Macular Vascular Geometry Changes With Sex and Age in Healthy Subjects: A Fundus Photography Study

Purpose: To characterize the sex- and age-related alterations of the macular vascular geometry in a population of healthy eyes using fundus photography.Methods: A cross-sectional study was conducted with 610 eyes from 305 healthy subjects (136 men, 169 women) who underwent fundus photography examination and was divided into four age groups (G1 with age <= 25 years, G2 with age 26-35 years, G3 with age 36-45 years, and G4 with age >= 46 years). A self-developed automated retinal vasculature analysis system allowed segmentation and separate multiparametric quantification of the macular vascular network according to the Early Treatment Diabetic Retinopathy Study (ETDRS). Vessel fractal dimension (D-f), vessel area rate (VAR), average vessel diameter (D-m), and vessel tortuosity (tau(n)) were acquired and compared between sex and age groups.Results: There was no significant difference between the mean age of male and female subjects (32.706 +/- 10.372 and 33.494 +/- 10.620, respectively, p > 0.05) and the mean age of both sexes in each age group (p > 0.05). The D-f, VAR, and D-m of the inner ring, the D-f of the outer ring, and the D-f and VAR of the whole macula were significantly greater in men than women (p < 0.001, p < 0.001, p < 0.05, respectively). There was no significant change of tau(n) between males and females (p > 0.05). The D-f, VAR, and D-m of the whole macula, the inner and outer rings associated negatively with age (p < 0.001), whereas the tau(n) showed no significant association with age (p > 0.05). Comparison between age groups observed that D-f started to decrease from G2 compared with G1 in the inner ring (p < 0.05) and D-f, VAR, and D-m all decreased from G3 compared with the younger groups in the whole macula, inner and outer rings (p < 0.05).Conclusion: In the healthy subjects, macular vascular geometric parameters obtained from fundus photography showed that D-f, VAR, and D-m are related to sex and age while tau(n) is not. The baseline values of the macular vascular geometry were also acquired for both sexes and all age groups.