MORPHOLOGICAL CHANGES OF THE MACULA ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN THE DIABETIC POPULATION

Abstract

Objective: This study aims to investigate morphological alterations in the macula using Optical Coherence Tomography Angiography (OCTA) among diabetic patients, focusing on quantitative changes in the foveal avascular zone (FAZ) and qualitative retinal microvascular features, with the ultimate goal of understanding early diagnostic markers for diabetic retinopathy (DR).

Methods: A descriptive, observational, cross-sectional study was conducted at the Ophthalmology Department of Dr. Ruth K. M. Pfau Civil Hospital, Karachi. A total of 315 diabetic patients, aged 18 years and above, were evaluated using OCTA. The scan parameters were standardized, and the FAZ area, intraretinal microvascular abnormalities (IRMA), microaneurysms, capillary non-perfusion, and neovascularization were documented and analyzed against the duration of diabetes and stage of diabetic retinopathy (NPDR, PDR, ADED).

Results: NPDR was the most prevalent stage of DR (72.7%). The mean FAZ area was significantly larger in patients with PDR and ADED stages, with mean values reaching up to 2.79 mm² in the most advanced disease. Significant differences were found in FAZ size between different DR stages. Over 80% of patients with DR showed microaneurysms, while non-perfusion areas and IRMA were more prevalent in advanced stages. The duration of diabetes was strongly associated with the extent of FAZ enlargement and severity of retinal changes.

Conclusion: OCTA provides a high-resolution, non-invasive, and reproducible method for detecting microvascular changes in diabetic patients before clinical symptoms manifest. FAZ area and retinal microvascular abnormalities can be used as sensitive biomarkers for DR staging and prognosis. Integrating OCTA into routine diabetic screening can significantly reduce vision loss through early detection and timely intervention.