Once the retinal pigment epithelium (RPE) is lost and the macula begins to degenerate, vision loss isn’t far behind. However, RPE replacement strategies may delay the disease’s progression or even restore lost vision, researchers say. That may seem like a lofty claim, but according to new research published in the April issue of Science Translational Medicine, a bioengineered RPE monolayer is proving to do just that. In a phase 1/2a study that looked at five subjects, none showed progression of vision loss, one eye improved by 17 letters and two eyes demonstrated improved fixation.1

These functional changes were not the only improvements researchers noted. Physical structural changes were evaluated as well. According to optical coherence tomography imaging, all the subjects’ implants successfully integrated with the already-existing photoreceptors. This combination of functional and structural findings, the researchers said, suggests that the implant may improve visual function, at least in the short term, in some patients with severe vision loss from advanced dry age-related macular degeneration (AMD).1

The California-based research team developed the clinical-grade retinal implant themselves from a human embryonic stem cell–derived RPE grown on an ultrathin, synthetic parylene substrate designed to mimic Bruch’s membrane.1 

While patients with neovascular or “wet” AMD have the option of anti-VEGF injections, dry AMD patients currently have no effective treatments. According to the National Eye Institute, by 2050, 5.44 million Americans will have some form of the sight-threatening disease; approximately 90% will have dry AMD.2,3

1. Kashani A, Lebkowski J, Rahhal F. A bioengineered retinal pigment epithelial monolayer for advanced, dry age-related macular degeneration. Science Translational Medicine. Apr 2018;10(435):eaao4097.
2. The Eye Diseases Prevalence Research Group - National Eye Institute. Prevalence of age-related macular degeneration in the United States. Archives of Ophthalmology. 2004;122(4):564-572.
3. American Macular Degeneration Foundation. Dry vs. Wet Age-Related Macular Degeneration. www.macular.org/dry-vs-wet-macular-degeneration. Accessed May 4, 2018.