Central Macular Thickness and Foveal Avascular Zone are Indicators of Early Diabetic Retinopathy.

Abstract

Purpose: Diabetic retinopathy (DR) is one of the most common complications in diabetic patients, and early diagnosis and intervention are crucial for slowing disease progression. This study aims to investigate the changes in central macular thickness (CMT) and foveal avascular zone (FAZ) area in healthy individuals, patients with no apparent diabetic retinopathy (NDR), and patients with non-proliferative diabetic retinopathy (NPDR), and to explore the potential risk factors for early DR.

Methods: This cross-sectional study included 60 healthy individuals, 60 patients with no DR, and 60 patients with mild NPDR. All participants underwent comprehensive ophthalmic examinations. Central macular thickness (CMT) was measured using optical coherence tomography (OCT), and the FAZ area was measured using optical coherence tomography angiography (OCTA). The potential associations between CMT and FAZ area and systemic risk factors for early DR (including duration of diabetes, body mass index (BMI), glycated hemoglobin (HbA1c), lipid profile, and blood pressure) were analyzed.

Results: Significant differences in CMT and FAZ area were observed in both the right and left eyes of the NPDR and NDR groups compared to the control group (p<0.05). The CMT and FAZ area also showed significant differences between the NPDR and NDR groups (p<0.05). Additionally, CMT was positively correlated with the duration of diabetes, BMI, total cholesterol (TC), triglyceride (TG), systolic blood pressure, and diastolic blood pressure (p<0.05). FAZ area was positively correlated with the duration of diabetes and BMI (p<0.05).

Conclusion: The increase in CMT and the reduction in macular perfusion may be the earliest retinal structural changes in diabetic patients, and both changes are closely related to systemic factors. These findings provide important structural and metabolic indicators for the early identification and intervention of diabetic retinopathy.