[Comparison of simple methods to screen predisposing eye of primary angle-closure glaucoma]

6,584 population over 40 years old in Canton universities and factories were screened for the predisposing eyes of primary angle-closure glaucoma (PACG). In the screening, three methods for the measurement of anterior chamber depth were used and compared and the critical limits of two simple ones of them [peripheral anterior chamber depth (PACD) and oblique illumination test with a flashlight] were evaluated. It was found that the incidence of PACG is as high as 10.0% in eyes with axial anterior chamber depth (AACD) < or = 2.0 mm, it is 6.7% in eyes with peripheral anterior chamber depth (PACD) < or = 1/4 corneal thickness (CT) and is 6.9% in eyes with iris light band ratio (ILBR) < or = 1/4. Also, we found that the incidence of PACG is as high as 77.8% in eyes with AACD < or = 1.6 mm and 100.0% in, AACD < or = 1.4 mm. The authors propose that PACD < or = 1/4 CT and ILBR < or = 1/4 can be the critical values of the two methods for the primary step of PACG screening.