Abstract
Purpose: :
There have been only limited glaucoma-related epidemiological surveys with optic disc photographs in the native Chinese population of Mainland China. We conducted a population-based survey in rural and urban regions of Greater Beijing to assess the prevalence of glaucoma in adult Chinese.
Methods: :
The Beijing Eye Study, a cross-sectional prevalence study, included 4439 subjects with an age of 40+ years residing in 3 rural villages and 4 urban communities. All subjects received refractometry, frequency-doubling perimetry(C 20-1), non-contact tonometry, slit lamp and fundus photography (centered at optic disc and macula). Glaucoma was defined by the appearance of the optic disc on fundus photographs with a notch in the neuroretinal rim in the temporal inferior and / or superior region, a localized retinal nerve layer defect which could not be explained by any other cause than glaucoma, and an abnormally large cup in relation to the size of the optic disc. Gonioscopy was performed for all patients with glaucoma and glaucoma suspects.
Results: :
Glaucoma was detected in 220 eyes (prevalence:2.5±0.2% (mean±standard error) (95% confidence interval (CI):2.2,2.8) of 135 subjects (3.1±0.3%; 95%CI:2.6,3.6). Glaucoma frequency increased with age (P<0.001). The prevalence of glaucoma for the age groups of 40-49 years, 50-59 years, 60-69 years, and 70+ years was 1.0%, 1.5%, 4.1%, and 11.3%, respectively. Glaucoma prevalence was not associated with gender (P=0.13), and rural region versus urban region (P=0.05). It increased significantly with increasing myopic refractive error (P<0.001). Out of the 135 glaucoma subjects with glaucomatous optic nerve damage, 96 (71%) were classified as open-angle glaucoma, and 39 (29%) as angle-closure glaucoma. Using the data of the census of Beijing in 2001 to correct for population demographic considerations, the standardized prevalences of primary open-angle glaucoma and primary angle-closure glaucoma were 2.05% and 0.92%, respectively.
Conclusions: :
The glaucoma prevalence as defined by the appearance of the optic nerve head was 3.1% and increased with age. The prevalence is comparable with figures from Caucasian populations. In agreement with recent studies on East Asian populations, angle-closure glaucoma is less common than open-angle glaucoma in the adult Chinese population.
Keywords: optic disc • intraocular pressure