Age-related macular degeneration (ARM) is a major cause of vision loss in the elderly. It is thought that smoking and diet may contribute to the risk of developing the condition but it is clear that heredity plays a major role. Variations in two genes, CFH and HTRA1/ARMS2, have been found to strongly contribute to the risk of developing ARM, but there are additional genes that influence a person's chances of having this condition and how they will progress to vision loss. We are investigating these genetic variations that contribute to ARM so that we can eventually understand the causes of this complex condition. We study the genetic variations (SNPs) that are shared among ARM-affected individuals within families as well as compare the frequencies of genetic variations in ARM-affected individuals with those in unaffected persons who are matched in age, gender, and exposures. We are conducting studies with the DNA from our previous cohort of research participants as well as developing a prospective study of high-risk family members and their spouses to evaluate genetic risks and presymptomatic retinal changes. Our long-term goals are to develop new preventive therapies that can slow or halt the development of this disease and to be able to provide these treatments to those who are at greatest risk before they experience vision-threatening changes.