Vitreous changes in retinal branch vein occlusion.

The vitreous was studied in 50 eyes with retinal branch vein occlusion (RBVO) and compared to an age-matched control group. The incidence of partial vitreous detachment was significantly higher (22%) in the RBVO group than in the control group (2.2%) (P less than 0.01). The incidence of preretinal neovascularization in the RBVO group was 22%. No new vessels formed in eyes with complete posterior vitreous detachment (P less than 0.05). The risk of vitreous hemorrhage was greatest in patients with partial vitreous detachment (64%). There was no significant correlation between the status of the vitreoretinal relationship and the development of macular edema, which occurred in 56% of the patients. In two patients, intermittent vitreous traction on the fovea may have influenced the evolution of chronic macular edema and lamellar hole formation. Vascular occlusive disease of the retina produces significant changes in the overlying vitreous. These vitreous changes in turn influence the development of complications following retinal vascular occlusions.