Case Finding of Angle Closure Glaucoma in Public Health Examination With Scanning Peripheral Anterior Chamber Depth Analyzer

Abstract

Despite the fact that the occurrence of angle closure glaucoma (ACG) or acute primary angle closure (PAC) can be prevented, in many cases, nonphysicians fail to detect them in regular health examinations before their onset. This study was aimed at examining the utility of a newly developed noncontact scanning peripheral anterior chamber depth analyzer (SPAC) in finding eyes at risk of ACG and acute PAC in a public health examination by nonphysicians. A total of 535 local residents 40 years old or over were enrolled. In primary screening, nonphysicians use SPAC to determine up to 21 consecutive circumferential measurements of anterior chamber depth (ACD). The subjects were classified into 4 groups on basis of the previously established criteria: group 1: all ACD values above the minimum value of 72% confidence interval (CI); group 2: 1 or more ACD values below the minimum value of 72% or less than 4 ACD values below the minimum value of 95% CI; group 3: 4 or more ACD values below the minimum value of 95% CI; and group 4: no ACD data available. All the subjects from group 3 and those from group 2 or group 4 who were suspected to be at risk of ACG as diagnosed by a glaucoma specialist were subjected to a definitive examination. Fifty-seven (10.7%) subjects were recruited to the definitive examination. The final diagnoses were 1 subject with primary ACG (1.8%), 23 subjects with PAC (40.4%), 15 PAC suspect subjects (26.3%), and 18 subjects (31.6%) had eyes with open angle. All of them were from group 3. SPAC detected eyes at risk of ACG in a public health examination.