Drug delivery techniques for treating age-related macular degeneration

Abstract

Introduction: Currently, the standard therapy for neovascular age-related macular degeneration involves the use of anti-vascular endothelial growth factor (VEGF) drugs, which are delivered by repeated office-based intravitreal injections. This treatment is generally very effective in stabilizing or improving vision, although repeated injections create a burden for patients, family members and physicians. In addition, the cumulative risks of endophthalmitis and other complications increase with the number of injections.

Areas covered: In the clinic, much attention is focused on the relative efficacies of the three major anti-VEGF medications (bevacizumab, ranibizumab and aflibercept) as well as the most popular re-injection regimens (monthly, as-needed and treat-and-extend). In theory, intravitreal anti-VEGF drug delivery with sustained-release devices would offer similar visual results with fewer required re-injections. Various approaches have been studied, including noninvasive techniques, intraocular implants and colloidal carriers, such as liposomes, microparticles and nanoparticles.

Expert opinion: Despite its theoretical appeal, sustained-release drug delivery will not replace current techniques unless it offers one or more advantages in efficacy, safety, convenience or cost. Currently, many patients maintain stable vision with intravitreal injections at intervals of 2 months or longer, so sustained-release techniques will have to lengthen these intervals substantially to become widely accepted. As we continue to collect data from clinical trials, the role of sustained-release techniques will become better defined.

Keywords::

• age-related macular degeneration
• choroidal neovascularization
• intravitreal injection
• vascular endothelial growth factor

Declaration of interest

SG Schwartz has been a consultant for Alimera, Bausch + Lomb and Santen, and has received speakers fees from Regeneron and ThromboGenics. IU Scott has been a consultant for Alcon, FOVEA, Santen and ThromboGenics and has received speakers fees from Genentech. HW Flynn has been a consultant for Santen and has received speakers fees from Vindico. MW Stewart has served on the advisory boards for Allergan and Regeneron and has been a consultant for Boehringer-Ingelheim.

Notes

This box summarizes key points contained in the article.