Predictors for Incidence of Primary Open-Angle Glaucoma in a South Indian Population: The Chennai Eye Disease Incidence Study

doi:10.1016/j.ophtha.2014.01.014

Ophthalmology

Volume 121, Issue 7, July 2014, Pages 1370-1376

https://doi.org/10.1016/j.ophtha.2014.01.014 Get rights and content

Objective

To determine the 6-year incidence of primary open-angle glaucoma (POAG) and its associated predictors.

Design

Population-based cohort study.

Participants

A total of 4316 subjects without POAG at baseline who were 40 years of age and older from a south Indian population.

Methods

Participants were examined at baseline and after a 6-year interval. Detailed ophthalmic examination included applanation tonometry, gonioscopy, pachymetry, optic disc evaluation, and automated perimetry. Glaucoma was defined using the International Society of Geographical and Epidemiological Ophthalmology Classification. Multivariable logistic regression was performed to identify the baseline risk factors that could predict the incident POAG.

Main Outcome Measures

Six-year incidence of POAG and its associated risk factors.

Results

In 6 years, incident POAG developed in 129 subjects (2.9%; 95% confidence interval [CI], 2.4–3.4; male-to-female ratio, 65:64). Baseline age was a risk factor. In reference to the group 40 to 49 years of age, the incidence increased from 2.3 (95% CI, 1.4–3.7) for the group 50 to 59 years of age to 3.5 (95% CI, 2.2–5.7) for the group 60 to 69 years of age (P <0.001). Other baseline risk predictors were urban residence (odds ratio [OR], 1.6; 95% CI, 1.1–2.2; P = 0.01), higher intraocular pressure (IOP; OR, 2.0; 95% CI, 1.5–2.6 per 10 mmHg; P <0.001), myopia (OR, 1.7; 95%, CI, 1.1–2.5; P <0.001), and axial length (OR, 1.5; 95% CI, 1.0–2.2 per millimeter; P = 0.03). Thinner corneas with higher IOP at baseline had the highest incidence of POAG. In 80% of the urban population and 100% of the rural population, incident glaucoma was previously undetected.

Conclusions

A significant proportion of this population demonstrated incident POAG. The baseline risk factors could help in identifying those at highest risk of disease.

Section snippets

Study Population

The methodology of and the prevalence of POAG from the Chennai Glaucoma Study were reported previously.16, 17, 18 In summary, the Chennai Glaucoma Study was a cross-sectional population-based study conducted to measure the prevalence of glaucoma in a rural and urban population in southern India. The study cohort consisted of 9600 subjects (rural-to-urban ratio, 4800:4800) 40 years of age or older and was carried out from 2001 through 2004. From the cohort, 7774 subjects (rural-to-urban ratio,

Results

At the baseline prevalence study, 7774 subjects were examined. We could not contact 1752 subjects (rural-to-urban ratio, 877:875) who had migrated with no forwarding address. Of the 6022 subjects (rural-to-urban ratio, 3047:2975) who could be contacted, information indicated that 590 participants had died. The numbers of eligible subjects were 5432 and 4421 (rural-to-urban ratio, 2510:1911), and they were examined at the base hospital. The response rate for this study was 81.3%. The reasons for

Discussion

The Chennai Eye Disease Incidence Study is the first prospective, longitudinal study from India that reports the incidence of POAG from a large cohort of rural and urban dwellers from southern India. The 6-year crude incidence of POAG was 2.9% and age and gender adjusted incidence was 2.4%. The associated baseline risk factors that could predict incident POAG were older age, urban location, higher IOP, myopia (SEQ, <−0.50 D), and axial length. The risk of incident POAG with higher baseline IOP

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Cited by (35)

