Abstract
Purpose: :
To characterize the onset of and identify factors associated with neovascularization in eyes with CRVO undergoing anti-vascular endothelial growth factor (VEGF) therapy. The onset of neovascular events such as neovascularization of the iris (NVI) or neovascular glaucoma (NVG) in the context of serial anti-VEGF injections has not been well characterized.
Methods: :
Consecutive patients at Wills Eye Institute who underwent intravitreal bevacizumab (IVB) or ranibizumab (IVR) for treatment of CME secondary to CRVO between 2005 and 2011 were retrospectively reviewed. Eyes treated at least twice with IVB or IVR were included. Data collected included age, perfusion status of CRVO, onset of CRVO, best corrected visual acuity (BCVA), and type and onset of neovascular event.
Results: :
Twenty eyes of twenty patients were identified. Mean duration of CRVO prior to treatment was 3.2 months (standard deviation or SD = 4.2 months). Mean follow-up was 26.7 months (SD = 14.7 months). At baseline 14 eyes (70%) demonstrated 10 or greater disk diameters of nonperfusion based on fluorescein angiography and were categorized as ischemic. Patients received between 2 and 12 IVB or IVR injections (mean=4.9) prior to any neovascular event. Mean time from first visit to any neovascular event was 13.3 months (SD = 9.0 months). Mean treatment free interval from last IVB or IVR to any neovascular event was 5.3 months (SD = 5.6 months). Neovascularization of the iris or angle was observed in 12 eyes (60%), vitreous hemorrhage was observed in 7 eyes (35%), and neovascularization of the disk was observed in 1 eye (5%). All neovascular events necessitated panretinal photocoagulation and 4 eyes (20%) required glaucoma shunt surgery. Of the 20 eyes, 14 (70 %) presented with vision 20/400 or worse and 15 (75%) demonstrated 20/400 or worse vision after two anti-VEGF injections.
Conclusions: :
Neovascular events may occur both in patients undergoing concurrent monthly anti-VEGF therapy as well as patients who have discontinued therapy. These events are delayed compared to the natural history of CRVO related neovascular events.
Keywords: neovascularization • age-related macular degeneration • drug toxicity/drug effects