Methods and design of the Chennai Glaucoma Study

Indian Journal of Ophthalmology, 2008

Purpose: A community-based survey was conducted in Rajnandangaon district of Chhatt isgarh state of central India in 2001 to assess the prevalence of glaucoma in the age group of ≥35 years.

Innovative Publication, 2017

Introduction: Primary Open Angle Glaucoma causes damage to the fibers of optic nerve which results in permanent visual loss. There may not be any symptoms; this is dangerous because patient may become blind silently. Glaucoma caused by angle closure mechanism causes symptoms and patient seeks medical attendance early. Aims and Objectives: To study clinical types and Factors associated with the Glaucoma patients. Methodology: This was cross-sectional study of the patients reporting to ophthalmology outpatient department or admitted in the ophthalmology wards having symptoms suggestive of Glaucoma, at tertiary health care center during the year 2016. The patients underwent detailed elucidation of history and examination. All essential investigations were undertaken. Attention was also paid to monitor treatment response and follow up. As per above criteria total 64 patients were included into the study. Result: Majority of the Glaucoma patients were from older age group. As age increases the problem of Glaucoma was more prevalent. It was more frequent in Males. More patients had Open angle Glaucoma than close angle or narrow angle. The most common associated factors with Glaucoma patients were Diabetes followed by Systemic Hypertension; Phacomorphic; post Iridocyclitis; Steroid induced Glaucoma; Traumatic Glaucoma. Conclusion: The problem of Glaucoma was more common in Older age and in males. The most common associated factors with Glaucoma patients were Diabetes followed by Systemic Hypertension; Phacomorphic; post Iridocyclitis; Steroid induced Glaucoma; Traumatic Glaucoma. So these factors should be considered during diagnosis and management of Glaucoma patients.

Ophthalmology, 2008

Objective: To estimate the prevalence and risk factors of primary open-angle glaucoma (POAG) in an urban population and compare the same with that of our published rural population data in southern India.

PLOS ONE, 2013

Purpose: To assess the prevalence of glaucoma in rural Central India. Methods: The population-based Central India Eye and Medical Study is a population-based study performed in a rural region of Central India. The study included 4711 subjects (aged 30+ years). A detailed ophthalmic and medical examination was performed. Glaucoma was defined by glaucomatous optic disc morphology, and in a second step, by the criteria of the International Society of Geographical and Epidemiological Ophthalmology (ISGEO).

2008

Glaucoma is estimated to affect 60.5 million persons worldwide by the year 2010.1 The estimated prevalence of glaucoma for India is 11.9 million.2 These estimates have been derived from population based studies conducted worldwide. The availability of population based data from India is relatively recent as compared to Western countries. We present a summary of the findings from different population based studies in the country. These have been five populations based studies, three from the state of Tamil Nadu, one from Andhra Pradesh and one from Bengal (Table 1).2-6 Data from North India is unfortunately lacking. These studies have been carried out from 1993 to 2003. To our best knowledge at least one more population based study (from Central India) is underway. All these studies have used differing methodology and diagnostic criteria for glaucoma. To improve comparability the prevalence reported by different studies has been age standardized to the population of India (2001 censu...