Six-Year Incidence and Risk Factors for Primary Open-Angle Glaucoma and Ocular Hypertension: The Singapore Epidemiology of Eye Diseases Study
2024, Ophthalmology Glaucoma
To determine the incidence and risk factors for primary open-angle glaucoma (POAG) and ocular hypertension (OHT) in a multiethnic Asian population.
Population-based cohort study.
The Singapore Epidemiology of Eye Diseases study included 10 033 participants in the baseline examination between 2004 and 2011. Of those, 6762 (response rate = 78.8%) participated in the 6-year follow-up visit between 2011 and 2017.
Standardized examination and investigations were performed, including slit lamp biomicroscopy, intraocular pressure (IOP) measurement, pachymetry, gonioscopy, optic disc examination and static automated perimetry. Glaucoma was defined according to a combination of clinical evaluation, ocular imaging (fundus photo, visual field, and OCT) and criteria given by International Society of Geographical and Epidemiological Ophthalmology. OHT was defined on the basis of elevated IOP over the upper limit of normal; i.e., 20.4 mmHg, 21.5 mmHg, and 22.6 mmHg for the Chinese, Indian, and Malay cohort respectively, without glaucomatous optic disc change.
Incidence of POAG, OHT, and OHT progression.
The overall 6-year age-adjusted incidences of POAG and OHT were 1.31% (95% confidence interval [CI], 1.04–1.62) and 0.47% (95% CI, 0.30–0.70). The rate of progression of baseline OHT to POAG at 6 years was 5.32%. Primary open-angle glaucoma incidence was similar (1.37%) in Chinese and Indians and lower (0.80%) in Malays. Malays had higher incidence (0.79%) of OHT than Indians (0.38%) and Chinese (0.37%). Baseline parameters associated with higher risk of POAG were older age (per decade: odds ratio [OR], 1.90; 95% CI, 1.54–2.35; P < 0.001), higher baseline IOP (per mmHg: OR, 1.20; 95% CI, 1.12–1.29; P < 0.001) and longer axial length (per mm: OR, 1.22; 95% CI, 1.07–1.40, P = 0.004).
Six-year incidence of POAG was 1.31% in a multiethnic Asian population. Older age, higher IOP, and longer axial length were associated with higher risk of POAG. These findings can help in future projections and guide public healthcare policy decisions for screening at-risk individuals.
The authors have no proprietary or commercial interest in any materials discussed in this article.
Degree of Myopia and Glaucoma Risk: A Dose-Response Meta-analysis
2022, American Journal of Ophthalmology
Citation Excerpt :
The 24 studies, with a total study population of 514,265 individuals, had been conducted in 11 countries: 4 studies in the United States, 29–32 4 in India, 33–36 3 in China, 37–39 2 in Japan, 40,41 2 in South Korea, 42,43 2 in Australia, 44,45 3 in Singapore (Malay, 46 Indian, 47 and Chinese 48), and 1 study each in Myanmar, 49 Sri Lanka, 50 Greece, 51 and Barbados. 52 In 13 of those studies, 33,34,36,37,39,43,45–50,52 myopia was defined based on an SE of −0.5 D, and 7 others 29–32,41,44,51 reported myopia of SE less than −1.0 D. The characteristics of all of the included studies are summarized in Table 1.
To verify the dose-response relation between the degree of myopia and open-angle glaucoma (OAG) risk
Dose-response meta-analysis.
We searched the PubMed, EMBASE, and Cochrane Library databases for population-based studies published until November 30, 2020, and reporting on both myopia and OAG. Random-effect models generated pooled odds ratios (OR) and 95% CIs. Results robustness was confirmed by influence and subgroup analyses. A 2-stage dose-response meta-analysis calculated the OAG risk per unit dose of myopia (spherical equivalent [SE] decrease of 1 diopter [D]) and examined the relationship pattern.
