Genetic factors Accelerating Progression to Advanced AMD
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in older adults in the United States. The factors that determine progression from early AMD (with little vision loss) to advanced AMD (with more severe vision loss) are poorly understood. We will use detailed clinical examinations of the eye and large-scale genetic analysis to identify new genetic factors that are associated with changes in the eye over time and with development of advanced AMD. The results of this study will improve our understanding of the AMD disease process and provide potential avenues for development of targeted therapies.
The goal of our project is to identify genetic factors that influence progression of age-related macular degeneration (AMD) from early stages (where vision loss is less severe) to late stages (where there is significant visual impairment). Our study builds on an existing group of 400 individuals with early AMD who have been followed for at least two years and have had genetic factors measured across the genome. The first aim of our project is to analyze ocular coherence tomography (OCT) images taken at our first study visit (the "baseline exam") where early AMD was detected. These images will be evaluated for several features that might predict progression to more severe disease, and these features will be examined for association with genetic factors. In the second specific aim, we will examine these baseline OCT features for association with the time that it takes to progress to late AMD. We will also determine if the influence of these OCT features on progression is modified by genetic factors. Identifying measurable factors that predict progression to late AMD might help us design tailored clinical follow-up strategies (more frequent visits for those most at risk of progression, for example). Identifying genetic factors that predict faster or slower progression could also provide targets for the development of potential therapies.
About the Researcher
Dr. William K. Scott is professor of Human Genetics and Public Health Sciences, and vice-chair for Education & Training in the Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics at the University of Miami Miller School of Medicine. His research focuses on the identification of gene and environment interactions that influence risk of complex diseases, including infectious diseases, such as tuberculosis and Staphylococcal bacteremia; neurodegenerative diseases, such as Parkinson and Alzheimer disease; and eye diseases such as age-related macular degeneration and glaucoma. He is the program director for the NEI-funded Ocular Genomics Training Program (T32) and the Master of Science in Genomic Medicine program, and is the executive director of the University of Miami Brain Endowment Bank.
Like many children, my favorite question was "Why?" My mother suggested that would make me a good scientist--and that idea stuck with me throughout my education. I always have wanted to be a scientist and have never stopped asking "Why?" I tell my students (and any younger person with interests in science) that answering that question is the most interesting part of the job, and that sometimes, right after a discovery, you are the only person who knows the answer to that question. And that is my daily motivation--the hope that this is the day I'll answer my favorite question.
With this study, we are trying to answer the question "Why do some people develop early age-related macular degeneration but never progress further, and others move rapidly to late stages with severe vision loss?" If we can figure out what factors predict progression (or lack of it), we might be able to design strategies to keep people from developing severe visual impairment. We hypothesize that genetic factors play a role, as many have already been discovered that determine lifetime risk of late AMD, and yet our work so far suggests that these factors might be different from the ones already discovered. Answering this question requires us to shift our existing genetics study in a new direction -- which requires additional preliminary data to support an application to NIH for a larger study. The funding from the BrightFocus Foundation has enabled us to conduct this preliminary study, and we are grateful to the Foundation and its donors for this support.
First published on: September 26, 2018
Last modified on: June 22, 2020