Ophthalmology, 2003

To determine the prevalence of glaucoma and risk factors for primary open-angle glaucoma in a rural population of southern India. Design: A population-based cross-sectional study. Participants: A total of 5150 subjects aged 40 years and older from 50 clusters representative of three southern districts of Tamil Nadu in southern India. Methods: All participants had a comprehensive eye examination at the base hospital, including visual acuity using logarithm of the minimum angle of resolution illiterate E charts and refraction, slit-lamp biomicroscopy, gonioscopy, applanation tonometry, dilated fundus examinations, and automated central 24-2 full-threshold perimetry. Main Outcome Measures: Definite primary open-angle glaucoma (POAG) was defined as angles open on gonioscopy and glaucomatous optic disc changes with matching visual field defects, whereas ocular hypertension was defined as intraocular pressure (IOP) greater than 21 mmHg without glaucomatous optic disc damage and visual field defects in the presence of an open angle. Manifest primary angle-closure glaucoma (PACG) was defined as glaucomatous optic disc damage or glaucomatous visual field defects with the anterior chamber angle partly or totally closed, appositional angle closure or synechiae in the angle, and absence of signs of secondary angle closure. Secondary glaucoma was defined as glaucomatous optic nerve damage and/or visual field abnormalities suggestive of glaucoma with ocular disorders that contribute to a secondary elevation in IOP. Results: The prevalence (95% confidence interval) of any glaucoma was 2.6% (2.2, 3.0), of POAG it was 1.7% (1.3, 2.1), and if PACG it was 0.5% (0.3, 0.7), and secondary glaucoma excluding pseudoexfoliation was 0.3% (0.2,0.5). On multivariate analysis, increasing age, male gender, myopia greater than 1 diopter, and pseudoexfoliation were significantly associated with POAG. After best correction, 18 persons (20.9%) with POAG were blind in either eye because of glaucoma, including 6 who were bilaterally blind and an additional 12 persons with unilateral blindness because of glaucomatous optic neuropathy in that eye. Of those identified with POAG, 93.0% had not been previously diagnosed with POAG. Conclusions: The prevalence of glaucoma in this population is not lower than that reported for white populations elsewhere. A large proportion of those with POAG had not been previously diagnosed. One fifth of those with POAG had blindness in one or both eyes from glaucoma. Early detection of glaucoma in this population will reduce the burden of blindness in India.

Ophthalmology, 2008

To estimate the prevalence and risk factors of primary open-angle glaucoma (POAG) in an urban population and compare the same with that of our published rural population data in southern India. Design: Population-based cross-sectional study. Participants: Four thousand eight hundred subjects 40 years or older were selected using a multistage random cluster sampling procedure in Chennai city. Intervention: Three thousand eight hundred fifty (80.2%) subjects underwent a complete ophthalmic examination, including applanation tonometry, gonioscopy, pachymetry, optic disc photography, and automated perimetry. Main Outcome Measures: Glaucoma was diagnosed using the International Society of Geographical and Epidemiological Ophthalmology Classification. Results: The distribution of intraocular pressure (IOP) and vertical cup-to-disc ratio (VCDR) was obtained from the right eye of the 2532 subjects with normal suprathreshold visual fields. Mean IOP was 16.17 Ϯ3.74 mmHg (97.5th and 99.5th percentiles, 24 mmHg and 30 mmHg). The mean VCDR was 0.43Ϯ0.17 (97.5th and 99.5th percentiles, 0.7 and 0.8). One hundred thirty-five (64 men, 71 women) subjects had POAG (3.51%; 95% confidence interval [CI], 3.04-4.0). Primary open-angle glaucoma subjects (58.4Ϯ11.3 years) were older (PϽ0.0001) than the study population (54.8Ϯ10.6 years). One hundred twenty-seven (94%) subjects were diagnosed to have POAG for the first time. Two subjects (1.5%) were bilaterally blind, and 3 (3.3%) were unilaterally blind due to POAG. The urban population prevalence was more than that of the rural population (1.62%; 95% CI, 1.4%-1.8%; PϽ0.0001). In both populations, increasing IOP (per millimeter of mercury) and older age were associated with the disease. There was no association with gender, myopia, systemic hypertension, diabetes, or central corneal thickness. Conclusions: The prevalence of POAG in a Ն40-year-old south Indian urban population was 3.51%, higher than that of the rural population. The prevalence increased with age, and Ͼ90% were not aware of the disease.

Innovative Publication, 2016

Glaucoma is a group of disorders characterized by chronic progressive optic neuropathy resulting in irreversible visual loss. It is a second leading cause of blindness worldwide while it is third leading cause of blindness in India. The present study was carried out to study the prevalence of different types of glaucoma in rural population. In all cases, detailed clinical history and family history was taken. A thorough ophthalmic examination was carried out which includes visual acuity with snellen's chart, slit lamp examination, optic disc evaluation by slit lamp biomicroscopy and direct ophthalmoscopy, angle evaluation by gonioscopy, intraocular pressure (IOP) recording by Applanation tonometry, visual field analysis by Humphrey visual field analyser(24-2) and general medical examination. A total of 17792 patients were examined of which 133 (0.74%) of various type of glaucoma were diagnosed. It was noted that overall prevalence of primary open angle glaucoma was 0.26%, 0.06% for normal tension glaucoma, 0.06% for angle closure glaucoma and 0.03% for juvenile glaucoma. The prevalence of common type of secondary glaucoma was 0.15% for lens induced glaucoma, 0.06% for traumatic and 0.05% for aphakic glaucoma. We concluded that primary open angle glaucoma was more common with maximum number of cases in the age group of 56-75 years, average age being 61 years. High prevalence rate of glaucoma was due to poor health education, low socioeconomic status and inaccessibility of ophthalmologists specifically in rural and tribal areas.

