Quantification of retinal vein and artery trajectories using second-order polynomial equation in eyes with vitreomacular traction

Abstract

BackgroundsTo measure the degree of curvature of the retinal artery trajectory (RAT) and retinal vein trajectory (RVT) in the eyes of patients with vitreomacular traction (VMT) and compare them with their healthy fellow eyes. MethodsThis was a retrospective, cross-sectional, case-control study of 58 eyes of 29 patients with unilateral VMT. The participants were divided into two groups. Group 1 VMT was defined as having only morphological changes, while group 2 VMT was defined as morphological changes accompanied by the presence of a cyst or hole to quantify the severity of the disease. The RATs and RVTs were assessed from the color fundus photographs using the ImageJ program. The fundus photographs were rotated 90°. The course of the retinal arteries and veins were marked on a color fundus photograph and fitted to a second-degree polynomial curve (axe[x]/100+bx+c). The coefficient ‘‘a’’ was the width and steepness of the trajectories. The comparison between the RAT and RVT of VMT and healthy fellow eyes was investigated and the association between the RAT and RVT and the severity of disease were determined using the Image J program. ResultsEleven subjects were male, and 18 subjects were female. The mean ± SD age was 70.6 ± 7.6 years. Eighteen of the eyes had VMT in the right and 11 of the eyes had VMT in the left eye. Eleven eyes were in group 1 and 18 eyes were in group 2. Axial length (AL) was similar between the two groups (22.63 ± 1.20 mm vs 22.45 ± 1.45 mm p = 0.83) (Table 1). The mean RAT was 0.60 ± 0.18 in eyes with VMT and 0.51 ± 0.17in healthy eyes (p = 0.063). The mean RVT was 0.74 ± 0.24 in eyes with VMT and 0.62 ± 0.25 in healthy eyes for the whole group (p = 0.02). In group 1, the mean RVT of the eyes with VMT was statistically significantly higher than the healthy eyes (p = 0.014). There was not any statistically significant difference for the other parameters evaluated between eyes with VMT and healthy eyes according to the groups and the whole group. (Tables 2–4) ConclusionUnlike other vitreoretinal interface diseases such as epiretinal membrane and macular hole, VMT may be characterized by a narrower RVT, which is characterized by a larger “a” value.