Relationship between retinal artery trajectory and axial length in Japanese school students

The trajectories of the supratemporal and infratemporal retinal arteries are associated with the position of the nerve fiber layer defects of glaucomatous eyes. However, no reports have thus far been published on changes in the retinal artery trajectory (RA trajectory) along with growth. Thus, the purpose of this study was to investigate the differences in the RA trajectories of elementary and junior high school students and the associations with axial length (AL). Prospective cross-sectional observational study. In total, 122 right eyes of healthy elementary school students (61 boys, 61 girls) and 170 right eyes of healthy junior high school students (83 boys, 87 girls) were studied. The AL was measured and color fundus photographs were taken, and used for the analysis. The RA trajectory was plotted in the color fundus photographs and fitted to a second-degree polynomial equation, , using ImageJ. The coefficient "a" represented the steepness of the trajectories. The differences in the RA trajectories and ALs of elementary and junior high school students were determined using the Mann-Whitney test. The association between the RA trajectory and AL was determined using the Spearman rank correlation. The AL and the RA trajectory of the junior high school students were significantly greater than those of the elementary school students (P < 0.001). The RA trajectory was significantly associated with the AL in both elementary (r = 0.26, P = 0.005) and junior high (r = 0.32, P < 0.001) school students. Junior high school students have a longer AL and narrower RA trajectory than do elementary school students. A longer AL is associated with a narrower RA trajectory in both elementary and junior high school students.