Primary angle closure glaucoma in East Asia: educational attainment as a protective factor.

PURPOSE: To examine the relationship between education, other risk factors and incident primary angle closure glaucoma (PACG).

METHOD: Glaucoma was excluded in a group of 4597 Mongolian volunteers in 1999. After 6 years, 1892 traced participants had full ophthalmic examination, dilated disc photographs and agreed to complete a questionnaire on socio-economic status. PACG was diagnosed using both structural and functional evidence from objective grading of paired disc photographs, follow up visual fields and clinical examination. Ophthalmic examination included van Herick grading, Goldmann intraocular pressure (IOP), gonioscopy, lens opacity grading and dilated disc examination. Central anterior chamber depth, lens thickness and axial length were recorded using ultrasound A scan mounted on a slitlamp. Education level was assessed using national census categories.

RESULTS

PACG was diagnosed in 29 participants (6 year incidence = 1.53%, 95% confidence interval (CI) = 1.03-2.19%). In univariate analysis, risk factors for incident PACG included presence of refractive error, narrow van Herick grading of ≤15%, narrower average Shaffer grading, higher IOP, larger cup disc ratio and lower levels of education. In multivariate analysis, adjusted for age, sex, Shaffer grading, refractive error and IOP, those with no formal education were approximately 7 times more likely to develop PACG compared to those with >8 years of formal schooling (OR = 7.27, 95% CI = 2.73-19.38).

CONCLUSIONS

People with lower levels of education have a higher risk of incident PACG, independent of age, sex, IOP and axial length.