Angle Assessment by EyeCam, Goniophotography, and Gonioscopy

Purpose: To compare EyeCam (Clarity Medical Systems, Pleasanton, CA) and goniophotography in detecting angle closure, using gonioscopy as the reference standard. Methods: In this hospital-based, prospective, cross-sectional study, participants underwent gonioscopy by a single observer, and EyeCam imaging and goniophotography by different operators. The anterior chamber angle in a quadrant was classified as closed if the posterior trabecular meshwork could not be seen. A masked observer categorized the eyes as per the number of closed quadrants, and an eye was classified as having angle closure if there were 2 or more quadrants of closure. Agreement between the methods was analyzed by kappa statistic and comparison of area under receiver operating characteristic curves (AUC). Results: Eighty-five participants (85 eyes) were included, the majority of whom were Chinese. Angle closure was detected in 38 eyes (45%) with gonioscopy, 40 eyes (47%) using EyeCam, and 40 eyes (47%) with goniophotography (P = 0.69 in both comparisons, McNemar test). The agreement for angle closure diagnosis (by eye) between gonioscopy and the 2 imaging modalities was high (kappa = 0.86; 95% Confidence Interval (CI), 0.75-0.97), whereas the agreement between EyeCam and goniophotography was not as good (kappa = 0.72; 95% CI, 0.57-0.87); largely due to lack of agreement in the nasal and temporal quadrants (kappa = 0.55 to 0.67). The AUC for detecting eyes with gonioscopic angle closure was similar for goniophotography and EyeCam (AUC 0.93, sensitivity = 94.7%, specificity = 91.5%; P > 0.95). Conclusions: EyeCam and goniophotography have similarly high sensitivity and specificity for the detection of gonioscopic angle closure.