The meta-analysis comprised 24 studies in 11 countries (514,265 individuals). The pooled OR of any myopia degree's association with OAG was 1.88 (95% CI, 1.66-2.13; I² = 53%). The OR differences based on ethnicity (Asians vs Westerners) or 5 geographic areas were not statistically significant (P = .80 and P = .06, respectively). The pooled ORs of the associations between low, moderate, moderate-to-high, high myopia, and OAG were 1.50 (95% CI, 1.29-1.76), 1.69 (95% CI, 1.33-2.15), 2.27 (95% CI, 1.74-2.96), and 4.14 (95% CI, 2.57-6.69), respectively. According to the dose-response meta-analysis, the pooled OR (per SE 1-D change) was 1.21 (95% CI, 1.15-1.28). The OAG risk accelerated at approximately −6 D, and further accelerated from −8 D, showing a nonlinear concave upward slope (P = .03).
For each unit (1-D) increase in myopia, the risk of glaucoma increases by approximately 20%. The risk more steeply increases in high-degree myopia, representing a significant nonlinear relationship.
Six-Year Incidence and Risk Factors of Primary Glaucoma in the Singapore Indian Eye Study
2021, Ophthalmology Glaucoma
Citation Excerpt :
First, a modest response rate of 75.5% occurred in the follow-up study. This is slightly lower compared with other population-based incidence studies, such as the Tema Eye Study (80.3%), the Los Angeles Latino Eye Study (76.6%), and the Chennai Eye Study (81.3%), and potentially could bias the incidence outcomes of the study.12,18,20 Second, because the participants who returned to the 6-year follow-up visit were younger (mean age, 56.5 years) than those who did not return (mean age, 60.1 years), the incidence reported is likely to be an underestimate.
To determine the 6-year incidence of primary glaucoma and its risk factors in an Indian population in Singapore.
Cohort population-based study.
Indian adults between 40 and 80 years of age living in Singapore. A total of 3400 participants underwent the baseline examination between 2007 and 2009. Of them, 2200 (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.
Incidences of primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).
The age-standardized incidences of primary glaucoma, POAG, and 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) or suspected primary angle closure (n = 101), the incidence of PACG developing was 1.82% (95% CI, 0.37%–9.68%). Baseline factors associated significantly with risk of primary glaucoma developing included older age (per decade; odds ratio [OR], 1.84; 95% CI, 1.44–2.36; P < 0.001), larger vertical cup-to-disc ratio (per 0.1 unit; OR, 2.78; 95% CI, 2.12–3.64; P < 0.001), and higher IOP (per millimeter of mercury; OR, 1.25; 95% CI, 1.13–1.38; P < 0.001). However, 71 of 85 eyes (84.5%) diagnosed with incident glaucoma had IOP of less than 21 mmHg at the time of examination.
Our study showed 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.
Glaucoma at the Center of the Earth
2019, Advances in Ophthalmology and Optometry
Eight-Year Incidence of Open-Angle Glaucoma in the Tema Eye Survey
2019, Ophthalmology
Citation Excerpt :
The response rate was 80.3% as a result of a concerted effort by the staff and community leaders to find the participants via phones, home visits, or third parties. It is comparable with rates in Barbados (81%–85%),25 India (81.3%),26 Sweden (78%–84%),27 and the United States (76.6%).28 From a case detection perspective, it is very unlikely that our low nonresponse rate of 19.7% could have affected the incidence of OAG.
To determine the incidence of open-angle glaucoma (OAG) and its risk factors in the Tema Eye Survey in Ghana, West Africa.
Longitudinal, observational population-based study.
One thousand two hundred five of 1500 participants 40 years of age or older selected randomly from 5603 participants originally drawn from the population and who had undergone a baseline examination.
All participants underwent baseline and follow-up ophthalmologic examinations 8 years apart. Glaucoma diagnosis was determined based on the International Society for Geographical and Epidemiologic Ophthalmology criteria.
Incidence and odds ratio (OR).
