By Jacqueline Katz
Macular degeneration, often referred to as age-related macular degeneration (AMD), is the leading cause of vision loss among elderly Americans. Of patients with AMD, between eighty and ninety percent of cases are of the dry, rather than the wet, variety. It is projected that AMD will affect approximately three million Americans by 2020, which is great impetus for the discovery of effective treatment for dry AMD.
In dry AMD, the retinal pigment epithelium (RPE) support cells in the macula, the functional center of the retina, perish. The RPE support light-sensitive photoreceptor cells. Consequently, as the RPE begin to die, so do these photoreceptors that are crucial to vision. As the macula is responsible for central vision, direct line of sight vision is lost while peripheral vision remains intact.
A team of UC Santa Barbara stem cell researchers recently published the preliminary results of a small-scale human clinical trial for dry AMD in which four patients received retinal implants of human embryonic stem cell-derived RPE delivered on a synthetic scaffold. These implants should, and did in one of the four patients, revive alive, but debilitated, photoreceptors and prevent the loss of additional cells. The end goal is implantation before vision loss to prevent the death of photoreceptors and, therefore, impending blindness.
While the study is just in its beginning stages, the researchers are enthused by the results thus far. However, the team also recognizes that they have a long way to go before they need to start hiring in the marketing department.
University of California - Santa Barbara. "Retinal implant designed to replace support cells damaged by dry age-related macular degeneration." ScienceDaily. ScienceDaily, 4 April 2018. <www.sciencedaily.com/releases/2018/04/180404143357.htm>.