Abstract
Abstract: :
Purpose: To investigate the sensitivity and specificity of a newly developed non–contact scanning peripheral anterior chamber depth analyzer (SPAC) for diagnosing eyes with possible angle closure glaucoma (ACG). Methods: 1099 consecutive eyes from 561 patients with glaucoma at the University of Yamanashi Hospital were enrolled. SPAC scanned the anterior chamber depth from the optical axis to the limbus in approximately 0.5 second and took 21 consecutive slit–lamp images at 0.4 mm intervals. Of the enrolled eyes with glaucoma, 80 eyes with ACG attack, chronic ACG, or narrow eyes requiring laser iridotomy (LI) were categorized as possible ACG eyes that should be detected in a health examination, and other eyes with open angle were categorized as control eyes. Twenty eyes with ACG or narrow eyes requiring prophylactic LI were employed to determine threshold intervals from another patient group. The sensitivity and specificity of SPAC for diagnosing eyes with possible ACG were investigated. Results: Of the 1099 eyes examined, pertinent data could not be obtained for 64 eyes due to poor fixation, corneal opacity, and corneal deformity. The most useful conditions for distinguishing eyes with possible ACG from the control eyes by SPAC were as follows: any of two measured points should exceed 72% of the threshold interval, and the sensitivity and specificity should be 95.1% and 86.1%, respectively. Conclusions: To our knowledge, SPAC is the first system that enables diagnosis of eyes with possible ACG in a health examination. Therefore, it may be useful for preventing patients from acquired blindness due to ACG.
Keywords: clinical research methodology • imaging/image analysis: clinical • shape and contour