Progression of Diabetic Retinopathy during COVID-19 Pandemic: A Retrospective Study

Introduction: Emergence and subsequent exponential spread of Coronavirus Disease-2019 (COVID-19) infection during 2020 forced the Government to issue countrywide lockdown from March 2020. Diabetic Retinopathy (DR) is one of the debilitating diseases of the eye which requires regular follow-ups and timely intervention to prevent permanent vision loss. The impact of countrywide lockdown on prevalence and progression of DR needs to be evaluated.

Aim: To assess the effect of COVID-19 pandemic situation on the prevalence and progression of DR and analyse the possible risk factors for progression of DR in the ongoing pandemic period by comparing retrospective data from immediate prepandemic quarter with post lockdown quarter.

Materials and Methods: This retrospective study was conducted in the Department of Opthalmology at Regional Institute of Ophthalmology, Kolkata, West Bengal, India. The study was done during the prepandemic period, from November 2019 to February 2020. In the present study, a cohort of 83 diabetic patients with pre-existing DR was selected from past medical records and compared with post lockdown period during November 2020 to February 2021. Data regarding prevalence of various types of DR, mean Central Macular Thickness (CMT), mean Visual Acuity (VA), proportion of patients requiring >3 doses of monthly anti-Vascular Endothelial Growth Factors (VEGF) and additional laser therapy or vitrectomy, VA improvement and reduction of mean CMT were gathered and compared between those two quarters. The data was analysed using Statistical Package for Social Sciences (SPSS) version 25.0.

Results: The prevalence of moderate Non Proliferative Diabetic Retinopathy (NPDR) (13% vs 25%), severe NPDR (19% vs 8%), Proliferative DR (PDR) (18% vs 7%), Advanced Diabetic Eye Disease (ADED) (4.8% vs 1%) and Diabetic Macular Oedema (DME) (62% vs 28%) increased several folds during post lockdown quarter in comparison to prepandemic quarter. There was a statistically significant difference (p-value<0.05) in baseline mean LogMar Best Corrected Visual Acuity (BCVA) (0.4±0.08 vs 0.9±0.07), mean CMT (386.4±26.8 to 421.8±21.6) positive correlations of some of the possible risk factors for poor visual outcome among the same cohort of patients in the post lockdown period: poor socioeconomic status (35%; Odds Ratio (OR):3.59, Relative Risk (RR):2.68), irregular diabetic medication (52%; OR:3.56, RR:2.23), residence more than 100 km from the hospital (38%; OR:3.03, RR:2.26).

Conclusion: The present study, concludes that, the status of DR stage among study subjects in the post lockdown period has deteriorated when compared with the prepandemic period.