Pentacam sensitivity and specificity in detecting occludable angles

Purpose. 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.