ABSTRACT
OBJECTIVE: To characterize the size, location, conformation, and features of incident geographic atrophy (GA) as detected by annual stereoscopic color photographs and fluorescein angiograms (FAs). DESIGN: Retrospective cohort study within a larger clinical trial. PARTICIPANTS: Patients with bilateral large drusen in whom GA developed during the course of the Complications of Age-related Macular Degeneration Prevention Trial (CAPT). METHODS: Annual stereoscopic color photographs and FAs were reviewed from 114 CAPT patients in whom GA developed in the untreated eye during 5 to 6 years of follow-up. Geographic atrophy was defined according to the Revised GA Criteria for identifying early GA.(23) Color-optimized fundus photographs were viewed concurrently with the FAs during grading. MAIN OUTCOME MEASURES: Size and distance from the fovea of individual GA lesions, number of areas of atrophy, and change in visual acuity (VA) when GA first developed in an eye. RESULTS: At presentation, the median total GA area was 0.26 mm(2) (0.1 disc area). Geographic atrophy presented as a single lesion in 89 (78%) eyes. The median distance from the fovea was 395 µm. Twenty percent of incident GA lesions were subfoveal and an additional 18% were within 250 µm of the foveal center. Development of GA was associated with a mean decrease of 7 letters from the baseline VA level compared with 1 letter among matched early age-related macular degeneration eyes without GA. Geographic atrophy that formed in areas previously occupied by drusenoid pigment epithelial detachments on average were larger (0.53 vs. 0.20 mm(2); P = 0.0001), were more central (50 vs. 500 µm from the center of the fovea; P<0.0001), and were associated with significantly worse visual outcome (20/50 vs. 20/25; P = 0.0003) than GA with other drusen types as precursors. CONCLUSIONS: Incident GA most often appears on color fundus photographs and FAs as a small, singular, parafoveal lesion, although a large minority of lesions are subfoveal or multifocal at initial detection. The characteristics of incident GA vary with precursor drusen types. These data can facilitate design of future clinical trials of therapies for GA. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Subject(s)
Geographic Atrophy/diagnosis , Macular Degeneration/complications , Retinal Pigment Epithelium/pathology , Vision Disorders/diagnosis , Aged , Aged, 80 and over , Female , Fluorescein Angiography , Geographic Atrophy/etiology , Geographic Atrophy/physiopathology , Humans , Laser Coagulation , Low-Level Light Therapy , Macular Degeneration/prevention & control , Male , Middle Aged , Photography , Retrospective Studies , Vision Disorders/etiology , Vision Disorders/physiopathology , Visual Acuity/physiologyABSTRACT
PURPOSE: To evaluate new grading criteria for geographic atrophy (GA), as detected by annual stereoscopic color fundus photographs and fluorescein angiograms, and to assess whether application of the revised criteria provides earlier identification of GA than previous criteria involving only color fundus photography. METHODS: Annual fundus image sets from 114 CAPT patients who developed GA in the untreated eye during 5 to 6 years of follow-up were reassessed for the presence of GA, using revised grading criteria, in which GA was defined by (1) the presence of hyperfluorescence on fluorescein angiography; and (2) at least one other characteristic indicative of involution of the retinal pigment epithelium (i.e., sharp edges, excavation of the retina, or visible choroidal vessels on either color images or fluorescein angiograms). Reliability and time of initial detection of GA using the revised criteria were assessed. RESULTS: The revised criteria are reliable (97.8% intragrader, 93.3% intergrader agreement) and accurate (false-positive rate, 0.8%) for detecting individual early GA lesions. Using this revised method, individual GA lesions were identified 1-year earlier on average than was possible with criteria used in previous CFP studies. The use of two imaging modalities was more sensitive in detecting GA and its features than either imaging modality alone (P ≤ 0.0001). CONCLUSIONS: Early GA areas can be reliably identified when defining criteria are based on both color photographs and fluorescein angiograms. These methods can be used to investigate the natural history of GA earlier in the course of disease than previously possible and to facilitate the design of future clinical trials of treatments for GA. (ClinicalTrials.gov number, NCT00000167).
