Potential of the Pentacam in Screening for Narrow Angles in Patients with Chronic Angle-Closure Glaucoma

Abstract

Background: Chronic angle-closure glaucoma (CACG) is a visually destructive disease. Effective management of CACG requires identifying eyes with narrow angle.

Objective: To compare pentacam with gonioscopy in detecting narrow angles in eyes with CACG.

Method: We enrolled 101 eyes with glaucoma. Gonioscopy was performed on all eyes. Using Shaffer’s grading, subjects were classified into angle closure and open angle. Anterior chamber volume (ACV) and anterior chamber depth (ACD) were measured with the pentacam. Receiver operating curve was constructed for each parameter and the area under the curve (AUC) was calculated.

Results: Ten eyes (9.9%) were classified as angle closure on gonioscopy. To detect narrow angles, ACV (AUC 0.956; 95% confidence interval (CI) 0.894–0.987) performed similar to ACD (AUC=0.930, p=0.33). Using a cutoff of 102 mm³ , ACV had 100% sensitivity and 88.5% specificity for detecting narrow angles in CACG patients. With an ACV cutoff of 102 mm³ , the PPV for detecting angle closure was 48.9% (95% CI, 34.8–68.2), while the NPV was 100% (94.1– 100%), using 9.9% prevalence of angle closure from this study.

Conclusion: ACV and ACD measured by the pentacam have the potential to determine narrow angles in eyes with CACG.

Keywords: Chronic angle-closure glaucoma, Pentacam HR, Anterior chamber volume, Gonioscopy