Axial length as a risk factor to branch retinal vein occlusion.

Abstract

To determine whether axial length is a factor in branch retinal vein occlusion. Axial length measurements in a group of 24 patients with a unilateral branch retinal vein occlusion were compared with the axial length measurements in a control group. Axial length measurements were taken with an A-scan; affected and unaffected eyes were measured. The control group consisted of 24 individuals who matched the patients in the branch retinal vein occlusion group in age, systemic hypertension status, and diabetes mellitus status. The affected and fellow eye in patients in the branch retinal vein occlusion group did not differ statistically in axial length (P = 0.26). The mean axial length of affected eyes in the branch retinal vein occlusion group was 22.76 +/- 0.92 mm, and the mean axial length of control eyes was 23.36 +/- 1.08 mm. The difference in axial length between the eyes with a branch retinal vein occlusion and the eyes in the control group was statistically significant (P = 0.023). The axial length of affected eyes of patients with branch retinal vein occlusion was on average 0.60 mm shorter than that of eyes of matched controls (95% confidence interval, 0.30-0.90 mm). The shorter axial length could be a local risk factor in the pathogenesis of a branch retinal vein occlusion.