title: Pentacam sensitivity and specificity in detecting occludable angles.
abstract: OBJECTIVE
  To assess the sensitivity and specificity of Pentacam measurements in detection of occludable angles and to provide cutoff values.
  
  
  METHODS
  Observational, single-center, cross-sectional study on 64 Caucasian eyes: 28 (43.7%) primary narrow angles or primary angle-closure glaucoma, and 36 (56.2%) controls: all subjects were evaluated and classified by gonioscopy (Shaffer classification). The following measurements have been considered: superior and inferior anterior chamber angle (ACA), temporal and nasal ACA, anterior chamber depth (ACD) using 5 value representation (central, superior, inferior, nasal, temporal), and anterior chamber volume (ACV). Validity of Pentacam parameters to detect patients in Shaffer 0 or I class was assessed by receiver operating characteristic (ROC) curves analysis; cutoffs were chosen as to maximize sensitivity and specificity.
  
  
  RESULTS
  All the considered Pentacam measures were statistically different between the 2 groups (p<0.0001). All Shaffer grade groups differed in all parameters (p<0.001), except for grade 0 and I, which did not differ in any. Area under the curve ROC analysis revealed high discriminant power of all Pentacam measures: ACA = 0.94; ACD = 0.91; ACD central = 0.89; and ACV = 0.89. Chosen cutoff values (ACA = 22.4°; ACD = 1.12 mm; ACD central = 1.93 mm; ACV = 84 mm3) allowed correct classification of narrow angles.
  
  
  CONCLUSIONS
  The study pointed out a high power of Pentacam AVA, ACV, and ACD in detecting occludable angles. Pentacam is simple to use, reliable, and noncontact, provides parameters in a short period, and represents a possible screening tool.
authors.affiliation: University Eye Clinic of Pavia, IRCCS Policlinico San Matteo Foundation, Pavia, Italy. gemma.rossi.md@gmail.com
authors.forename: Gemma C M
authors.initials: GC
authors.lastname: Rossi
authors.forename: Luigia
authors.initials: L
authors.lastname: Scudeller
authors.forename: Alessio
authors.initials: A
authors.lastname: Delfino
authors.forename: Marta
authors.initials: M
authors.lastname: Raimondi
authors.forename: Sara
authors.initials: S
authors.lastname: Pezzotta
authors.forename: Martina
authors.initials: M
authors.lastname: Maccarone
authors.forename: Elena
authors.initials: E
authors.lastname: Antoniazzi
authors.forename: Gian Maria
authors.initials: GM
authors.lastname: Pasinetti
authors.forename: Paolo Emilio
authors.initials: PE
authors.lastname: Bianchi
mesh_terms: D000368:Aged; D000867:Anterior Chamber / Q000473:pathology*; D003430:Cross-Sectional Studies; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis*; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D010781:Photography / Q000295:instrumentation*; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity