Prevalence and Risk Factors of Primary Angle Closure Disease in an Adult Chinese American Population: The Chinese American Eye Study.

OBJECTIVE

To assess the prevalence and risk factors of primary angle closure disease (PACD) among adult Chinese Americans.

DESIGN

Cross-sectional population-based study.

PARTICIPANTS

Total 4582 Chinese Americans 50 years and older from 15 census tracts in Monterey Park, CA.

METHODS

Participants received complete eye exams, including gonioscopy, fundus photography, and standard automated perimetry. Primary angle closure suspect (PACS) was defined as non-visible posterior trabecular meshwork for ≥270° on gonioscopy. Primary angle closure (PAC) was defined as PACS with peripheral anterior synechiae (PAS) and/or IOP≥21 mmHg without glaucomatous neuropathy (GON). PACG was defined as PACS or PAC with GON. Suspected PACG (sPACG) was defined as GON without PACS or PAC but with evidence of prior laser iridotomy or cataract surgery with residual PAS. Multivariable logistic regression models were developed to identify risk factors for PACS, PAC, and PACG.

MAIN OUTCOME MEASURES: Prevalence and risk factors of PACS, PAC, and PACG.

RESULTS

Data from 4,310 CHES participants were included in the analysis. The prevalence of PACS, PAC, and PACG were 8.1% (95% CI: 7.3%-9.0%; N = 351), 3.1% (95% CI: 2.6%-3.6%; N = 132), and 1.1% (95% CI: 0.8%-1.4%; N = 46), respectively. Prevalence of PACG and sPACG combined was 1.8% (95% CI: 1.4%-2.2%; N = 76). Older age (OR=1.06 per year), positive family history of glaucoma (OR=3.21), higher IOP (OR=1.17 per mmHg), and shorter axial length (OR=1.67 per mm) were significant risk factors (P < .003) for PACG on multivariable analysis. 75.0% of PACG cases were previously undiagnosed. There was one case of PACG with unilateral blindness and no cases with bilateral blindness.

CONCLUSION

PACG prevalence was not substantially lower among Chinese Americans compared to mainland Chinese. Older age, higher IOP, positive family history of glaucoma, and smaller AL conferred higher risk. While the majority of PACG cases were undetected, blindness was rare. Improved access to eye care and cataract surgery appears to mitigate severe visual morbidity associated with PACG.