Study shows steady progression of geographic atrophy and related vision loss

Am J Ophthalmol. 2008;146(5):692-699.

The first population-based study of 5-year changes in eyes with pure geographic atrophy showed a steady progression of pathology and vision loss.

"Population-based data show few ocular and medical factors related to the incidence of pure GA," the study authors said. "The natural history of pure GA has been described as progressive, going through stages and usually involving loss of vision over time."

Data were collected from patients participating in the Beaver Dam Study. ETDRS protocol was used to gauge best corrected visual acuity. Fundus photography centered on the retinal disc and fovea. Fifty-three eyes of 32 participants underwent at least one follow-up examination in which changes in AMD dimensions could be measured.

All 53 eyes showed progression of GA. The average 5-year increase in atrophy was 6.4 mm². Atrophy progressed to involve the foveal center in 47% of 19 eyes. Visual acuity decreased a mean 17 letters. Eyes with merged atrophic lesions had the largest area of atrophy and poorest vision; those with multifocal atrophic lesions had the smallest area of atrophy and best vision, the authors said.

"Inclusion of genetic factors and use of newer technologies that are more sensitive in detecting and measuring atrophy and pre-atrophy lesions may enable better characterization of GA lesions and of risk of progression," they said. "This will be important as new therapeutic interventions are developed for preventing visual loss in eyes with GA."