title: Multimodal assessment of microscopic morphology and retinal function in patients with geographic atrophy.
abstract: OBJECTIVE
  To correlate retinal function and visual sensitivity with retinal morphology revealed by ultrahigh-resolution imaging with adaptive optics-optical coherence tomography (AO-OCT), on patients with geographic atrophy.
  
  
  METHODS
  Five eyes from five subjects were tested (four with geographic atrophy [66.3 ± 6.4 years, mean ± 1 SD] and one normal [61 years]). Photopic and scotopic multifocal electroretinograms (mfERGs) were recorded. Visual fields were assessed with microperimetry (mP) combined with a scanning laser ophthalmoscope for high-resolution confocal retinal fundus imaging. The eye tracker of the microperimeter identified the preferred retinal locus that was then used as a reference for precise targeting of areas for advanced retinal imaging. Images were obtained with purpose-built, in-house, ultrahigh resolution AO-OCT. Fundus autofluorescence (FAF) and color fundus (CF) photographs were also acquired.
  
  
  RESULTS
  The AO-OCT imaging provided detailed cross-sectional structural representation of the retina. Up to 12 retinal layers were identified in the normal subject while many severe retinal abnormalities (i.e., calcified drusen, drusenoid pigment epithelium detachment, outer retinal tubulation) were identified in the retinae of the GA patients. The functional tests showed preservation of sensitivities, although somewhat compromised, at the border of the GA.
  
  
  CONCLUSIONS
  The images provided here advance our knowledge of the morphology of retinal layers in GA patients. While there was a strong correlation between altered retinal structure and reduction in visual function, there were a number of examples in which the photoreceptor inner/outer segment (IS/OS) junctions lost reflectivity at the margins of GA, while visual function was still demonstrated. This was shown to be due to changes in photoreceptor orientation near the GA border.
authors.affiliation: Department of Ophthalmology and Vision Science, University of California, Davis, Davis, California 95817, USA. apanorgias@ucdavis.edu
authors.forename: Athanasios
authors.initials: A
authors.lastname: Panorgias
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Zawadzki
authors.forename: Arlie G
authors.initials: AG
authors.lastname: Capps
authors.forename: Allan A
authors.initials: AA
authors.lastname: Hunter
authors.forename: Lawrence S
authors.initials: LS
authors.lastname: Morse
authors.forename: John S
authors.initials: JS
authors.lastname: Werner
mesh_terms: D000368:Aged; D055253:Color Vision / Q000502:physiology; D003623:Dark Adaptation / Q000502:physiology; D004596:Electroretinography / Q000379:methods; D005260:Female; D057092:Geographic Atrophy / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D008875:Middle Aged; D061848:Optical Imaging / Q000379:methods; D012160:Retina / Q000473:pathology / Q000502:physiology; D041623:Tomography, Optical Coherence / Q000379:methods*; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields / Q000502:physiology
keywords: adaptive-optics OCT; geographic atrophy; microperimetry; multifocal ERG; scotopic mfERG