title: Evaluation of optimized digital fundus reflex photographs for lens opacities in the age-related eye disease study 2: AREDS2 report 7.
abstract: OBJECTIVE
  We described the system for grading lens opacities using stereoscopic digital fundus reflex photographs in the Age-Related Eye Disease Study 2 (AREDS2) and compared reproducibility with the AREDS lens grading system, which used retroillumination film images.
  
  
  METHODS
  Stereoscopic fundus reflex photographs were acquired in a standardized fashion at baseline and annually. Images were enhanced and evaluated in the red channel at a central reading center. Percentage involvement of cortical and posterior subcapsular (PSC) lens opacities within the central 5 mm diameter zone of a modified AREDS lens grid was estimated. Reproducibility was assessed for contemporaneous variability (ongoing, monthly regrade on 5% of submissions, n = 777 eyes) and temporal drift (regrading a subset of baseline photographs annually, n = 88).
  
  
  RESULTS
  In the contemporaneous exercise, the agreement for presence of cortical opacities was 93% (κ = 0.86) and for PSC opacities it was 97% (κ = 0.83). Intraclass correlation (ICC) for area of central zone involvement was 0.95 for cortical and 0.99 for PSC opacities. Historic data for contemporaneous regrading of film-based images in AREDS showed an ICC of 0.94 for cortical and 0.82 for PSC. The final annual temporal drift exercise had a reproducibility of 95% for cortical and PSC opacities.
  
  
  CONCLUSIONS
  Digital grading using fundus reflex images with image enhancing tools has reproducibility comparable to film-based retroillumination images, and may be useful for centralized objective lens opacity assessment in clinical trials using widely available fundus cameras. Red reflex images limit evaluation to cortical and PSC opacities, and do not permit assessment of nuclear opacities. (ClinicalTrials.gov number, NCT00345176.).
authors.affiliation: Fundus Photograph Reading Center, Department of Ophthalmology and Visual Science, Madison, Wisconsin, USA.
authors.forename: Amitha
authors.initials: A
authors.lastname: Domalpally
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Danis
authors.forename: Emily Y
authors.initials: EY
authors.lastname: Chew
authors.forename: Traci E
authors.initials: TE
authors.lastname: Clemons
authors.forename: Susan
authors.initials: S
authors.lastname: Reed
authors.forename: John Paul
authors.initials: JP
authors.lastname: Sangiovanni
authors.forename: Frederick L
authors.initials: FL
authors.lastname: Ferris
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000150:complications / Q000473:pathology*; D018450:Disease Progression; D005654:Fundus Oculi; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007908:Lens, Crystalline / Q000473:pathology*; D008268:Macular Degeneration / Q000150:complications* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010781:Photography / Q000379:methods*; D015203:Reproducibility of Results
keywords: AREDS2; cataract; lens opacity