12 Jan Age-Related Macular Degeneration: Ten Year Follow Up Study
Emily Y. Chew, M.D.
Deputy Director, Division of Epidemiology and Clinical Applications
National Eye Institute
National Institutes of Health (NIH), Bethesda, MD
MedicalResearch.com: What are the main findings of the study?
Dr. Chew: We provided 10 year rates of development of advanced age-related macular degeneration (AMD), either neovascular (NV) AMD or central geographic atrophy (CGA). We also presented the risk factors associated with progression to advanced AMD. These risk factors that were associated with an increased risk of progression included drusen status at baseline (small drusen, intermediate, large drusen), presence of advanced AMD in the fellow eye, increasing age, female gender, smoking, and the white race.
This is the last cohort of patients in whom anti-vascular endothelial growth factor agents were not available during the course of the study. The natural history of the vision loss for those who developed advanced is relentless, more gradual in those with geographic atrophy than neovascular AMD, and may occur even 1 year prior to the detection of advanced AMD by stereoscopic fundus photographs in obtained at study visits.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Chew: We knew that the presence of large drusen increased the risk of developing advanced AMD. However, we found that 36% of participants with medium sized drusen in one eye and 71% of those with bilateral medium sized drusen at baseline would develop large drusen by 10 years.
The risk of developing advanced AMD by 10 years was very low in participants with no drusen and in those with small drusen at baseline but 14% of participants with medium drusen in both eyes at enrollment developed advanced AMD by 10 years.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Chew: The risk of progression to advanced AMD, neovascular or central geographic atrophy was increased in persons with large drusen, AMD retinal pigmentary changes, presence of advanced AMD in the fellow eye. In addition, medium sized drusen may be another important risk for potential progression to advanced AMD. The visual acuity loss is relentless once advanced AMD develops.
What recommendations do you have for future research as a result of this study?
Dr. Chew: We hope the progression rates found in this study will help facilitate future clinical research, both epidemiologic studies and clinical trials by providing accurate information for sample size calculations and for evaluation of risk factors. Early AMD consisting of medium sized drusen may be an important stage for future evaluations of therapies. We look forward to using other modalities of imaging to give us data on progression rates of AMD.