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 (τ(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 τ(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 τ(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 τ(n) is not. The baseline values of the macular vascular geometry were also acquired for both sexes and all age groups.