Investigative Opthalmology & Visual Science, 2013

To determine the prevalence and types of glaucoma in an urban Singaporean Indian population. METHODS. The Singapore Indian Eye Study (SINDI) was a population-based, cross-sectional survey that examined 3400 (75.6% response) persons aged 40 to 80 years. Participants underwent a standardized examination including slit-lamp biomicroscopy, Goldmann applanation tonometry, and dilated optic disc assessment. Participants suspected to have glaucoma also underwent visual field examination (24-2 SITA standard, Humphrey Visual Field Analyzer II), gonioscopy, and repeat applanation tonometry. Glaucoma was defined according to International Society for Geographical and Epidemiologic Ophthalmology criteria. Of the 3400 participants, 78 (2.29%) had diagnosed glaucoma, giving an agestandardized prevalence of 1.95% (95% confidence interval [CI], 1.5%-2.5%). The agestandardized prevalence of primary open-angle glaucoma (POAG) was 1.25% (95% CI, 0.89%-1.73%), primary angle-closure glaucoma (PACG) 0.12% (95% CI, 0.04%-0.33%), and secondary glaucoma 0.55% (95% CI, 0.35%-0.86%). The mean IOP among the participants in the normal group in the study population was 15.6 6 2.6 mm Hg and 17.7 6 6.1 mm Hg in subjects with glaucoma (P ¼ 0.003). The mean central corneal thickness (CCT) in the normal study population was 540.31 6 33.79; the mean CCT in subjects with POAG (529.8 6 30.8 lm) was statistically different from the normal study group (P ¼ 0.003). CONCLUSIONS. The prevalence of glaucoma among Singaporean Indians 40 years of age and older in Singapore was 1.95%, approximately half that of the Chinese and the Malay persons in Singapore. As in other Asian studies, POAG was the main form of glaucoma accounting for nearly 60% of cases.

Indian Journal of Ophthalmology, 2016

Glaucoma, the leading cause of global irreversible blindness, is estimated to have affected over 60.5 million persons worldwide. The estimated prevalence for India was 11.9 million in a study conducted in the late 1990s; the number has only increased since. Urban and rural India differ in patient demographics, disease patterns, and access to ophthalmic care. The only glaucoma prevalence study from Eastern India examined 1269 subjects from a rural population. The purpose of the Hooghly River Glaucoma Study (HRGS) was to examine the prevalence of glaucoma in a larger rural and urban East Indian population to make the results comparable to other international landmark glaucoma prevalence studies. The HRGS was a population-based cross-sectional study. The Institutional Ethics Review Board approved the study that adhered to the tenets of the Declaration of Helsinki. The sample size required for a precise estimate of the prevalence of glaucoma was calculated based on the methodology of other prominent prevalence studies. Assuming a 3.5% prevalence of glaucoma based on the Andhra Pradesh Eye Diseases Study (APEDS), Vellore Eye Study, and Chennai Glaucoma Study (CGS) and a design effect of two, the required sample size (n) was calculated using Daniel's Formula. Kolkata city was our urban study area. The city is divided into 15 boroughs and 141 wards. [13] One division was randomly selected from each of these 15 boroughs and 8 divisions were randomly picked from those 15 divisions. The following areas of Kolkata constituted the eight randomly selected divisions: (i) Bidhan Sarani, (ii) C. R. Avenue, (iii) Rash Behari Avenue, (iv) Prince Anwar Shah Road, (v) Diamond Harbour Road, (vi) Circular Garden Reach Road, (vii) B. T. Road, and (viii) A. J. C. Bose Road. A simple random sample of 910 each from the above eight randomly selected divisions was enumerated to reach a sample size of 7248 for our urban population. The rural study area consisted of 28 contiguous villages from 13 Gram Panchayats in Balagarh Police Station of Hooghly district in West Bengal, which was within a 20 km radius surrounding the rural base hospital located at Dhobapara, Balagarh Police Station, in the village Kuliapara of this district.