[Screening of microvascular and neurodegenerative complications of diabetes mellitus using ophthalmic examination...

Introduction: Diabetes mellitus is associated with severe microvascular and neurodegenerative complications, making early detection crucial for prevention and treatment. Optical coherence tomography angiography (OCTA) and in vivo confocal microscopy (IVCM) are non-invasive imaging techniques that enable the early detection of retinal microvascular changes and corneal nerve fiber morphological alterations. Method: In this cross-sectional study, we enrolled 30 diabetic patients and 30 age-matched healthy controls. OCTA was used to analyze vascular density in the superficial and deep capillary plexuses and to measure the foveal avascular zone. IVCM was utilized to quantify the morphological parameters of corneal subbasal nerve fibers. Results: Diabetic patients showed a significant reduction in vascular density in the superficial capillary plexus, particularly in the nasal, superior, and temporal quadrants (p<0.05). These changes showed an inverse correlation with the disease duration. IVCM revealed a marked decrease in corneal nerve fiber density and length (p<0.05), which appeared to be independent of disease duration and HbA1c levels. Conclusion: Our findings suggest that morphological damage to corneal nerve fibers occurs earlier than retinal microvascular alterations in diabetes. Both IVCM and OCTA may serve as potential biomarkers for the early detection of complications in patients with type 1 and type 2 diabetes, offering opportunities for screening and monitoring disease progression. Orv Hetil. 2025; 166(24): 953–960.