title: In vivo imaging of photoreceptor disruption associated with age-related macular degeneration: A pilot study.
abstract: OBJECTIVE
  Age-related macular degeneration is one of the leading causes of vision loss in the developed world. As the disease progresses, the central part of the retina, called the macula, is compromised leading to a disruption of both structure and visual function. In this study, we investigate the disruption of macular photoreceptor cells in vivo as a function of disease stage in patients with the dry form of age-related macular degeneration AMD.
  
  
  METHODS
  An investigational confocal Adaptive Optics Scanning Laser Ophthalmoscope (AO-SLO) was used to obtain high resolution images of the macular photoreceptor mosaic in patients previously diagnosed with AMD. Four patients were selected as representative cases, comprising each of the four clinical stages of AMD progression.
  
  
  RESULTS
  AO-SLO imaging revealed slight disruption in the photoreceptor mosaic in early stage AMD due to focal drusen formation and identified several small drusen deposits that were not observed with standard clinical imaging techniques. An increase in photoreceptor disruption was visualized within the macula in direct correlation with the stage of AMD progression leading to a decrease in visual acuity. Large coalescent drusen and areas of geographic atrophy in advanced stage dry AMD exhibited a significant decrease in visible photoreceptor density. Significant decrease in photoreceptor counts (∼35-50%) were observed when comparing earlier stages of AMD progression (Categories I and II) to later stages of the disease (Categories III and IV).
  
  
  CONCLUSIONS
  This study demonstrates the capabilities of adaptive optics retinal imaging to monitor disruption of individual photoreceptor cells as a function of disease progression yielding valuable diagnostic findings in early stage AMD beyond what can be learned about the health of photoreceptors using conventional retinal imaging techniques. Lasers Surg. Med. 44: 603-610, 2012. © 2012 Wiley Periodicals, Inc.
authors.affiliation: Center for Biomedical Engineering, University of Texas Medical Branch, Galveston, Texas 77555; Human Pathophysiology and Translational Medicine, University of Texas Medical Branch, Galveston, Texas 77555.
authors.forename: Adam
authors.initials: A
authors.lastname: Boretsky
authors.forename: Faraz
authors.initials: F
authors.lastname: Khan
authors.forename: Garrett
authors.initials: G
authors.lastname: Burnett
authors.forename: Daniel X
authors.initials: DX
authors.lastname: Hammer
authors.forename: R Daniel
authors.initials: RD
authors.lastname: Ferguson
authors.forename: Frederik
authors.initials: F
authors.lastname: van Kuijk
authors.forename: Massoud
authors.initials: M
authors.lastname: Motamedi
mesh_terms: D000704:Analysis of Variance; D002452:Cell Count; D018450:Disease Progression; D057092:Geographic Atrophy / Q000473:pathology; D006801:Humans; D007834:Lasers; D008268:Macular Degeneration / Q000145:classification / Q000473:pathology*; D009887:Ophthalmoscopy; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology*; D010865:Pilot Projects; D015593:Retinal Drusen / Q000473:pathology; D041623:Tomography, Optical Coherence; D014792:Visual Acuity