title: Value of polarisation-sensitive optical coherence tomography in diseases affecting the retinal pigment epithelium.
abstract: OBJECTIVE
  To evaluate pathological changes of retinal pigment epithelium (RPE) by polarisation-sensitive optical coherence tomography (PS-OCT).
  
  
  METHODS
  Forty-four eyes (22 patients) with significant pathologies of the RPE were evaluated using PS-OCT. A transversal scanning time domain OCT system was used for two-dimensional cross-sectional imaging of retinal polarisation properties.
  
  
  RESULTS
  The RPE scrambles the polarisation state of backscattered light (ie, acts as a depolarising layer), while the polarisation state of transmitted light is maintained. In patients with RPE pathologies irregularity, elevation, thickening or absence of the RPE is readily visualised by exploiting the depolarisation information. Polarisation scrambling in the sensory retina can be found in cases with advanced dry age-related macular degeneration. Sclera and fibrosis show characteristic birefringence in PS-OCT.
  
  
  CONCLUSIONS
  PS-OCT allows tissue identification based on polarisation scrambling and birefringence, providing additional information on RPE pathologies. It is a promising new tool for diagnosis, disease follow-up and evaluation of new treatment strategies.
authors.affiliation: Department of Ophthalmology, University Hospital Zurich, Frauenklinikstrasse 24, 8091 Zürich, Switzerland. stephan.michels@usz.ch
authors.forename: S
authors.initials: S
authors.lastname: Michels
authors.forename: M
authors.initials: M
authors.lastname: Pircher
authors.forename: W
authors.initials: W
authors.lastname: Geitzenauer
authors.forename: C
authors.initials: C
authors.lastname: Simader
authors.forename: E
authors.initials: E
authors.lastname: Götzinger
authors.forename: O
authors.initials: O
authors.lastname: Findl
authors.forename: U
authors.initials: U
authors.lastname: Schmidt-Erfurth
authors.forename: C K
authors.initials: CK
authors.lastname: Hitzenberger
mesh_terms: D001284:Atrophy / Q000175:diagnosis; D001718:Birefringence; D005355:Fibrosis / Q000175:diagnosis; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis; D010857:Pigment Epithelium of Eye / Q000473:pathology*; D012163:Retinal Detachment / Q000175:diagnosis; D012164:Retinal Diseases / Q000175:diagnosis*; D015593:Retinal Drusen / Q000175:diagnosis; D012167:Retinal Perforations / Q000175:diagnosis; D041623:Tomography, Optical Coherence / Q000379:methods*