title: Validity of screening for glaucomatous optic nerve damage using confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomograph II) in high-risk populations: a pilot study.
abstract: OBJECTIVE
  To evaluate whether confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomograph II [HRT II], Heidelberg Engineering, Heidelberg, Germany) is a valid tool for the detection of glaucomatous optic nerve damage.
  
  
  METHODS
  Observational, cross-sectional, nonconsecutive study in Montreal, Canada.
  
  
  METHODS
  Three hundred three nonconsecutive, high-risk persons were enrolled during a 6-month period.
  
  
  METHODS
  Participants underwent HRT II testing and a standard ophthalmologic examination, including gonioscopy, intraocular pressure measurement, and optic disc grading.
  
  
  METHODS
  Positive likelihood ratio (PLR) and negative likelihood ratio (NLR), sensitivities and specificities, positive predictive value (PPV) and negative predictive value (NPV), and kappa coefficients of agreement of Moorfields regression analysis (MRA), cup shape measure (CSM), height variation contour (HVC), and mean retinal nerve fiber layer thickness (MRNFL).
  
  
  RESULTS
  Three hundred three participants were enrolled, and 291 were examined clinically; 21 (7.2%) were found to have glaucoma. Heidelberg Retina Tomograph II testing was performed successfully and was of acceptable quality in 531 of 601 eyes (88%). When MRA was compared with the clinically based diagnosis, the weighted kappa coefficient was kappa = 0.567 (95% confidence interval [CI], 0.42-0.71) for the right eye and kappa = 0.516 (95% CI, 0.37-0.66) for the left eye. Best kappa coefficient of agreement was seen when normals were grouped with suspects in both clinical and MRA diagnosis (kappa = 0.604; 95% CI, 0.409-0.799 in the right eye). Depending on the gold standard and test-positive definitions for glaucoma, specificity ranged from 87% to 97%, sensitivity from 25% to 100%, PPV from 28% to 68%, NPV from 84% to 100%, PLR from 5.0 to 19.2, and NLR from 1.3 to 6.2. When CSM, HVC, and MRNFLT were compared with clinical diagnosis, all outcome measures were found to have lower ranges: specificity from 46.9% to 83.7%, sensitivity from 36.5% to 76.9%, PPV from 6% to 36%, NPV from 80% to 99%, PLR from 0.8 to 4.0, NLR from 0.9 to 3.0.
  
  
  CONCLUSIONS
  The results of this study suggest that a glaucoma screening program may be effective in detecting glaucoma when targeting high-risk populations. Heidelberg Retina Tomograph II testing may prove to be a useful tool in detecting glaucomatous optic nerve damage and could be used as part of a complete glaucoma screening protocol.
authors.affiliation: Centre de Recherche Guy-Bernier, Hopital Maisonneuve-Rosemont, Université de Montréal, Montreal, Canada. pavloh@hotmail.com
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Harasymowycz
authors.forename: Demosthenes G
authors.initials: DG
authors.lastname: Papamatheakis
authors.forename: Alvine Kamdeu
authors.initials: AK
authors.lastname: Fansi
authors.forename: Jacques
authors.initials: J
authors.lastname: Gresset
authors.forename: Mark R
authors.initials: MR
authors.lastname: Lesk
mesh_terms: D003430:Cross-Sectional Studies; D005189:False Positive Reactions; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D007834:Lasers; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy / Q000379:methods*; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014054:Tomography / Q000379:methods