title: Polarization-Sensitive Optical Coherence Tomography and Conventional Retinal Imaging Strategies in Assessing Foveal Integrity in Geographic Atrophy.
abstract: OBJECTIVE
  To compare current imaging methods with respect to their ability to detect the condition of the fovea in patients with geographic atrophy (GA).
  
  
  METHODS
  The retinas of 176 eyes with GA were imaged using two spectral-domain optical coherence tomography (SD-OCT) systems, Cirrus HD-OCT and Spectralis HRA+OCT, and fundus autofluorescence (FAF) and infrared imaging (IR) was used in the scanning laser ophthalmoscope (SLO) mode. Polarization-sensitive OCT (PS-OCT), which selectively visualizes the RPE in addition to SD-OCT features, was used to image 95 eyes. Geographic atrophy lesions were categorized as fovea spared, involved, or not quantifiable (grades 0, 1, and 2). Morphologic gradings were subsequently correlated with best-corrected visual acuity (BCVA) measurements to independently identify the corresponding functional condition of the fovea. Cohen's κ statistics with a bootstrap method was applied to compare retinal imaging methods.
  
  
  RESULTS
  In PS-OCT, 84% of eyes with BCVA greater than or equal to 20/40 were detected, whereas in conventional retinal imaging the rate ranged from 27% in FAF to 45% in the SD-OCT segment. Cohen's κ statistics revealed significant differences between the gradings of PS-OCT and conventional imaging with κ = 0.488 and a global Hotelling's T2 statistic of 17.9 with a P value of P = 0.003. Statistical tests revealed no statistically significant differences between the conventional retinal imaging modalities.
  
  
  CONCLUSIONS
  Polarization-sensitive OCT can better allow correct grading of the fovea in relation to BCVA and identify foveal sparing than other imaging modalities. The differences in imaging precision should be considered in diagnostic and therapeutic evaluations.
authors.affiliation: Department of Ophthalmology Medical University of Vienna, Vienna, Austria.
authors.forename: Ramzi G
authors.initials: RG
authors.lastname: Sayegh
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Zotter
authors.affiliation: Department of Ophthalmology Medical University of Vienna, Vienna, Austria.
authors.forename: Philip K
authors.initials: PK
authors.lastname: Roberts
authors.affiliation: Chair of Bioinformatics Research Group, Department of Biotechnology, BOKU University Vienna, Austria.
authors.forename: Maciej M
authors.initials: MM
authors.lastname: Kandula
authors.affiliation: Department of Ophthalmology Medical University of Vienna, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Sacu
authors.affiliation: Chair of Bioinformatics Research Group, Department of Biotechnology, BOKU University Vienna, Austria.
authors.forename: David P
authors.initials: DP
authors.lastname: Kreil
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Baumann
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Pircher
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Christoph K
authors.initials: CK
authors.lastname: Hitzenberger
authors.affiliation: Department of Ophthalmology Medical University of Vienna, Vienna, Austria.
authors.forename: Ursula
authors.initials: U
authors.lastname: Schmidt-Erfurth
mesh_terms: D000368:Aged; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods*; D005584:Fovea Centralis / Q000473:pathology*; D005654:Fundus Oculi; D057092:Geographic Atrophy / Q000175:diagnosis*; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D055213:Retinal Pigment Epithelium / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity