Abstract
Introduction: :
Background:Geographic atrophy (GA) due to age-related macular degeneration (AMD) is a major cause of severe visual loss and represents a large unmet medical need. The purpose of this multicenter natural history study is to determine the rate of progression of GA lesions over time and to assess baseline characteristics that predict lesion growth rates.
Methods: :
Inclusion criteria include age ≥ 55 years, a single GA lesion of ≥0.5 disc area (DA), total lesion size ≤ 7 DA, best-corrected visual acuity (BCVA) of ≥35 letters and no evidence of choroidal neovascularization. Baseline evaluation included BCVA, fundus photography, confocal scanning laser ophtalmscopy fundus autofluorescence (FAF) imaging, and fluorescein angiography. FAF images and fundus photographs are obtained at 6 month intervals. The primary outcome measure is the enlargement rate of GA assessed with FAF imaging.
Results: :
Baseline data are available for 544 patients. The mean age of patients was 77.1 ± 7.7 years and mean BCVA was 61.6 ± 14.1 letters. GA was bilateral in 93% of patients. With FAF imaging lesions were multifocal in 74.3% of eyes, mean lesion size was 7.08± 4.94 mm2 at baseline and expanded by 1.73 ± 1.31 mm2 at Month-12. Lesion growth rates were significantly correlated with baseline lesion size (p=0.0001), lesion location (extra- vs. foveal; p<0.0034) and lesion complexity (uni- vs. multifocal; p<0.0005), but were not different between patients with uni- or bilateral GA. In agreement with the FAM study abnormal perilesional FAF patterns including none (4%), focal (4%), banded (5%), patchy (2%) and diffuse (65%) predicted lesion growth rates: in diffuse patterns GA enlargement rates were significantly greater than those of lesions with no or with focal patterns (p=0.0024).
Conclusions: :
The identification of patient and lesion characteristics that predict lesion growth rates will be helpful in designing future treatment trials to evaluate novel therapies for slowing progression of geographic atrophy.Clinical Trial: www.clinicaltrials.gov NCT00599846
Clinical Trial: :
www.clinicaltrials.gov NCT00599846
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: natural history • imaging/image analysis: clinical