The Efficacy, Safety, and Efficiency of the Off-Label Use of Bevacizumab in Patients Diagnosed With Age-Related Macular Degeneration: Protocol for a Systematic Review and Meta-Analysis
Authors: Estarreja João , Mendes Priscila , Silva Carina , Camacho Pedro , Mateus Vanessa 
Published: March 2023

Background
Age-related macular degeneration (AMD) is recognized as the leading cause of vision loss in older people. Considering the phenomenon of aging societies worldwide, the prevalence of AMD is expected to increase gradually in the future. AMD can be divided into early, intermediate, and late stages, with the early and intermediate stages being mainly asymptomatic, and the late stage being classified as geographic atrophy, neovascular AMD, or both. Current pharmacological treatments for neovascular AMD include anti–vascular endothelial growth factor agents, such as ranibizumab, pegaptanib, and aflibercept. Additionally, it has been reported that the off-label use of intravitreally administered bevacizumab is effective. It is also lower cost than other agents, which makes it an interesting pharmacological approach.

Objective
This review aims to evaluate the efficacy, safety, and efficiency of bevacizumab for the treatment of neovascular AMD.

Methods
This review will only consider randomized controlled clinical trials that compare the use of bevacizumab with another pharmacological agent or a placebo in patients aged 50 years and older who are diagnosed with vascular AMD. It will exclude studies that include participants diagnosed with polypoidal choroidal vasculopathy or retinal angiomatous proliferation. To identify and select relevant articles, we will develop a highly sensitive search strategy and apply it in MEDLINE via the PubMed platform. Upon selection of the studies and analysis of the titles, abstracts, and full texts, the results will be presented according to the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The analysis and extraction of the data will be performed by 2 independent reviewers. Risk of bias will be evaluated with the Critical Appraisal Skills Programme (CASP) checklist. Finally, the same reviewers will also perform a quality assessment of the included studies with the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) tool.

Results
The search strategy, after the application of the inclusion and exclusion criteria, identified 15 randomized clinical trials, which are currently being analyzed. This project has no funding and it has been developed by a multidisciplinary research team of pharmacologists and orthoptists. The study was initiated in May 2021 and it is expected to conclude by the end of 2023.

Conclusions
This review will provide a synthesis of current information and underlying evidence about the off-label use of bevacizumab in neovascular AMD. It will provide a clearer vision of a possible new pharmacological approach, as well as the most suitable treatment designs, for the treatment of neovascular AMD.

Trial Registration
PROSPERO CRD42021244931; https://tinyurl.com/p6m5ycpk

International Registered Report Identifier (IRRID)
DERR1-10.2196/38658