Intravitreal bevacizumab in acute central/hemicentral retinal vein occlusions: three-year results of a prospective clinical study.
PURPOSE
To prospectively evaluate the effects of intravitreal bevacizumab (IVB, Avastin; Genentech, Inc., San Francisco, CA) injections in patients with acute central/hemicentral retinal vein occlusions (C/HCRVOs) (≤1 month after the occlusion was diagnosed) over the course of 3 years.


METHODS
The study included 57 patients with unilateral acute C/HCRVOs. Initially, the treatment for acute C/HCRVO patients consisted of 4 consecutive IVB injections administered off-label at a dose of 2.5 mg per injection, with each injection spaced ∼45 days apart. Thereafter, IVB therapy was flexible, and subsequent injections were administered during scheduled visits whenever a best corrected visual acuity (BCVA) loss of ≥5 Early Treatment Diabetic Retinopathy Study (ETDRS) letters occurred and/or iris/angle neovascularization appeared (regardless of the intraocular pressure level). Changes in the BCVA and foveal thickness (FT), number of IVB injections administered, and incidence of neovascular glaucoma (NVG) were estimated.


RESULTS
The increase in the BCVA score at month 36 was 17.15 (ETDRS letters) (P<0.0001) in cases of nonischemic and 26.81 (ETDRS letters) (P<0.01) in cases of ischemic occlusions. At the end of the follow-up, the proportion of BCVA score improvements greater than 15 ETDRS letters was similar in patients with both forms of occlusions (measured in 45.5% of nonischemic and 45.8% of ischemic patients) (P=0.977). There were significant reductions in FT from baseline values to 230±40.50 μm (P=0.0001) in patients with nonischemic occlusions and 270±40.50 μm (P=0.0001) in patients with ischemic forms. There was a significant difference (P<0.03) in the number of IVB injections administered in patients with nonischemic C/HCRVOs (8.7±1.58) compared to patients with ischemic occlusions (9.7±1.78). NVG occurred in 2 cases of ischemic occlusions.


CONCLUSIONS
The 3-year IVB therapy provided sustained vision and FT gains in most phakic patients with acute C/HCRVOs, making this treatment option a rational and viable therapeutic strategy. Bevacizumab was more effective in patients with ischemic occlusions who required a significantly higher number of injections.