Elsevier

Ophthalmology

Volume 115, Issue 4, April 2008, Pages 655-660.e1
Ophthalmology

Original article
Prevalence of Primary Angle-Closure Disease in an Urban South Indian Population and Comparison with a Rural Population: The Chennai Glaucoma Study

Presented in part at: 21st Congress of the Asia Pacific Academy of Ophthalmology, June 2006, Singapore.
https://doi.org/10.1016/j.ophtha.2007.05.034Get rights and content

Objective

To determine the prevalence of primary angle-closure glaucoma (PACG), primary angle closure (PAC), and PAC suspect (PACS) in an urban population, and to compare prevalence and associated risk factors with a rural population.

Design

Population-based cross-sectional study.

Participants

Four thousand eight hundred subjects 40 years or older were selected from Chennai city using multistage random cluster sampling.

Intervention

All subjects had a complete ophthalmic examination that included logarithm of the minimum angle of resolution visual acuity, applanation tonometry, gonioscopy, grading of lens opacities, dilated fundus examination, optic disc photography, and visual fields.

Main Outcome Measures

Glaucoma was diagnosed using the International Society of Geographical and Epidemiological Ophthalmology classification.

Results

Three thousand eight hundred fifty (80.2%) responded; 34 subjects (17 female, 17 male) had PACG (0.88%; 95% confidence interval [CI], 0.60–1.16). The mean intraocular pressure (IOP) was 26.0±14.9 mmHg. Five subjects (14.7%) had been previously diagnosed to have glaucoma, 1 of whom had undergone glaucoma surgery and 2 of whom had been diagnosed to have open-angle glaucoma. Two subjects (5.9%) were bilaterally and 3 subjects (8.8%) were unilaterally blind. One hundred six subjects (2.75%; 95% CI, 2.01–3.49) were diagnosed to have PAC (62 female, 44 male). Thirty-nine subjects (36.8%) had presenting IOP > 24 mmHg, 83 (78.3%) had peripheral anterior synechiae, and 16 (15.1%) had both. Two hundred seventy-eight subjects (7.24%; 95% CI, 6.38–8.02) had PACS (183 female, 95 male). Prevalences of PACG and PACS were similar in the urban and rural populations. Primary angle closure prevalence was higher in the urban population (P<0.0001). Primary angle closure and PACG were positively associated with increasing age and IOP in both populations and were more common in rural women (odds ratio [OR], 4.3; 95% CI, 2.2–8.3). Association with hyperopia was seen only in the urban population (OR, 2.0; 95% CI, 1.4–2.8).

Conclusions

Prevalences of PACG and PACS were similar in the rural and urban populations; PAC was more common in the urban population. In both groups, the disease was asymptomatic. Poor detection rates were probably due to lack of gonioscopy as a routine part of an eye examination.

Section snippets

Materials and Methods

The CGS was carried out between June 2001 and May 2004. This study was approved by an institutional ethics review board and performed in accordance with the tenets of the Declaration of Helsinki for research involving human subjects. The CGS’s methods and design are described in detail elsewhere.11

In summary, a sample size of 4758 was arrived at assuming an 85% response rate, for an assumed 3% population prevalence of glaucoma, with a relative precision of 25% and a design effect of 2. Four

Results

Of the 4800 enumerated, 3850 subjects participated in the study (response rate, 80.2%). There were 1710 (44.4%) males and 2140 (55.6%) females. The mean age of the study population was 54.8±10.6 years (range, 40–103). Two thousand five hundred thirty-two subjects had normal and reliable suprathreshold VF test results in both eyes on frequency-doubling perimetry. The distribution of VCDR and IOP for the normal population was derived from the right eye measurements of these subjects. The mean

Discussion

Quigley and Broman estimate that, by 2010, 87% of angle-closure glaucoma (ACG) cases will be Asian.19 The currently reported prevalence rates are highest for Chinese, intermediate among Indians, and lowest for Japanese.19 There seems to be wide variation in the reported prevalence of PACG within India. The prevalence of PACG in southern India ranges from 0.5% to 4.3%,6, 7, 8, 9 whereas the reported prevalence of PACG in eastern India was only 0.23%.20

In this study, we report the prevalence

References (24)

  • A. Jacob et al.

    Prevalence of primary glaucoma in an urban south Indian population

    Indian J Ophthalmol

    (1998)
  • G.N. Rao

    Ophthalmology in India

    Arch Ophthalmol

    (2000)
  • Cited by (131)

    View all citing articles on Scopus

    Manuscript no. 2006-1286.

    Financial support: Chennai Willingdon Corporate Foundation, Chennai, India.

    View full text