This study aims to evaluate the role of Optical Coherence Tomography Angiography in the early detection of diabetic retinopathy by identifying and standardizing retinal microvascular biomarkers. Diabetic retinopathy is a major cause of preventable vision loss, and early diagnosis before the appearance of clinical signs is critical for timely intervention.

The study will be a prospective cross sectional observational study involving type 2 diabetic patients with no or mild to moderate non proliferative diabetic retinopathy and age matched non diabetic controls. OCTA will be used to assess key biomarkers such as vessel density, foveal avascular zone area, perfusion density, and other microvascular and structural retinal parameters. These findings will be correlated with systemic diabetic control markers including HbA1c and functional visual outcomes such as best corrected visual acuity and contrast sensitivity.

The diagnostic performance of OCTA will be compared with conventional imaging techniques like fundus photography and fluorescein angiography. Statistical analysis will be used to establish standardized threshold values for OCTA biomarkers that can reliably differentiate early diabetic retinopathy from normal retinal findings.

The expected outcome is to validate OCTA as a sensitive and non invasive tool for early detection and monitoring of diabetic retinopathy, enabling earlier diagnosis, better risk stratification, and improved personalized management for patients at risk of diabetic vision loss.