Maryam Zekavat, MD, PhD
Mass Eye & Ear
At the Retina Society 2025 meeting in Chicago, the two late-breaking sessions highlighted innovations in retinal stem cell and prosthetic technologies for central vision improvement in individuals with geographic atrophy.
First, Rajesh Rao presented new data showing the promise of RPE-stem cells (RPESC) injected as a subretinal bleb after vitrectomy for eyes with dry AMD with vision between 20/70 to 20/800. These RPESC self-renew and differentiate into RPE cells over several weeks, and as showed in a recent paper, they exhibit key physiological characteristics of native tissue (Blenkinsop et al. Retinal Cell Biology). Across the first cohort of six subjects receiving low-dose 50,000 RPESC, there was a good safety profile and the procedure overall was well tolerated, with no vision loss, no tumor formation, no significant inflammation, and no ERM formation. Importantly, on post-operative month 1, the treated eye on average gained 21 letters versus a -1.3 letter loss in the untreated eye. While the study was limited given the small number of subjects and that procedures were done by one surgeon at a single clinical site, they are overall promising. The study results will be published soon in Cell: Stem Cell, and the trial is ongoing.
Second, Joseph Martel presented data on the PRIMA retinal implant in patients with geographic atrophy. The PRIMA retinal implant is a 2mm-wide, 30um thick wireless prosthesis which replaces the outer retina, interacts with bipolar cells, and is connected to a visual interphase which allows the patient to process the world through transparent glasses. There have been three clinical trials testing this prosthetic system across individuals with geographic atrophy, including the two feasibility studies in France (5 patients, 72 month followup) and USA (4 patients, 36 month followup), and the pivotal multicenter study PRIMAvera (38 subjects, 36 month followup). Excitingly, the PRIMAvera trial 1 year results showed a mean improvement of 23 letters across individuals with the best patient improving by 59 letters. Overall, the results suggest that integration of natural and artificial vision is possible with meaningful improvement in VA and reassuring safety and implant stability signals.
In summary, the future of vision improvement in individuals with geographic atrophy, across both retinal stem cell and prosthetic technologies, is bright. Further trials with larger sample sizes will help translate these technologies for use in patient care.