Branch retinal vein occlusion. Axial length and other risk factors.

OBJECTIVE: To determine the association between axial length, as a measurement of hyperopia, and branch retinal vein occlusion and to determine the clinical characteristics and other risk factors of patients with branch retinal vein occlusion.

METHODS: A case-control study was performed using 36 patients with branch retinal vein occlusion and 36 age- and sex-matched control patients selected from a list of subjects who had undergone cataract extraction.

RESULTS: There was essentially no difference in axial length between patients the disorder and control patients (23.55 mm versus 23.62 mm; P = 0.79). Although the intraocular pressure (IOP) among control eyes was somewhat higher than that in branch retinal vein occlusion eyes, the difference was not statistically significant (P = 0.32). Systemic hypertension was more common in patients with branch retinal vein occlusion (53%) than in control patients (42%) but the difference was not statistically significant (P = 0.35). Chronic open-angle glaucoma was present in 14% of patients with branch retinal vein occlusion and 22% of control patients (P = 0.37), but this difference was not statistically significant. Diabetes mellitus was two times more common in controls (28%) than in patients with branch retinal vein occlusion (14%). This difference, however, also did not reach statistical significance (P = 0.13).

CONCLUSIONS: Hyperopia as measured by axial length is not a risk factor for branch retinal vein occlusion. This study provides evidence that hypertension is a risk factor for branch retinal vein occlusion and that chronic open-angle glaucoma and diabetes mellitus are not risk factors for branch retinal vein occlusion.