Identification of the Risk Factors for Sight Threating Diabetic Retinopathy Presenting in a Tertiary Eye Hospital

Abstract

Diabetic retinopathy (DR) is a leading cause of blindness among working-age populations globally, with sight-threatening diabetic retinopathy (STDR) which includes diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR). So identifying the predominant risk factors is vital for targeted screening and prevention. This study aims to find the independent risk factors associated with the development of sight-threatening DR (STDR). A case-control study was conducted involving 50 type II diabetic patients. The case group (n=28) comprised patients diagnosed with DME or PDR, while the control group (n=22) consisted of diabetic patients with no diabetic retinopathy (NO DRP) or mild NPDR. Data on age, sex, diabetes duration (DM), hypertension (HTN), fasting blood sugar, postprandial blood sugar, and HbA1c were collected. Univariate and multiple logistic regression analyses were performed to calculate crude and adjusted odds ratios (ORs). In univariate analysis, DM duration (OR=1.19, 95% CI: 1.09-1.30, p<0.001), HbA1c (OR=3.87, 95% CI: 1.84-8.15, p<0.001), and postprandial blood sugar (OR=1.10 per 10 mg/dL, 95% CI: 1.01-1.20, p=0.035) were significant risk factors. However, in the multiple logistic regression model adjusting for all covariates, only DM duration remained a statistically significant independent predictor (Adjusted OR=1.20, 95% CI: 1.08-1.34, p=0.001). Patients with diabetes for over 10 years had a twelve-fold increased odds of STDR (OR=12.0, 95% CI: 2.70- 53.3) compared to those with less than 5 years' duration. Duration of diabetes is the strongest independent risk factor for sight-threatening diabetic retinopathy. While glycemic control is important, long-term exposure to the diabetic milieu appears to be the primary driver of disease progression. These findings underscore the critical need for intensified ophthalmologic surveillance in patients with long-standing diabetes.