The impact of diabetes duration on retinal thickness

Background: Diabetes mellitus (DM) microvascular complications consist of diabetic retinopathy (DR) and diabetic macular edema (DME) which result in permanent vision loss. Early detection of retinal structural changes including central retinal thickness (CRT) and macular thickness and retinal nerve fiber layer (RNFL) thickness can be achieved through optical coherence tomography (OCT). The understanding of diabetes duration in relation to retinal thickness parameters enables early detection and treatment of the condition. Objective: To assess the impact of duration of diabetes mellitus on retinal thickness parameters on SD-OCT and to investigate the relationship between the duration of the disease and the occurrence of DME in adult diabetic patients.+ Methods: This observational cross-sectional study involved 350 diabetic patients of both type 1 and type 2 from Tikrit Teaching Hospital and a private ophthalmology clinic in Iraq, during February 2024 and February 2025. Patients were stratified into three groups based on duration of diabetes: Group A (