Grant will allow examination of cellular changes in the retina that increase susceptibility to the disease.
UC Davis researchers have been awarded a three-year, $1.8 million grant from the National Eye Institute to study the cellular changes that cause age-related macular degeneration (AMD), the leading cause of vision impairment among older Americans.
“This disease does not appear until between the ages of 55 and 60, and the prevalence grows dramatically with chronological age,” said Larry Hjelmeland, UC Davis professor of ophthalmology with the UC Davis Eye Center and principal investigator on the grant. “We want to know the biochemical changes in retinal cells that occur with aging and increase the susceptibility for this disease.”
AMD, which affects more than 1.75 million people in the U.S., is characterized by damage to the retina, the light-sensitive tissue that lines the inner surface of the eye. It results in loss of vision in the center of the visual field. Dry macular degeneration, the most common form of the disease, results in gradual vision loss and is usually less severe. The wet form of the disease is characterized by the growth of abnormal blood vessels, which leak fluid and blood into the macula and obscure vision.
Both forms of AMD can lead to vision loss that impedes mobility and independence. Many patients are unable to drive, read, recognize faces or perform tasks that require hand-eye coordination. Treatment options have improved in recent years, but there is no cure.
With the new funding, Hjelmeland and Zeljka Smit-McBride, co-principal investigator on the grant and an associate project scientist with the UC Davis Eye Center, will look at how the retinal pigment epithelium (RPE), a protective layer of cells just outside the retina, is affected by epigenetic factors — changes that alter gene expression while leaving the original genome sequence intact. Preliminary research by the team showed that the expression in several genes important to RPE cells changes with age.
“Looking at aging as an epigenetic phenomenon clearly represents a big step forward for the study of AMD,” said Hjelmeland, whose project is one of the first to be funded by the National Eye Institute to explore the link between epigenetics and eye disease.