Effect of sex in branch retinal vein occlusion

Purpose. To evaluate the effect of sex in relation to crossing numbers, art erial overcrossings and occlusion sites in patients with branch retinal vei n occlusion (BRVO). Methods. Fifty-one eyes with BRVO (study group) and 48 eyes with retinal pr oblems other than BRVO (control group) were investigated All venous occlusi ons were examined in detail with regard to their anatomical positions, site s and arteriovenous crossings on the retinal surrounding area two disc diam eters nasally, four disc diameters temporally three disc diameters superior ly and three inferiorly from the optic disc, in the arteriovenous phase of fundus fluorescein angiography and fundus color photography. Results. The study group comprised 29 women (56.86%) and 22 men (43.14%). A ll occlusions were unilateral and located at the crossing areas. BRVO had a rterial overcrossing in 28 eyes (96.6%) in females and 22 eyes (95.5%) in m ales (p > 0.005). The average numbers of crossings were 7.79 +/- 1.57 in fe males and 7.82 +/- 1.05 in males in the study group (p > 0.05), and respect ively 7.30 +/- 1.19 and 6.95 +/- 1.13 (p > 0.05) in the control group. The average arterial overcrossing ratios were 75% in females and 71% in males i n the study group (p > 0.05), and 74% and 65% in the control group (p > 0.0 5). Conclusions. Our data suggest that females ha ve a higher risk than males b ecause of their arterial overcrossing ratio and BRVO prefer arterial overcr ossing. However the insignificant difference between the female and male pa tients leads us to assume that the effect of sex on BRVO cannot be explaine d only by local anatomical factors since their effect is only slight.