Use of EyeCam for imaging the anterior chamber angle

Abstract

Purpose: To compare EyeCam (Clarity Medical Systems, Pleasanton, CA) imaging with gonioscopy for detecting angle closure.

Methods: In this prospective, hospital-based study, subjects underwent gonioscopy by a single observer and EyeCam imaging by a different operator. EyeCam images were graded by two masked observers. The anterior chamber angle in a quadrant was classified as closed if the trabecular meshwork could not be seen. The eye was classified as having angle closure if two or more quadrants were closed.

Results: One hundred fifty-two subjects were studied. The mean age was 57.4 years (SD 12.9) and there were 82 (54%) men. Of the 152 eyes, 21 (13.8%) had angle closure. The EyeCam provided clear images of the angles in 98.8% of subjects. The agreement between the EyeCam and gonioscopy for detecting angle closure in the superior, inferior, nasal, and temporal quadrants based on agreement coefficient (AC1) statistics was 0.73, 0.75, 0.76, and 0.72, respectively. EyeCam detected more closed angles than did gonioscopy in all quadrants (P < 0.05). With gonioscopy, 21/152 (13.8%) eyes were diagnosed as angle closure compared to 41 (27.0%) of 152 with EyeCam (P < 0.001, McNemar Test), giving an overall sensitivity of 76.2% (95% confidence interval [CI], 54.9%-90.7%), specificity of 80.9% (95%CI, 73.5%-87.3%), and an area under the receiver operating characteristic curve (AUC) of 0.79.

Conclusions: The EyeCam showed good agreement with gonioscopy for detecting angle closure. However, it detected more closed angles than did gonioscopy in all quadrants.