Purpose: To analyze the efficacy and safety of ranibizumab in eyes with preproliferative (ischemic) central retinal vein occlusion.
Methods: In this prospective, phase I/II, open-label clinical trial, eyes at high risk of neovascular complications were identified; all eyes met ≥ 3 of 4 high-risk criteria: 1) the best-corrected visual acuity being ≤ 20/200, 2) loss of the 1-2e isopter on Goldmann visual field, 3) relative afferent pupillary defect being ≥ 0.9 log units, and 4) electroretinogram B-wave reduction to ≤ 60% of the corresponding A-wave. Monthly intravitreal ranibizumab treatment for 9 months, monthly monitoring for 3 months, and then monthly examination with pro re nata retreatment on evidence of disease activity for 24 months were performed. Therefore, the total study duration was 36 months.
Results: The main outcome measures were mean change in the best-corrected visual acuity and central macular thickness by optical coherence tomography, proportion of patients with neovascular complications, and the incidence and severity of ocular and nonocular adverse events. Twenty patients were enrolled in the Rubeosis Anti-VEgf trial, and the mean number of intravitreal treatments administered through Months 24 and 36 were 14.1 and 17.2, respectively. The mean best-corrected visual acuity letters gained were +21.1 and +21.4 at 9 and 36 months, respectively. The mean central macular thickness improved -294 μm from baseline after 9 monthly treatments. Subsequently, after 3 months of observation, the mean central macular thickness increased +203 μm. On initiation of pro re nata ranibizumab retreatment, the mean central macular thickness then improved -191 μm at Month 36 compared with Month 12. Nine patients developed neovascular complications, being diagnosed after a mean of 24-month follow-up (range, 3-44 months), with 2 patients developing neovascularization after completion of the 36-month trial endpoint (at Months 42 and 44 after study enrollment).
Conclusion: Intravitreal ranibizumab therapy can improve retinal anatomy and vision in eyes with severe central retinal vein occlusion. Despite significant clinical benefit with antivascular endothelial growth factor therapy, the risk of neovascular complications was not ameliorated by vascular endothelial growth factor blockade, but was merely delayed.