CIRM funds many projects seeking to better understand diseases of blindness and to translate those discoveries into new therapies.
Nearly a million Americans are blind, with another 2.4 million suffering significant visual impairment. While there are several causes of blindness, the leading cause of all visual impairment is age-related macular degeneration, which affects 1.7 million Americans.
California’s stem cell agency funds research into potential therapies for three of the causes of blindness. All the research teams are seeking to use various forms of stem cells to rescue or replace cells in the eye damaged or threatened by the diseases. Several groups are working on ways to restore vision for people with age-related macular degeneration (AMD). Other projects are looking to preserve vision in patients with retinitis pigmentosa, and to restore clarity to the surface of eyes impacted by corneal disease.
In AMD the layer of cells that support the photoreceptors is destroyed. Without this support system, the photoreceptors, the cells that actually allow us to sense light start to malfunction. CIRM-funded teams are looking at various methods of replacing this layer of support cells called RPE (retinal pigment epithelial) cells. Some are using embryonic stem cells as a starting point to generate new RPE cells. Others are using stem cells obtained by reprogramming adult cells to be like embryonic cells, which could potentially come from the patients’ themselves.
Retinitis pigmentosa, an inherited and progressive vision loss that leaves most patients legally blind by mid-life, directly destroys the photoreceptors. CIRM-funded researchers are seeking to use stem cells to rescue the receptors from further damage and potentially replace them with new ones.
Limbal Stem Cell Deficiency
The cornea, the outer surface of the eye, is constantly refreshed by stem cells that reside in neighboring tissue. But some people just don’t have enough of these stem cells, called Limbal stem cells, to make enough new cornea cells. CIRM-funded researcher are trying to correct this condition, limbal stem cell deficiency, by retrieving the few existing limbal stem cells, and using various techniques to expand them in the laboratory until there are enough cells to rebuild a healthy cornea.
Some projects we fund are trying to take promising therapies out of the laboratory and closer to being tested in people. These Disease Team Awards encourage the creation of teams that have both the scientific knowledge and business skills needed to produce therapies that can get approval from the Food and Drug Administration (FDA) to be tested in people. In some cases, these awards also fund the early phase clinical trials to show that they are safe to use and, in some cases, show some signs of being effective.
Disease Team Awards
University of Southern California
This team is using embryonic stem cells to produce the support cells, or RPE cells, needed to replace those lost in AMD. Because these cells exist in a thin sheet in the back of the eye, they are assembling these sheets in the lab by growing the RPE cells on synthetic scaffolds. These sheets are then surgically implanted into the eye. They are testing the human embryonic stem cell-derived RPE cells in a Phase 1/2a clinical trial to treat the advanced dry form of AMD.
University of California, Irvine
For retinitis pigmentosa, the team plans to use donor tissue to isolate cells that are part way down the path from neural stem cells to adult eye tissue. These retinal progenitor cells would be grown in large quantities in the lab and then injected into the eye. The team suggests the cells could help in two ways. They may be able to protect the photoreceptors not yet damaged by the disease, and they may be able to form new photoreceptors to replace those already lost. The team is testing the safety of transplanting human retinal progenitor cells into patients with RP in a phase 1/2 clinical trial.
Mark Humayun, who leads the USC disease team, discusses his approach to treating macular degeneration
CIRM Grants Targeting Vision Loss
CIRM Macular Degeneration Videos
News and Information
- The Stem Cellar's entries on macular degeneration research
- Sights on a Cure: Stem cell scientists have macular degeneration in the crosshairs (CIRM)
- Living with Macular Degeneration: Sharon Hayes (CIRM)
- National Eye Institute: Macular Degeneration Facts
- Find a clinical trial near you: NIH Clinical Trials database
- Macular Degeneration Association
- American Macular Degeneration Foundation
- The Macula Foundation
- Stem Cell Netword eye disease page
- Foundation Fighting Blindness
- Lighthouse for the Blind
- Family Caregiver Alliance
- National Family Caregivers Association