Epidemiology of primary angle-closure glaucoma in a rural population in Shaanxi Province of China / 国际眼科杂志(Guoji Yanke Zazhi)

ABSTRACT

· AIM: To assess the prevalence and related risk factors for primary angle-closure glaucoma in a rural population for 40 years of age or older in Shaanxi Province.· METHODS: By using a stratified, cluster-based, random sampling technique, 8 500 persons of all ages were selected randomly, including 3 500 those aged 40 years or more, from the North, the South and the Middle of Shaanxi Province in Western China from July to December in 2003. All participants had an interview with a standard questionnaire and those questions related to glaucoma of previous diagnosis and treatment, family history and outbreak history. Then a detailed and relative eye examination was performed, including logarithm of the minimum angle of resolution visual acuity, external eye examination with slit-lamp biomicroscopy and fundus examination. The intraocular pressure was measured with Perkins applanation tonometry to those persons aged 50 years old or more and those with suspected increased IOP. A further examination was performed to those persons with suspicious glaucoma, including repeated tonometric examination, gonioscopy, dark room test, automated visual field testing, et al.·RESULTS: 6 815 of the eligible 8 500 persons of all ages were interviewed and examined from July to December in 2003, a response rate of 80.18%, including 2835 of the eligible 3 500 persons of 40 years old or more with a response rate of 81.00%. According to Van Herick method, the percentage of shallow peripheral anterior chamber was 13.6%, of which 10.4% was in grade 2, 3.0% in grade 1, and 0.2% in grade 0. In this rural population for 40 years of age or older 31 participants were found to have primary angle-closure glaucoma, with the prevalence of 1.09%. With multiple logistic analyses, the prevalence increased significantly with age (P=0.008), whereas no significant difference (Pgender=0.180, Peducation=0.199) was found in the rate with gender and education, although women and illiteracy seemed to be at increased risk of the disease (OR 1.77, 95%CI,0.77-4.10; OR 1.71, 95%CT, 0.76-3.87). Of 31 participants, 21 persons (67.74%) had not been previously diagnosed and treated. Of 10 participants previously diagnosed, 6 (60%) had been received peripheral iridectomy; nevertheless, no any other treatments were performed. 48.39% participants suffered from visual impairment in various degrees, of which the percentage of blindness in either eye accounted for 29.03%. Of those with primary angle-closure glaucoma, 22 persons (70.97%) were classified as having chronic from of the disease.· CONCLUSION: In this rural population in Shaanxi Province of China, the rate of occludable angles is 13.6%, more common than that reported previously in other Chinese populations. The prevalence of primary angle-closure glaucoma is close to that from other Asian populations, increasing with age. A majority of glaucoma was undiagnosed and untreated previously.