Purpose: To investigate the effect of cup to disk (C/D) ratio in various types of retinal vein occlusion (RVO) on the severity of retinopathy, visual outcome, and resolution of retinopathy and validity of the concept of the "compartment syndrome" in RVO.
Methods: The study comprised 1,222 consecutive eyes (768 central retinal vein occlusion [CRVO], 183 hemi-CRVO, and 271 branch retinal vein occlusion). Ophthalmic evaluation at initial and follow-up visits included recording visual acuity, visual fields, and detailed anterior segment and fundus examinations and fluorescein fundus angiography.
Results: Compared to sex-matched and age-matched normal eyes, C/D ratio ≥0.5 was significantly more common in all CRVOs and hemi-CRVO eyes but not in branch retinal vein occlusion. Retinal hemorrhages were significantly more severe in nonischemic CRVO with C/D ratio ≥0.5 compared to those with no or small cup, but no difference was found in hemi-CRVO and branch RVO. In ischemic CRVO, moderate hemorrhages were more with C/D ≥0.5 but severe hemorrhages were more with no cup. In various types of RVO, there was no significant association of C/D ratio with macular edema, retinopathy resolution, visual acuity, and visual field defect.
Conclusion: The findings of our study contradict the concept that the "compartment syndrome" plays any role in the prevalence of various types of RVO or in their severity, the resolution of retinopathy, or the visual outcome. This indicates that the advocated procedure of radial optic neurotomy, based on the compartment syndrome, is not a logical treatment for CRVO.