title: Retinal pigment epithelium findings in patients with albinism using wide-field polarization-sensitive optical coherence tomography.
abstract: OBJECTIVE
  To investigate pigmentation characteristics of the retinal pigment epithelium (RPE) in patients with albinism using wide-field polarization-sensitive optical coherence tomography compared with intensity-based spectral domain optical coherence tomography and fundus autofluorescence imaging.
  
  
  METHODS
  Five patients (10 eyes) with previously genetically diagnosed albinism and 5 healthy control subjects (10 eyes) were imaged by a wide-field polarization-sensitive optical coherence tomography system (scan angle: 40 × 40° on the retina), sensitive to melanin contained in the RPE, based on the polarization state of backscattered light. Conventional intensity-based spectral domain optical coherence tomography and fundus autofluorescence examinations were performed. Retinal pigment epithelium-pigmentation was analyzed qualitatively and quantitatively based on depolarization assessed by polarization-sensitive optical coherence tomography.
  
  
  RESULTS
  This study revealed strong evidence of polarization-sensitive optical coherence tomography to specifically image melanin in the RPE. Depolarization of light backscattered by the RPE in patients with albinism was reduced compared with normal subjects. Heterogeneous RPE-specific depolarization characteristics were observed in patients with albinism. Reduction of depolarization observed in the light backscattered by the RPE in patients with albinism corresponds to expected decrease of RPE pigmentation. The degree of depigmentation of the RPE is possibly associated with visual acuity. Findings suggest that different albinism genotypes result in heterogeneous levels of RPE pigmentation.
  
  
  CONCLUSIONS
  Polarization-sensitive optical coherence tomography showed a heterogeneous appearance of RPE pigmentation in patients with albinism depending on different genotypes.
authors.affiliation: *Department of Ophthalmology, Medical University of Vienna, Vienna, Austria; and †Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Christopher
authors.initials: C
authors.lastname: Schütze
authors.forename: Markus
authors.initials: M
authors.lastname: Ritter
authors.forename: Robert
authors.initials: R
authors.lastname: Blum
authors.forename: Stefan
authors.initials: S
authors.lastname: Zotter
authors.forename: Bernhard
authors.initials: B
authors.lastname: Baumann
authors.forename: Michael
authors.initials: M
authors.lastname: Pircher
authors.forename: Christoph K
authors.initials: CK
authors.lastname: Hitzenberger
authors.forename: Ursula
authors.initials: U
authors.lastname: Schmidt-Erfurth
mesh_terms: D000328:Adult; D000417:Albinism / Q000473:pathology* / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008543:Melanins / Q000032:analysis; D008875:Middle Aged; D010641:Phenotype; D055213:Retinal Pigment Epithelium / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000295:instrumentation* / Q000379:methods; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D008543:Melanins