Influence of Refractive Condition on Retinal Vasculature Complexity in Younger Subjects

Objective. The aim of this study was to compare the retinal vasculature complexity between emmetropia, and myopia in younger subjects. Methods. A total of 82 patients (24.12 ± 1.25 years) with two types of refractive conditions, myopia and emmetropia were enrolled in this study. Refraction data were converted to spherical equivalent refraction. These retinal images (right eyes) were obtained from NAVIS Lite Image Filing System and the vasculature complexity was measured by fractal dimension (D (f)), quantified using a computer software following a standardized protocol. Results. There was a significant difference (P < 0.05) in the value of D (f) between emmetropic (1.5666 ± 0.0160) and myopic (1.5588 ± 0.0142) groups. A positive correlation (rho = 0.260, P < 0.05) between the D (f) and the spherical equivalent refraction was detected in this study. Using a linear model, it was estimated that 6.7% of the variation in D (f) could be explained by spherical equivalent refraction. Conclusions. This study provides valuable findings about the effect of moderate to high myopia on the fractal dimension of the retinal vasculature network. These results show that myopic refraction in younger subjects was associated with a decrease in D (f), suggesting a loss of retinal vessel density with moderate to high myopia.