08/27/2026
CRF Chief Scientific Officer Update: PRIMA2, A New Frontier in Vision Restoration
Many in the choroideremia (CHM) community have recently asked about PRIMA2, a retinal implant being developed to restore a degree of vision for people with advanced retinal disease. The Choroideremia Research Foundation (CRF) recently spoke with leaders from Science Corporation, the company developing PRIMA2, to learn more about the technology and its potential relevance to people with CHM.
Our Chief Scientific Officer, Mike McConnell, PhD, shares his perspective:
At a fundamental level, vision is what your brain constructs from the electrical signals it receives from the retina. The challenge facing vision prosthetic scientists has been to convert the light in our environment into a series of electrical signals that the brain can interpret as vision. In July, Science Corporation received European approval for their PRIMA2 device, which solves this challenge. The US FDA is expected to weigh in soon too.
PRIMA2 has two components, glasses and a retinal implant. No wires or batteries. The same environmental light that’s being interpreted for vision powers everything. Tested first in AMD patients with geographic atrophy and very low vision, 80% of patients could read numbers, letters, and words with an average of 5 lines of improvement on the vision chart. Some of these patients could report “That’s an A” as soon as the device was turned on.
A simulator of what these patients see is available at: prima.science.xyz. This illustrates black-and-white vision in the center of the visual field and the ability to read the number and suit of playing cards.
CRF learned more about the potential for CHMers with little or no light perception. Because AMD and CHM progress differently (i.e., inside-out vs. outside-in), the outcome of ongoing trials in retinitis pigmentosa (RP) patients should provide more meaningful guidance for CHMers. CRF will keep you updated!
I think of CRF priorities in three buckets: prevent CHM, stabilize CHM, and restore vision to late-stage CHMers. The majority of our funded research programs address the first two buckets because visual prosthetics have been the stuff of Star Trek and science fiction. With Science Corporation’s PRIMA2, the central technology for prosthetic vision is no longer fiction, it exists and it does what it does.
It is too early to get very excited, but it is clear that the vision restoration bucket is beginning to hold some water.
Read the full recent reporting on European approval of PRIMA2 from BrightFocus Foundation: https://www.brightfocus.org/resource/prima-implant-brings-vision-restoration-within-reach
Now available in Europe, the PRIMA implantable device may help improve vision in advanced age-related macular degeneration. Learn how it works and when it could be available in the U.S.
