Frequency of Macular Edema in Diabetic Retinopathy

Abstract

Diabetic macular edema is a major vision-threatening complication of diabetic retinopathy and may lead to significant loss of central vision. Optical coherence tomography allows objective detection of macular edema and helps identify patients who require early intervention. Objective: To determine the frequency of macular edema among patients with diabetic retinopathy and to assess its association with demographic, clinical, and ophthalmic factors. Methods: This hospital-based cross-sectional study was conducted in the Ophthalmology Unit of Ayub Teaching Hospital, Abbottabad, Pakistan, from 12 June 2025 to 12 September 2025. A total of 196 patients aged 40–80 years with type 2 diabetes mellitus and diagnosed diabetic retinopathy were enrolled using non-probability consecutive sampling. Demographic data, body mass index, duration of diabetes, HbA1c, visual acuity, diabetic retinopathy stage, and optical coherence tomography findings were recorded. Macular edema was diagnosed using OCT findings, including increased central macular thickness and macular retinal thickening. Data were analyzed using SPSS version 20. Associations were assessed using chi-square test or Fisher’s exact test, with p≤0.05 considered statistically significant. Results: The mean age of patients was 56.8 ± 9.4 years. There were 106 male patients (54.1%) and 90 female patients (45.9%). The mean duration of diabetes was 9.2 ± 4.8 years, mean HbA1c was 8.4 ± 1.3%, and mean central macular thickness was 336.4 ± 91.2 microns. Macular edema was detected in 100 patients, giving an overall frequency of 51.0%. The frequency increased with advancing diabetic retinopathy stage, from 22.0% in mild non-proliferative diabetic retinopathy to 81.3% in proliferative diabetic retinopathy. Patients with macular edema had significantly higher age, BMI, duration of diabetes, HbA1c, random blood sugar, central macular thickness, and poorer visual acuity compared with those without macular edema. Macular edema was significantly associated with increasing age, higher BMI, longer duration of diabetes, poor glycemic control, and advanced diabetic retinopathy stage, while gender and residence showed no significant association. Conclusion: Macular edema was present in approximately half of the patients with diabetic retinopathy in this tertiary-care Pakistani cohort. Older age, overweight or obesity, longer diabetes duration, poor glycemic control, and advanced diabetic retinopathy were significantly associated with macular edema. Routine OCT-based macular assessment should be prioritized in high-risk diabetic retinopathy patients to support early diagnosis and timely management.