ROLE OF THE VITREOUS IN CENTRAL RETINAL VEIN OCCLUSION

Purpose: The role of the vitreous in eyes with CRVO and its relationsh ip to neovascularization and macular edema, in particular, were invest igated. Methods: A retrospective chart review of the vitreous conditio n of 136 patients (136 eyes) with CRVO was performed. Based on fluores cein angiography findings and color photographs, eyes with CRVO were c lassified as either ischemic or nonischemic. Results: In ischemic case s, retinal or optic disc neovascularization or both developed in 8 (57 %) of 14 eyes with no or partial posterior vitreous detachment (PVD) a t the final examination. The prevalence of neovascularization was sign ificantly higher than in eyes with complete PVD (0%, 0 of 38) at the f inal examination (P < 0.01). No significant relationship was found bet ween iris neovascularization development and the vitreous condition or between the prevalence of PVD and macular edema. In nonischemic eyes, the prevalence of no PVD or partial PVD with vitreomacular attachment was significantly higher in those with macular edema (76%, 25 of 33) than in eyes without (25%, 13 of 51) at the final examination (P < 0.0 1). Conclusion: Complete PVD may protect against retinal or optic disc neovascularization in eyes with severe CRVO. Vitreomacular attachment may cause persistent macular edema in eyes with mild CRVO.