Morphometric Analysis of Retinal Vessels Using High-Resolution OCT Technology in Healthy Subjects.

Purpose: To assess the performance of a novel high-resolution optical coherence tomography (High-Res OCT) research platform with 3-µm axial resolution in measuring retinal vascular metrics in healthy subjects, and to compare it with standard OCT. Methods: This observational, cross-sectional study comprised two phases. In Phase I, 36 eyes underwent imaging with both standard and High-Res OCT to assess inter-device and inter-grader agreement. In Phase II, an expanded cohort was imaged exclusively with High-Res OCT to investigate the possible associations between vascular wall metrics and systemic factors. Vascular measurements included anterior and posterior wall thickness and vessel diameter, manually assessed using standardized OCT protocols. Linear mixed-effects models were used to evaluate associations with clinical variables. Results: Eighty-seven eyes from 44 healthy subjects were overall included. Inter-grader agreement was excellent for High-Res OCT (intraclass correlation coefficient [ICC] range 0.94-0.96) and good to excellence for standard OCT (ICC range 0.83-0.88). Both the arterial and venous wall thickness were significantly thinner when measured by High-Res OCT compared to standard OCT (P < 0.001). The entire vessel diameter was similar across the two techniques in both arteries and veins (P > 0.05). Arterial walls thickness was significantly greater in males (P = 0.033) and positively associated with age (P < 0.001). Similar age-related trends were observed in venous wall thickness (P = 0.006). Conclusions: High-Res OCT improved visualization and reproducibility of retinal vascular wall metrics compared to standard OCT. These findings suggest its future potential role in noninvasive vascular imaging and systemic health assessment.