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

Publication
In Association for Research in Vision and Ophthalmology 2018 Annual Meeting

Purpose

Primary angle closure glaucoma (PACG) is a leading cause of ocular morbidity and blindness worldwide. PACG is the most severe stage of primary angle closure disease (PACD), which also includes primary angle closure suspect (PACS) and primary angle closure (PAC). The majority of PACG occurs in Asian countries where its prevalence is well studied. However, data on the prevalence of PACG in the United States is limited, especially among Asian Americans. This study examines the prevalence of PACD in adult Chinese American eyes based on population-derived data from the Chinese American Eye Study (CHES).

Methods

5492 Chinese Americans 50 years of age and older were recruited to CHES, a population-based study in Los Angeles, CA. 4426 received complete ophthalmologic exams, including visual acuity, intraocular pressure (IOP), slit-lamp examination, gonioscopy, and stereoscopic photography. PACS was defined as posterior trabecular meshwork that was not visible for 270 degrees or more on gonioscopy. PAC was defined as peripheral anterior synechiae (PAS) and/or IOP ≥ 21 mmHg without glaucomatous neuropathy (GON) in an eye with PACS. PACG was defined as evidence of GON in an eye with PACS. Suspected PACG (SPACG) was defined as GON in an eye that did not fit the definition of PACS but demonstrated previous laser peripheral iridotomy (LPI) or cataract surgery with presence of PAS.

Results

The prevalence of PACS, PAC, and PACG were 7.9% (95% CI: 7.1-8.8%), 3.1% (95% CI: 2.6-3.8%) and 0.4% (95% CI: 0.3-0.7%), respectively, in subjects without prior LPI or intraocular surgery. Prevalence of PACG was 0.6% when subjects with PACG and prior LPI (n = 11) or cataract surgery (n = 1) were included. Prevalence of PACG was 1.1% when the definition of angle closure was broadened to include SPACG (LPI, n = 11; cataract surgery, n = 9). Females had higher rates of PACS and PAC compared to PACG (p < 0.05). Age and intraocular pressure were greater in PACG compared to PACS and PAC subjects (p < 0.05). Refractive error, axial length, lens thickness, anterior chamber depth, and central corneal thickness were equal among all three groups (p > 0.05).

Conclusions

The prevalence of PACG is lower among Chinese Americans than East Asians based on standard definitions of angle closure. However, prevalences of PACS and PAC approximate rates seen in Asia.