OCT-Based Retinal Vasculature Analysis: Age, Sex, and Body Mass Index Associations in the Nagahama Study, a Large Japanese Cohort

Objective: This study aimed to evaluate retinal vessel structure using OCT, which enables high-resolution imaging for detailed vascular assessment. We investigated how age, sex, and body mass index (BMI) influence the OCT-measured parameters, including outer and inner diameters (ODs and IDs, respectively), wall thickness, and wall reflectivity-parameters that are challenging to assess using color fundus photography.

Design: A cross-sectional retrospective study.

Participants: The study included 6981 participants in the Nagahama Study, with 6981 eyes being assessed.

Methods: OCT B-scan images centered on the optic disc were obtained. For each participant, mean values of the ODs and IDs, wall thickness, and wall reflectivity of the 4 largest arteries and veins were measured.

Main outcome measures: Associations of retinal vessel parameters with age, sex, and BMI were evaluated. The reliability of OCT-measured parameters was assessed using intraclass correlation coefficients. Multivariable linear regression adjusted for intraocular pressure and axial length was used to investigate the associations with demographic and anthropometric factors.

Results: Intraclass correlation coefficients for retinal vessel parameters demonstrated good-to-excellent reliability (0.767-0.957, P < 0.001). Compared with those of veins, arterial diameters were smaller, and arterial wall thickness and reflectivity were greater. Multivariable analysis revealed a U-shaped association between age and arterial diameter. Participants aged ≥60 years had significantly larger diameters than those aged 30 to 40 years and those in their 50s. Venous diameter decreased linearly with age. The arterial wall thickness and reflectivity increased with age. Women exhibited larger arterial diameters than men. Body mass index was negatively associated with the arterial diameter and positively associated with the venous diameter and arterial wall thickness.

Conclusions: OCT enabled detailed evaluation of retinal vessel structure, allowing for the measurement of parameters that are challenging to assess by fundus photography, such as IDs and ODs, wall thickness, and wall reflectivity. This study, conducted in a large Japanese cohort, demonstrated significant associations between these OCT-measured retinal vascular parameters and age, sex, and BMI. These findings support the potential of OCT as a valuable tool for objective, in-depth assessment of retinal vascular health and its relationships with demographic and anthropometric factors.

Financial disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.