# Increased Incidence of New-Onset Diabetic Retinopathy in Individuals with COVID-19 in an Underserved Urban Population in the Bronx

## TL;DR

People with type 2 diabetes who had COVID-19 were more likely to develop diabetic retinopathy within three years compared to those who did not have the virus.

## Contribution

This study identifies a significant association between SARS-CoV-2 infection and new-onset diabetic retinopathy in individuals with pre-existing type 2 diabetes.

## Key findings

- T2D patients with COVID-19 had a higher cumulative incidence of diabetic retinopathy compared to non-COVID-19 T2D patients.
- The adjusted hazard ratio for developing new DR was 1.70 in the COVID-19 group.
- Prior insulin use was strongly associated with increased DR risk in the study population.

## Abstract

Background/Objectives: To investigate the incidence of new-onset diabetic retinopathy (DR) in individuals with pre-existing type 2 diabetes (T2D) up to 3 years post SARS-CoV-2 infection. Methods: This retrospective study consisted of 5151 COVID-19 and 5151 propensity-matched non-COVID-19 patients with T2D in the Montefiore Health System between 1 March 2020 and 17 January 2023. The primary outcome was new-onset DR at least 2 months after the index date up to 17 January 2023. Matching for index date between groups was also used to ensure the same follow-up duration. Hazard ratios (HRs) were computed, adjusted for competing risks. Results: T2D patients with COVID-19 had a higher cumulative incidence of DR than T2D patients. The unadjusted HR for COVID-19 status for developing new DR was 2.44 [1.60, 3.73], p < 0.001. The adjusted HR was 1.70 [1.08, 2.70], p < 0.05, and the adjusted HR for prior insulin use was 3.28 [2.10, 5.12], p < 0.001. Sex, ethnicity, and major comorbidities had no significant association with outcome. Conclusions: T2D patients who contracted COVID-19 exhibited a significantly higher risk of developing DR within three years post infection compared to propensity-matched controls. The increased incidence was primarily driven by greater pre-existing insulin usage and SARS-CoV-2 infection in the COVID-19 positive cohort.