title: Comparison of scanning laser polarimetry using variable corneal compensation and retinal nerve fiber layer photography for detection of glaucoma.
abstract: OBJECTIVE
  To compare retinal nerve fiber layer (RNFL) measurements obtained with scanning laser polarimetry (SLP) using variable corneal polarization compensation with standard red-free photography for detection of RNFL damage in glaucoma.
  
  
  METHODS
  This observational, cross-sectional study included 1 eye of each of 42 patients with open-angle glaucoma, 32 patients suspected of having glaucoma, and 40 healthy subjects. The RNFL measurements using SLP with variable corneal compensation were obtained within 3 months of red-free photographs. Two independent observers graded RNFL photographs using a standardized protocol. Superior and inferior hemiretinas were scored separately, and a global score was obtained by averaging scores from each hemiretina.
  
  
  METHODS
  The RNFL photography scores were compared with RNFL thickness measurements obtained with SLP. The receiver operating characteristic (ROC) curves were constructed to assess the abilities of the different methods to differentiate glaucoma patients from healthy subjects.
  
  
  RESULTS
  The RNFL thickness decreased with increased RNFL damage as assessed by photographs in both hemiretinas (R(2) = 15%-47%). The area under the ROC curve for the best SLP parameter, Nerve Fiber Indicator, was significantly greater than the area under the ROC curve for the global RNFL photography score (0.91 vs 0.84, P =.03).
  
  
  CONCLUSIONS
  A moderate correlation was found between RNFL thickness measurements obtained with SLP and RNFL scores from red-free photographs. Compared with semiquantitative RNFL photography scores, the best SLP parameter had a higher diagnostic accuracy to separate glaucoma patients from healthy subjects.
authors.affiliation: Hamilton Glaucoma Center and Department of Ophthalmology, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0946, USA.
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Medeiros
authors.forename: Linda M
authors.initials: LM
authors.lastname: Zangwill
authors.forename: Christopher
authors.initials: C
authors.lastname: Bowd
authors.forename: Kourosh
authors.initials: K
authors.lastname: Mohammadi
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D007834:Lasers; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009798:Ocular Hypertension / Q000175:diagnosis; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D010781:Photography / Q000379:methods*; D012372:ROC Curve; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D014792:Visual Acuity