title: Diagnostic capability of optical coherence tomography (Stratus OCT 3) in early glaucoma.
abstract: OBJECTIVE
  To evaluate the diagnostic capability of optical coherence tomography (Stratus OCT 3) for early glaucoma in Asian Indian eyes.
  
  
  METHODS
  Cross-sectional observational study.
  
  
  METHODS
  Two groups of patients (early glaucoma and normal) who satisfied the inclusion and exclusion criteria were included. Early glaucoma was diagnosed in presence of open angles, characteristic glaucomatous optic disc changes correlating with the visual field on automated perimetry (visual field defect fulfilling at least 2 of Anderson and Patella's 3 criteria with mean deviation > or = -6 dB). Normals had visual acuity > or =20/30, intraocular pressure <22 mmHg with normal optic disc and fields and no ocular abnormality.
  
  
  METHODS
  All patients underwent complete ophthalmic evaluation including visual field examination (24-2/30-2 SITA standard program) and imaging with Stratus OCT 3.
  
  
  METHODS
  Sensitivity, specificity, positive and negative predictive values, area under the receiving operating characteristic curve and likelihood ratios were calculated for various Stratus OCT 3 parameters.
  
  
  RESULTS
  Seventy-two eyes (72 patients) with early glaucoma and 96 eyes (96 normal subjects) were analyzed. The inferior maximum parameter had the best combination of sensitivity and specificity, 75% (95% confidence interval [CI], 70.2-79.8%) and 89.6% (95% CI, 82.6-96.6%), respectively. The 6-o'clock parameter had a sensitivity of 61.1% (95% CI, 52.3-69.9) and specificity of 99% (95% CI, 95-100); for an assumed prevalence of 5%, the positive and negative predictive values were 75% and 98%, respectively. The positive likelihood ratio for the 6-o'clock parameter (P<5%) in early glaucoma was 61.
  
  
  CONCLUSIONS
  Optical coherence tomography has moderate sensitivity with high specificity for the diagnosis of early glaucoma and may have a potential role in screening.
authors.affiliation: L. V. Prasad Eye Institute, Hyderabad, India. rajulparikh@lvpei.org
authors.forename: Rajul S
authors.initials: RS
authors.lastname: Parikh
authors.forename: Shefali
authors.initials: S
authors.lastname: Parikh
authors.forename: G Chandra
authors.initials: GC
authors.lastname: Sekhar
authors.forename: Rajesh S
authors.initials: RS
authors.lastname: Kumar
authors.forename: S
authors.initials: S
authors.lastname: Prabakaran
authors.forename: J Ganesh
authors.initials: JG
authors.lastname: Babu
authors.forename: Ravi
authors.initials: R
authors.lastname: Thomas
mesh_terms: D003430:Cross-Sectional Studies; D005188:False Negative Reactions; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity; D058609:Visual Field Tests; D014794:Visual Fields