Prevalence and Determinants of Angle Closure in Central Sri Lanka: The Kandy Eye Study
Received 12 September 2008; received in revised form 4 March 2009; accepted 4 March 2009. published online 26 June 2009.
Purpose
To determine the prevalence and determinants of angle closure in the Kandy District of central Sri Lanka.
Design
Population-based, cross-sectional study.
Participants
Inhabitants aged 40 years or more from villages in the Kandy District were selected by randomized cluster sampling; 1721 eligible participants were identified, and 1375 participated in the study.
Methods
The examination included slit-lamp examination of the anterior segment, applanation tonometry, static and dynamic gonioscopy, dilated stereoscopic optic disc examination, and ultrasonic ocular biometry. Eyes that were primary angle-closure suspects (PACS) or had primary angle closure (PAC) or primary angle-closure glaucoma (PACG) were identified. Definitions were based on recommendations from the International Society for Geographic and Epidemiological Ophthalmology (ISGEO). Univariate and multivariate logistic regression analyses were performed with angle closure as the outcome variable.
Main Outcome Measures
Subjects with PACG, PACS, or PAC were pooled into a group considered to have angle closure.
Results
The prevalence of PACS, PAC, and PACG in at least 1 eye was 2.35% (95% confidence interval [CI], 0.0–4.7; 32 subjects), 1.86% (95% CI, 0.6–3.1, 25 participants), and 0.57% (95% CI, 0.0–1.2; 7 participants), respectively. The overall prevalence of angle closure was 4.7% (95% CI, 1.1–9.3; 64 participants). The mean axial length in those with angle closure (21.99 mm) was significantly shorter (P<0.001) than in those with open angles (22.47 mm), as was the mean anterior chamber depth (ACD) (2.47 mm compared with 2.81 mm), but the mean lens thickness in those with angle closure (4.51 mm) did not significantly differ (P = 0.44) from those with open angles (4.45 mm). Neither age nor nuclear opalescence was a significant predictor of angle closure in the multivariate model (P = 0.09 and 0.61, respectively); however, female gender was associated with a 9.2 times (P<0.001) increased risk of angle closure, and each millimeter decrease in ACD was associated with a 2.6 times increased risk of angle closure (P<0.001).
Conclusions
The overall prevalence of angle closure was 4.7%. Female gender and shallow ACD were significant independent predictors of angle closure in this Sri Lankan population.
Financial Disclosure(s)
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Available online: June 24, 2009.
1South Australian Institute of Ophthalmology and Department of Ophthalmology and Visual Sciences, Adelaide University, Adelaide, South Australia, Australia
Correspondence: Robert J. Casson, DPhil, FRANZCO, Associate Professor, South Australian Institute of Ophthalmology, Department of Ophthalmology and Visual Sciences, Adelaide University, South Australia, Australia 5000
Manuscript no. 2008-1093.
Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Pfizer Australia provided an unrestricted grant for this research.
ABSTRACT