Primary chronic angle-closure glaucoma in Chinese--a clinical exploration of its pathogenesis and natural course

Forty-three cases (86 eyes) of primary chronic angle-closure glaucoma were randomly selected. An additional 44 cases (77 eyes) of primary acute angle-closure glaucoma and 30 normal subjects (34 eyes) were also randomly enrolled as control groups for comparison in the clinical study. Ultrasonic biometric measurements of the anterior chamber depth, lens thickness and axial length of the eyeball were performed. Using an potic microgauge attached to the slit-lamp, the entrance of anterior chamber angle was also calculated. The clinical manifestations and the natural course, including the characteristic appearance of anterior chamber angle, the form of peripheral anterior synechia as well as the facility of outflow, were carefully investigated. There were significant differences in the biometric parameters of the anterior segment of eye among above three groups. The facts reveal that the anatomic features of eyeball, especially in the anterior segment differentiate from those of primary acute angle-closure glaucoma. Follow-up study for the early stage cases showed that topical administration of miotics and/or peripheral iridectomy can effectively prevent iris from forming peripheral anterior synechia and thus halt its development. The criteria of diagnosis and the principles of prevention and treatment at the early stage cases were presented. The pathogenesis was discussed. We emphasized that the progressive stage after intermittent attacks of primary acute angle-closure glaucoma should not be confused with primary chronic angle-closure glaucoma.