Key Points
- The severity scale is a patient-based scale that includes both eyes of each patient. It considers the presence of large drusen
and pigmentary changes.
- Vision loss was associated with the fundus lesions of advanced AMD, including neovascularization features and geographic atrophy.
Dr. Chew
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Bethesda, MD—The Simplified Age-Related Eye Disease Study (AREDS) Age-Related Macular Degeneration (AMD) Severity Scale has been shown
to be predictive of vision loss in this patient population. Vision loss was associated with the fundus lesions of advanced
AMD, including neovascularization features and geographic atrophy, according to Emily Y. Chew, MD.
"Fundus lesions can be used as outcomes in prevention studies for the development of advanced AMD and may alleviate the need
for fluorescein angiography in large studies," said Dr. Chew. She is deputy director of the Division of Epidemiology and Clinical
Research, National Eye Institute, National Institutes of Health, Bethesda, MD.
The well-known AREDS, which began in 1992, evaluated the clinical course and prognosis of AMD and lens opacities of 4,757
men and women who were aged 55 to 80 years at enrollment in a randomized, controlled clinical trial of antioxidant vitamins
and minerals. The clinical trial ended in 2001, and 3,687 participants were followed until 2005.
10-year reviewThe purpose of the presentation was two-fold: to assess the 10-year risk of visual acuity (VA) loss in participants who developed
fundus lesions associated with advanced AMD and to assess the risk in each of the stages of the severity scale, Dr. Chew said.
The fundus lesions associated with neovascular AMD that were evaluated included serous detachments of the sensory retina,
non-drusenoid retinal pigment epithelial (RPE) detachments, subretinal or sub-RPE hemorrhages, and subretinal fibrosis. Other
lesion of advanced AMD evaluated was geographic atrophy that involved the center of the macula.
Various groups were identified within the study population:
- Eyes that had no or few drusen at baseline, did not progress to advanced AMD, and in which the VA level remained unchanged
during the course of the study. At baseline, there were 2,062 eyes with 20/20 vision. The 1,238 eyes that were followed at
10 years had a median VA of about 20/30.
- Eyes that had large drusen at baseline and did not progress to advanced AMD also maintained relatively good vision. At baseline,
there were 1,288 such eyes with about 20/30 vision. At the 10-year follow-up, 651 eyes had about the same level of vision.
"A total of 685 eyes had any neovascular AMD event," said Dr. Chew. "The first time neovascularization was observed, it could
be one or more of the fundus lesions present in an eye." In those eyes, the baseline VA was 20/32. The VA level decreased
to about 20/160 at the 5-year time point and to about 20/300 at the 10-year time point.
Further analyses then evaluated each fundus lesion separately. In the group of 519 patients who had a serous subretinal or
hemorrhagic retinal detachment, the median VA at baseline of 20/32 declined to about 20/200 at the 5-year examination and
about 20/300 at the 10-year time point, Dr. Chew said.
In 302 patients with subretinal fibrosis, a more rapid decline in VA was seen over time, with the median baseline VA dropping
from 20/40 to 20/320 at the 5-year time point and again at the 10-year time points.
The development of central geographic atrophy (428 eyes) resulted in the VA decline from a median baseline value of 20/40
to 20/160 at the 5-and 10-year time points.
