title: Cone structure imaged with adaptive optics scanning laser ophthalmoscopy in eyes with nonneovascular age-related macular degeneration.
abstract: OBJECTIVE
  To evaluate cone spacing using adaptive optics scanning laser ophthalmoscopy (AOSLO) in eyes with nonneovascular AMD, and to correlate progression of AOSLO-derived cone measures with standard measures of macular structure.
  
  
  METHODS
  Adaptive optics scanning laser ophthalmoscopy images were obtained over 12 to 21 months from seven patients with AMD including four eyes with geographic atrophy (GA) and four eyes with drusen. Adaptive optics scanning laser ophthalmoscopy images were overlaid with color, infrared, and autofluorescence fundus photographs and spectral domain optical coherence tomography (SD-OCT) images to allow direct correlation of cone parameters with macular structure. Cone spacing was measured for each visit in selected regions including areas over drusen (n = 29), at GA margins (n = 14), and regions without drusen or GA (n = 13) and compared with normal, age-similar values.
  
  
  RESULTS
  Adaptive optics scanning laser ophthalmoscopy imaging revealed continuous cone mosaics up to the GA edge and overlying drusen, although reduced cone reflectivity often resulted in hyporeflective AOSLO signals at these locations. Baseline cone spacing measures were normal in 13/13 unaffected regions, 26/28 drusen regions, and 12/14 GA margin regions. Although standard clinical measures showed progression of GA in all study eyes, cone spacing remained within normal ranges in most drusen regions and all GA margin regions.
  
  
  CONCLUSIONS
  Adaptive optics scanning laser ophthalmoscopy provides adequate resolution for quantitative measurement of cone spacing at the margin of GA and over drusen in eyes with AMD. Although cone spacing was often normal at baseline and remained normal over time, these regions showed focal areas of decreased cone reflectivity. These findings may provide insight into the pathophysiology of AMD progression. (ClinicalTrials.gov number, NCT00254605).
authors.affiliation: Department of Ophthalmology, University of California at San Francisco, San Francisco, California.
authors.forename: Shiri
authors.initials: S
authors.lastname: Zayit-Soudry
authors.forename: Jacque L
authors.initials: JL
authors.lastname: Duncan
authors.forename: Reema
authors.initials: R
authors.lastname: Syed
authors.forename: Moreno
authors.initials: M
authors.lastname: Menghini
authors.forename: Austin J
authors.initials: AJ
authors.lastname: Roorda
mesh_terms: D000368:Aged; D018450:Disease Progression; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D057092:Geographic Atrophy / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy; D017949:Retinal Cone Photoreceptor Cells / Q000473:pathology*; D015593:Retinal Drusen / Q000175:diagnosis*; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity
keywords: adaptive optics; age-related macular degeneration; cones; scanning laser ophthalmoscopy