title: Natural History of Geographic Atrophy Progression Secondary to Age-Related Macular Degeneration (Geographic Atrophy Progression Study).
abstract: OBJECTIVE
  The Geographic Atrophy Progression (GAP) study was designed to assess the rate of geographic atrophy (GA) progression and to identify prognostic factors by measuring the enlargement of the atrophic lesions using fundus autofluorescence (FAF) and color fundus photography (CFP).
  
  
  METHODS
  Prospective, multicenter, noninterventional natural history study.
  
  
  METHODS
  A total of 603 participants were enrolled in the study; 413 of those had gradable lesion data from FAF or CFP, and 321 had gradable lesion data from both FAF and CFP.
  
  
  METHODS
  Atrophic lesion areas were measured by FAF and CFP to assess lesion progression over time. Lesion size assessments and best-corrected visual acuity (BCVA) were conducted at screening/baseline (day 0) and at 3 follow-up visits: month 6, month 12, and month 18 (or early exit).
  
  
  METHODS
  The GA lesion progression rate in disease subgroups and mean change from baseline visual acuity.
  
  
  RESULTS
  Mean (standard error) lesion size changes from baseline, determined by FAF and CFP, respectively, were 0.88 (0.1) and 0.78 (0.1) mm(2) at 6 months, 1.85 (0.1) and 1.57 (0.1) mm(2) at 12 months, and 3.14 (0.4) and 3.17 (0.5) mm(2) at 18 months. The mean change in lesion size from baseline to month 12 was significantly greater in participants who had eyes with multifocal atrophic spots compared with those with unifocal spots (P < 0.001) and those with extrafoveal lesions compared with those with foveal lesions (P = 0.001). The mean (standard deviation) decrease in visual acuity was 6.2 ± 15.6 letters for patients with image data available. Atrophic lesions with a diffuse (mean 0.95 mm(2)) or banded (mean 1.01 mm(2)) FAF pattern grew more rapidly by month 6 compared with those with the "none" (mean, 0.13 mm(2)) and focal (mean, 0.36 mm(2)) FAF patterns.
  
  
  CONCLUSIONS
  Although differences were observed in mean lesion size measurements using FAF imaging compared with CFP, the measurements were highly correlated with one another. Significant differences were found in lesion progression rates in participants stratified by hyperfluorescence pattern subtype. This large GA natural history study provides a strong foundation for future clinical trials.
authors.affiliation: Department of Ophthalmology, University of Bonn, Bonn, Germany; GRADE Reading Center, University of Bonn, Bonn, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Schmitz-Valckenberg
authors.affiliation: Université Pierre et Marie Curie and Institut de la Vision, Paris, France.
authors.forename: José-Alain
authors.initials: JA
authors.lastname: Sahel
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin.
authors.forename: Ronald
authors.initials: R
authors.lastname: Danis
authors.affiliation: Department of Ophthalmology, University of Bonn, Bonn, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Fleckenstein
authors.affiliation: Department of Ophthalmology, Duke University, Durham, North Carolina.
authors.forename: Glenn J
authors.initials: GJ
authors.lastname: Jaffe
authors.affiliation: Department of Ophthalmology, University Hospital Bern, Inselspital, University Bern, Bern, Switzerland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wolf
authors.affiliation: Department of Ophthalmology, Kantonsspital Baselland, Liestal, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Pruente
authors.affiliation: Department of Ophthalmology, University of Bonn, Bonn, Germany; GRADE Reading Center, University of Bonn, Bonn, Germany. Electronic address: Frank.Holz@ukb.uni-bonn.de.
authors.forename: Frank G
authors.initials: FG
authors.lastname: Holz
mesh_terms: D000368:Aged; D018450:Disease Progression; D005260:Female; D005451:Fluorescein Angiography; D057092:Geographic Atrophy / Q000175:diagnosis*; D006801:Humans; D008268:Macular Degeneration / Q000150:complications; D008297:Male; D061848:Optical Imaging; D011446:Prospective Studies; D055213:Retinal Pigment Epithelium / Q000473:pathology*; D014792:Visual Acuity / Q000502:physiology