Primary angle closure disease tied to older age, elevated IOP, shallow anterior chamber

Primary angle-closure disease (PACD) in Singapore has a 6-year incidence rate of 3.5 percent, with risk factors including older age, higher intraocular pressure (IOP) levels, and shallower anterior chamber, a study has found. On the other hand, late posterior subcapsular cataract appears to be protective.

The study used data from the Singapore Epidemiology of Eye Diseases. Out of 6,762 participants aged ≥40 years who attended the follow up examination, 5,298 individuals at risk of primary angle-closure glaucoma (PACG) and 5,060 of those at risk of PACD were included in the analyses. PACD included primary angle closure suspect (PACS), primary angle closure (PAC), and PACG.

Baseline evaluation was conducted between 2004 and 2010, and the 6-year follow up visit between 2011 and 2017. Researchers performed standardized examinations including slit lamp biomicroscopy, indentation gonioscopy, IOP measurement, and static automated perimetry.

The 6-year age-adjusted PACD incidence was 3.50 percent (95 percent confidence interval [CI] 2.94–4.16). Multivariable logistic regression analysis revealed that the odds of PACD grew with increasing age per decade (odds ratio [OR], 1.35, 95 percent CI, 1.15–1.59), higher IOP (OR, 1.04, 95 percent CI, 1.00–1.08), and shallower anterior chamber depth (OR, 1.11, 95 percent CI, 1.08–1.14) at baseline.

On the other hand, late posterior subcapsular cataract was associated with lower odds of PACD (OR, 0.60, 95 percent CI, 0.48–0.76).

The 6-year age-adjusted incidences of PACG, PAC, and PACS were 0.29 percent (95 percent CI, 0.14– 0.55), 0.46 percent (95 percent CI, 0.29–0.75), and 2.54 percent (95 percent CI, 2.07–3.12), respectively.