Ocular surface impairment after COVID-19: a cohort study.

PURPOSE Cohort study to evaluate the presence of objective signs and subjective symptoms of dry eye disease (DED) in post-COVID-19 patients compared to control. METHODS Prospective, observational, single-center, cohort study. Sixty-four post-COVID-19 patients and fifty control were recruited. All participants underwent a complete ophthalmological examination including: Ocular Surface Disease Index Questionnaire (OSDI), Best Corrected Visual Acuity (BCVA), slit lamp biomicroscopy, fundus examination, Schirmer test type 1, Tear Break Up Time test (tBUT), evaluation of conjunctival hyperemia, corneal staining and tear film osmolarity test. RESULTS OSDI score was higher in the post-COVID19 group in the quantitative and qualitative analysis (respectively p<0.001 and p =0.012). Mean tBUT in post-COVID-19 patients was 6.95 ± 4.07 sec compared to a mean tBUT of 10.12 ± 3.90 sec in the control group. The post-COVID-19 group showed a higher number of patients with a simultaneous impairment of OSDI score and tBUT (p = 0.019). The Schirmer test results were strikingly significant both in the quantitative and qualitative analysis (p <0.001 and p = 0.0014 respectively). Both quantitative and qualitative analysis revealed a significant difference in terms of tear osmolarity in the two groups. CONCLUSIONS Comparing the ocular surface assessment of post-COVID-19 patients with heathy control a statistically significant increase of DED has emerged both in subjective and objective evaluations. Our clinical results support the findings that suggested a susceptibility of the ocular surface to the virus and it underlines the importance of the ocular surface assessment in post-COVID-19 patients for a correct diagnosis and therapy.