To determine the 6-year incidence of primary glaucoma and its risk factors in an Indian population in Singapore DESIGN: Cohort population-based study PARTICIPANTS: Indian adults aged between 40 and 80 years living in Singapore. A total of 3,400 subjects participated in the baseline examination between 2007 and 2009. Of them, 2,200 (response rate= 75.5 % of those eligible) participated in the 6-year follow-up visit between 2013 and 2015.
Standardized examination and investigations were performed, including indentation gonioscopy, intraocular pressure (IOP) measurement, optic disc examination and static automated perimetry. Glaucoma was defined according to the International Society Geographical and Epidemiological Ophthalmology criteria.
Incidence of primary open angle glaucoma and primary angle closure glaucoma RESULTS: The age-standardized incidences of primary glaucoma, primary open angle glaucoma (POAG) and angle closure glaucoma (PACG) were 1.68% (95% confidence interval [CI] 1.21, 2.32), 1.37% (95% CI, 0.94, 1.96) and 0.32% (95% CI, 0.15, 0.66) respectively. For eyes with ocular hypertension (n=45) at baseline, the incidence of POAG was 4.83 % (95% CI, 1.24, 17.21) and for eyes with primary angle closure (n=14)/primary angle closure suspect (n=101), the incidence of developing PACG was 1.82% (95% CI, 0.37, 9.68). Baseline factors significantly associated with risk of developing primary glaucoma include older age (per decade odds ratio [OR] = 1.84 ;95% CI, 1.44-2.36; P<0.001), larger vertical cup-disc ratio (per 0.1 unit; OR = 2.78; 95% CI, 2.12- 3.64; P<0.001) and higher IOP (per mmHg; OR=1.25; 95% CI, 1.13-1.38; P<0.001). However, 71 out of 85 eyes (84.5%) diagnosed with incident glaucoma had IOP of less than 21 mmHg at the time of examination.
Our study shows that the overall age-standardized incidence of primary glaucoma was 1.68% in an Indian population in Singapore. In our population, the incidence of POAG was only half and the incidence of PACG was similar to the incidence reported by the Chennai Eye Disease Study.
Copyright © 2020. Published by Elsevier Inc.