Researchers at the John A. Moran Eye Center’s Sharon Eccles Steele Center for Translational Medicine (SCTM) are leading a global race to find new ways to treat or even cure a top cause of blindness among older adults.
Age-related macular degeneration (AMD) affects close to 200 million people worldwide and causes between 15 and 20 percent of irreversible vision loss for people over 50 in Europe and North America. Over the past decade, SCTM researchers have clarified the genetics of AMD, refined the clinical understanding of its natural course of progression, and developed potential new treatments, including a gene therapy now in clinical trials.
Publishing in the prestigious journal Nature Communications, the SCTM’s latest AMD research points the field away from a liver-produced protein others had identified as a promising therapeutic target. Studying a group of 14,965 healthy subjects and 20,741 AMD patients, SCTM scientists determined FHR-4 is not independently associated with AMD and does not influence its course of progression.
“Targeting FHR-4 is unlikely to be an effective therapeutic strategy,” said lead author Moussa Zouache, PhD. “This is important information as so many scientists at institutions and companies are dedicating large resources to design therapies based on FHR-4 against such a blinding and often hereditary disease. We and other AMD researchers are now in a better place to identify proteins that are definitively involved in AMD and explore their potential for therapeutics.”
AMD can be difficult to study since there are no animal models of the disease, leaving researchers to work with human tissue. This discovery would not have been possible without the world-leading resources that the SCTM houses. These include the world’s largest donor eye tissue repository of its kind, with 10,000 eyes available for scientists to compare healthy and diseased tissue. A study pairs this tissue with donor genotypes and medical records.
The SCTM also hosts one of the largest ongoing clinical studies of AMD, with more than 4,500 subjects and patients followed over the past 15 years or more.
These unique resources have allowed the SCTM, directed by Gregory S. Hageman, PhD, to change our understanding of the disease. The team has demonstrated that a cluster of genes on chromosome 1 causes one form of AMD, while a pair of genes on chromosome 10 causes a second form. Collectively, these genes account for more than 90 percent of the risk of developing AMD. The team is pursuing a therapeutic strategy to treat both forms of AMD.
The latest paper is “Levels of complement factor H-related 4 protein do not influence susceptibility to age-related macular degeneration or its course of progression.”