title: Drusen Volume and Retinal Pigment Epithelium Abnormal Thinning Volume Predict 2-Year Progression of Age-Related Macular Degeneration.
abstract: OBJECTIVE
  To analyze the value of novel measures of retinal pigment epithelium-drusen complex (RPEDC) volume to predict 2-year disease progression of intermediate age-related macular degeneration (AMD).
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  Three hundred forty-five AMD and 122 non-AMD participants enrolled in the Age Related Eye Disease Study 2 Ancillary Spectral-Domain (SD) Optical Coherence Tomography (OCT) study.
  
  
  METHODS
  High-density SD OCT macular volumes were obtained at yearly study visits. The RPEDC abnormal thickening (henceforth, OCT drusen) and RPEDC abnormal thinning (RAT) volumes were generated by semiautomated segmentation of total RPEDC within a 5-mm-diameter macular field.
  
  
  METHODS
  Volume change and odds ratio (OR) with 95% confidence intervals (CI) for progression to advanced AMD with choroidal neovascularization (CNV) or central geographic atrophy (GA).
  
  
  RESULTS
  Complete volumes were obtained in 265 and 266 AMD eyes and in 115 and 97 control eyes at baseline and at year 2, respectively. In AMD eyes, mean (standard deviation) OCT drusen volume increased from 0.08 mm(3) (0.16 mm(3)) to 0.10 mm(3) (0.23 mm(3); P < 0.001), and RAT volume increased from 8.3 × 10(-4) mm(3) (20.8 × 10(-4) mm(3)) to 18.4 × 10(-4) mm(3) (46.6 × 10(-4) mm(3); P < 0.001). Greater baseline OCT drusen volume was associated with 2-year progression to CNV (P = 0.002). Odds of developing CNV increased by 31% for every 0.1-mm(3) increase in baseline OCT drusen volume (OR, 1.31; 95% CI, 1.06-1.63; P = 0.013). Greater baseline RAT volume was associated with significant 2-year increase in RAT volume (P < 0.001), noncentral GA (P < 0.001), and progression to central GA (P < 0.001). Odds of developing central GA increased by 32% for every 0.001-mm(3) increase in baseline RAT volume (OR, 1.32; 95% CI, 1.14-1.53; P < 0.001). In non-AMD eyes, all volumes were significantly lower than AMD eyes and showed no significant 2-year change.
  
  
  CONCLUSIONS
  Macular OCT drusen and RAT volumes increased significantly in AMD eyes over 2 years. These quantitative SD OCT biomarkers predict 2-year AMD progression and may serve as useful biomarkers for future clinical trials.
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Folgar
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Eric L
authors.initials: EL
authors.lastname: Yuan
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Monica B
authors.initials: MB
authors.lastname: Sevilla
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina; Department of Biomedical Engineering, Duke University, Durham, North Carolina.
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Chiu
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina; Department of Biomedical Engineering, Duke University, Durham, North Carolina.
authors.forename: Sina
authors.initials: S
authors.lastname: Farsiu
authors.affiliation: National Eye Institute, National Institutes of Health, Bethesda, Maryland.
authors.forename: Emily Y
authors.initials: EY
authors.lastname: Chew
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina; Department of Biomedical Engineering, Duke University, Durham, North Carolina. Electronic address: cynthia.toth@dm.duke.edu.
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Toth
mesh_terms: D000368:Aged; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008268:Macular Degeneration / Q000150:complications / Q000175:diagnosis*; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D015593:Retinal Drusen / Q000175:diagnosis* / Q000209:etiology; D055213:Retinal Pigment Epithelium / Q000473:pathology*; D013997:Time Factors; D041623:Tomography, Optical Coherence