14 DAY TRIAL // A UC Irvine assistant professor of ophthalmology is on the road to success with a stem cell-based therapy for retinitis pigmentosa, a genetic eye condition that affects millions of Americans and people worldwide.
For the past 25 years, Dr. Henry Klassen has been focusing on regenerating damaged retinal tissue so that people suffering from retinitis pigmentosa and macular degeneration could regain their sight.
Also, the doctor believes that “the eye is an important proving ground for stem cell-based therapies.”
Last October, he received $3.85 million from the California Institute for Regenerative Medicine, so that he could develop a standard method for creating photoreceptor progenitor stem cells from immature retinas and transplanting them into the eye to repair or replace damaged light-sensing cells.
The goal of this research is to introduce stem cells that will take the place of damaged, dying rods and revive moribund cones, reversing the evolution of retinitis pigmentosa, even if the condition is at a relatively advanced stage, and this CIRM funding should make clinical trials a possibility within three years.
“We believe it’s possible to replace rods and rejuvenate cones in the degenerated retina,” said Klassen.
“Our methods have been validated, and I’m optimistic that stem cell-based treatments can help people with eye diseases restore their fading vision.”
Retinitis pigmentosa manifests itself by a slow decay of the photoreceptors – shaped like rods and cones, that perform the initial detection of light.
The mutations in genes that are important for photoreceptor function are what cause the disease, and eventually the rods die, followed by the cones.
People suffering from the condition first experience night blindness, followed by tunnel vision and then legal blindness.
In his research, Dr Klassen is discovering new ways that stem cells can be used to fix the retina, which is actually the only part of the body’s intricate central nervous system that can be seen without surgery.
By doing so, Klassen is gathering information about stem cells that goes beyond eye disease.
He says that “the eye is an important proving ground for stem cell-based therapies, and provides a stepping stone to many otherwise incurable diseases of the brain and spinal cord.”
For Dr. Klassen, the eyes provide exceptional access to the central nervous system, because besides his medical degree, the researcher holds a doctorate in neurobiology.
And since the retina lines the inner surface of the eye and converts light images into nerve impulses that are sent to vision centers in the brain, understanding its architecture can open the way to the neural system.
Klassen received this grant because the CIRM reviewers gave his proposal the highest scientific score – 93 on a scale of 100, among all applicants.
Ingrid Caras, a CIRM science officer, said that “stem cell research on the eye is moving quite quickly.
“The eye is an attractive study target – it’s a small, contained area with no immune rejection of implanted cells, and it’s much easier to monitor what’s happening in the eye.”
Henry Klassen is also a research director for the retinal regeneration program at UCI’s Gavin Herbert Eye Institute and is affiliated with the Sue & Bill Gross Stem Cell Research Center.
The Discovery Eye Foundation also supports his work.
