Role of ranibizumab in management of macular degeneration

Age-related macular degeneration (AMD) is one of the most common causes of severe vision loss in the western world. Both animal and human studies have established that vascular endothelial growth factor (VEGF) plays an important role in the pathogenesis of this process. Ranibizumab (Lucentis(TM), Genentech, South San Francisco, CA) is a monoclonal antibody fragment (Fab) directed toward all isoforms of VEGF-A that was specifically designed to target wet AMD. The human antibody fragment is produced by an E. coli expression system and has a molecular weight of 48kD allowing for excellent retinal penetration. The most common ocular complaints of patients receiving ranibizumab injections in randomized clinical trials were transient conjunctival hemorrhage, vitreous floaters, intraocular inflammation, increased intraocular pressure and eye pain. The rates of serious adverse events such as retinal detachment, cataract and endophthalmitis were similar to those that have been reported with other intravitreal injections and patients should always be treated under strict aseptic conditions to reduce this risk. There were no significant non-ocular events found during any study so far and the risk of thromboembolic events was less than 4% and not different than sham. The MARINA, ANCHOR and PIER studies validated the safety and efficacy of ranibizumab amongst a large population with different choroidal neovascular membrane lesion types against sham or standard of care treatment. These studies recommended monthly intravitreal ranibizumab for patients. However, the PIER study reported that an alternative dosing of every three months is acceptable but less effective than monthly injections.