6.09 to -0.65, P = 0.021) and outer (mean difference, -6.56 & mu;m; 95% CI: -9.26 to -3.86, P < 0.001) temporal segments and the inner (mean difference, -3.39 & mu;m; 95% CI: -5.46 to -1.32, P = 0.002) and outer (mean difference, -2.01 & mu;m; 95% CI, -3.70 to -0.31, P = 0.018) superior segments in the post-COVID-19 measurements compared with pre-COVID-19 measurements. Similarly, on RNFL evaluation, some thinning was evident in the temporal superior (mean = 1.14 & mu;m, P = 0.004) and temporal inferior (mean = 1.30 & mu;m, P = 0.032) regions. All choroidal regions, including central, nasal 500 & mu;m and 1500 & mu;m and temporal 500 & mu;m and 1500 & mu;m, exhibited significant thinning (P < 0.001). Conclusion:At least 6 months after mild COVID-19 infection, significant thinning was seen in the temporal and superior quadrants of the macula, the temporal superior and temporal inferior regions of the RNFL, and all measured areas of choroidal regions.