Mortality associated with bevacizumab intravitreal injections in age-related macular degeneration patients after acute myocardial infarct: a retrospective population-based survival analysis

The propensity score is the probability of treatment assignment conditional on observed baseline characteristics. The propensity score allows one to design and analyze an observational (nonrandomized) study so that it mimics some of the particular characteristics of a randomized controlled trial. In particular, the propensity score is a balancing score: conditional on the propensity score, the distribution of observed baseline covariates will be similar between treated and untreated subjects. I describe 4 different propensity score methods: matching on the propensity score, stratification on the propensity score, inverse probability of treatment weighting using the propensity score, and covariate adjustment using the propensity score. I describe balance diagnostics for examining whether the propensity score model has been adequately specified. Furthermore, I discuss differences between regression-based methods and propensity score-based methods for the analysis of observational data. I describe different causal average treatment effects and their relationship with propensity score analyses.

To describe effects of ranibizumab and bevacizumab when administered monthly or as needed for 2 years and to describe the impact of switching to as-needed treatment after 1 year of monthly treatment. Multicenter, randomized clinical trial. Patients (n = 1107) who were followed up during year 2 among 1185 patients with neovascular age-related macular degeneration who were enrolled in the clinical trial. At enrollment, patients were assigned to 4 treatment groups defined by drug (ranibizumab or bevacizumab) and dosing regimen (monthly or as needed). At 1 year, patients initially assigned to monthly treatment were reassigned randomly to monthly or as-needed treatment, without changing the drug assignment. Mean change in visual acuity. Among patients following the same regimen for 2 years, mean gain in visual acuity was similar for both drugs (bevacizumab-ranibizumab difference, -1.4 letters; 95% confidence interval [CI], -3.7 to 0.8; P = 0.21). Mean gain was greater for monthly than for as-needed treatment (difference, -2.4 letters; 95% CI, -4.8 to -0.1; P = 0.046). The proportion without fluid ranged from 13.9% in the bevacizumab-as-needed group to 45.5% in the ranibizumab monthly group (drug, P = 0.0003; regimen, P 0.60). The proportion of patients with 1 or more systemic serious adverse events was higher with bevacizumab than ranibizumab (39.9% vs. 31.7%; adjusted risk ratio, 1.30; 95% CI, 1.07-1.57; P = 0.009). Most of the excess events have not been associated previously with systemic therapy targeting vascular endothelial growth factor (VEGF). Ranibizumab and bevacizumab had similar effects on visual acuity over a 2-year period. Treatment as needed resulted in less gain in visual acuity, whether instituted at enrollment or after 1 year of monthly treatment. There were no differences between drugs in rates of death or arteriothrombotic events. The interpretation of the persistence of higher rates of serious adverse events with bevacizumab is uncertain because of the lack of specificity to conditions associated with inhibition of VEGF. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

To report the short-term safety, biologic effect, and a possible mechanism of action of intravitreal bevacizumab in patients with neovascular age-related macular degeneration (AMD). Interventional, consecutive, retrospective case series. Eighty-one eyes of 79 patients with subfoveal neovascular AMD. Patients received intravitreal bevacizumab (1.25 mg) on a monthly basis until macular edema, subretinal fluid (SRF), and/or pigment epithelial detachment (PED) resolved. Ophthalmic evaluations included nonstandardized Snellen visual acuity (VA), complete ophthalmic examination, fluorescein angiography, and optical coherence tomography (OCT). Assessments of safety, changes in Snellen VA, OCT retinal thickness, and angiographic lesion characteristics were performed. No significant ocular or systemic side effects were observed. Most patients (55%) had a reduction of >10% of baseline retinal thickness at 1 week after the injection. At 4 weeks after injection, 30 of 81 eyes demonstrated complete resolution of retinal edema, SRF, and PEDs. Of the 51 eyes with 8 weeks' follow-up, 25 had complete resolution of retinal thickening, SRF, and PEDs. At 1, 4, 8,and 12 weeks, the mean retinal thickness of the central 1 mm was decreased by 61, 92, 89, and 67 mum, respectively (P<0.0001 for 1, 4, and 8 weeks and P<0.01 for 12 weeks). At 4 and 8 weeks, mean VA improved from 20/200 to 20/125 (P<0.0001). Median vision improved from 20/200 to 20/80(-) at 4 weeks and from 20/200 to 20/80 at 8 weeks. Short-term results suggest that intravitreal bevacizumab (1.25 mg) is well tolerated and associated with improvement in VA, decreased retinal thickness by OCT, and reduction in angiographic leakage in most patients, the majority of whom had previous treatment with photodynamic therapy and/or pegaptanib. Further evaluation of intravitreal bevacizumab for the treatment of choroidal neovascularization is warranted.