The response rate was 80.3%. Of 1101 nonglaucomatous participants at baseline who had complete follow-up data, 4.6% (95% confidence interval [CI], 3.7%–5.2%) demonstrated OAG over the 8-year period, or 0.58% (95% CI, 0.4%–0.8%) per year. The 8-year incidence increased with age from 3.1% in those 40 to 49 years old to 7.0% in those 60 to 69 years old. Baseline risk factors for incident OAG were male gender (OR, 2.1; 95% CI, 1.1–4.0; P = 0.025), older age relative to those 40 to 49 years old (those 50–50 years old: OR, 2.6; 95% CI, 1.2–5.7; those 60–69 years old: OR, 4.3; 95% CI, 2.0–8.8; and for those 70 years of age and older: OR, 6.3; 95% CI, 2.6–15.4; all P < 0.001), higher intraocular pressure (IOP; OR, 1.4; 95% CI, 1.1–1.8; P < 0.001), larger vertical cup-to-disc ratio (OR, 5.8; 95% CI, 5.2–6.6; P < 0.001), and thinner central cornea (OR, 1.2; 95% CI, 1.03–1.5; P = 0.013). A separate analysis performed with central corneal thickness-based IOP correction did not change the outcome of the associative model of incident glaucoma.
The incidence of OAG is higher in this population than reported in nonblack populations outside Africa. This is important not only in Ghana and probably other West African countries but also wherever people of the West African diaspora reside. These data enhance our understanding of the epidemiologic factors of OAG in this setting and may serve as reference for public health policy and planning.
Longitudinal Cohort Study on the Incidence of Primary Open-Angle Glaucoma in Bai Chinese
2017, American Journal of Ophthalmology
The prevalence of primary open-angle glaucoma (POAG) in China has been reported previously, and was lower than that in white and black populations. However, the incidence of POAG in China has not been reported. Therefore, a longitudinal study was conducted to determine the 5-year cumulative incidence and predictors of POAG in China.
Population-based cohort study.
A total of 1520 participants (71.3% of the subjects in the baseline survey) of Bai ethnicity were examined and followed for 5 years. Glaucoma was defined based on the International Society of Geographical and Epidemiological Ophthalmology Classification criteria. Multivariable logistic regression models were fitted to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs).
A total of 19 new cases of POAG were detected. The 5-year cumulative incidence of POAG was 1.3% (95% CI, 0.7–1.9). In multivariate analyses, incident POAG was associated with baseline variables including increased age (OR, 4.3; 95% CI, 1.4–13.8; P = .02; 70 years or older vs 50–59 years), elevated IOP (OR, 3.5; 95% CI, 2.0–5.9; P < .001; per 10 mm Hg increase), lower education level (OR, 0.3; 95% CI, 0.1–0.8; P = .02; post–primary education vs no formal education), and the presence of myopia (OR, 3.4; 95% CI, 1.3–8.6; P < .01).
The average annual incidence of POAG in Bai Chinese was lower than that in populations of African descent and white race. The results are important to elucidate the racial/ethnic difference in POAG incidence and for the clinical management and health resource allocation in China.

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: Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

: Supported by Chennai Willingdon Corporate Foundation, Chennai, India.

^∗: Both authors (Lingam Vijaya, MS, and Ronnie George, MS) contributed equally as first authors.

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Original articlePredictors for Incidence of Primary Open-Angle Glaucoma in a South Indian Population: The Chennai Eye Disease Incidence Study

Objective

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Section snippets

Study Population

Results

Discussion

Ophthalmology

Ophthalmology

Ophthalmology

Ophthalmology

Ophthalmology

Ophthalmology

Ophthalmology

Ophthalmology

Ophthalmology

Ophthalmology

Med Hypotheses

The number of people with glaucoma worldwide in 2010 and 2020

Br J Ophthalmol

Glaucoma in India: estimated burden of disease

J Glaucoma

Importance of population-based studies in clinical practice

Indian J Ophthalmol

Risk factors for glaucoma onset and progression

Surv Ophthalmol

Original article
Predictors for Incidence of Primary Open-Angle Glaucoma in a South Indian Population: The Chennai Eye Disease Incidence Study