International Society Of Geographical And Epidemiological Ophthalmology Research Articles

Incidence of primary open angle glaucoma in the Andhra Pradesh Eye Disease Study (APEDS).

To report 15-year incidence rate of primary open angle glaucoma (POAG) in the Andhra Pradesh Eye Disease Study (APEDS). A population-based longitudinal study was carried out at three rural study sites. Phakic participants aged ≥40 years who participated at baseline (APEDS I) and the mean 15-year follow-up visit (APEDS III) were included. A comprehensive ophthalmic examination was performed on all participants. Mean intraocular pressure (IOP) was average of IOPs of right and left eyes. The definition of glaucoma was based on the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) classification. The main outcome measure was incidence of POAG during the follow-up period in participants without glaucoma or suspicion of glaucoma at baseline. Data from the available and eligible participants from the original cohort (1241/2790; 44.4%) were analysed. The mean age (standard deviation) of participants at baseline was 50.2 (8.1) years; 580 (46.7%) were men. Thirty-six participants developed POAG [bilateral in 17 (47.2%)] over 15 years. The incidence rate of POAG per 100-person years (95% confidence interval) was 2.83 (2.6, 3.08). Compared to baseline, the reduction in mean IOP [median (range) mm Hg] was -0.75 (-7.5, 9) in participants with incident POAG and -2.5 (-14.5, 14.5) in those without. The inter-visit difference in mean IOP was a significant risk factor on logistic regression analysis. We report the long-term incidence of POAG in rural India. A longitudinal change in IOP, specifically a less pronounced reduction in IOP with increasing age, was a novel risk factor.

Prevalence and associated factors of glaucoma in the Russian Ural Eye and Medical Study

To assess the prevalence and associated factors of glaucoma in a Russian population. The population-based Ural Eye and Medical Study included 5899 (mean age 59.0 ± 10.7 years; range 40–94 years). Glaucomatous optic neuropathy was diagnosed using International Society of Geographical and Epidemiological Ophthalmology (ISGEO) criteria. Among 5545 participants with assessable optic disc photographs, 246 individuals [4.4%; 95% confidence interval (CI) 3.9, 5.0] had glaucoma, with open-angle glaucoma (OAG) in 177 individuals (3.2%; 95% CI 2.7, 3.7) and angle-closure glaucoma (ACG) in 69 individuals (1.2; 95% CI 1.0, 1.5), with IOP > 21 mmHg in 79 (32.1%) patients, and with 80 (32.5%) patients on glaucoma therapy. Glaucoma prevalence increased from 3/485 (0.6%; 95% CI 0.0, 1.3) in the age group of 40–45 years to 33/165 (20.0%; 95% CI 13.8, 26.2) in the group aged 80 + years. Higher OAG prevalence correlated with older age [odds ratio (OR) 1.07; 95% CI 1.04, 1.09; P < 0.001], longer axial length (OR 1.36; 95% CI 1.17, 1.58; P < 0.001), higher intraocular pressure (IOP) (OR 1.18; 95% CI 1.13, 1.23; P < 0.001), higher stage of lens pseudoexfoliation (OR 1.26; 95% CI 1.08, 1.47; P = 0.004) and lower diastolic blood pressure (OR 0.98; 95% CI 0.96, 0.99; P = 0.035). Higher ACG prevalence correlated with older age (OR 1.07; 95% CI 1.03, 1.11; P < 0.001), narrower anterior chamber angle (OR 0.81; 95% CI 0.77, 0.86; P < 0.001), and higher IOP (OR 1.30; 95% CI 1.23, 1.38; P < 0.001). Glaucoma caused moderate to severe vision impairment (MSVI) in 9 (4.9%; 95% CI 1.8, 8.1) out of 184 individuals with MSVI (OAG, n = 7; ACG, n = 2), and blindness in one (9.1%) of 11 blind individuals. In this population from Russia, two thirds of glaucoma patients were not on therapy, and in two thirds of the glaucoma patients IOP was ≤ 21 mmHg. Otherwise, glaucoma prevalence, OAG-to-ACG ratio, and glaucoma associations did not differ markedly from Caucasian and East Asian populations.

Case‐finding for angle closure: the diagnostic value of simple tests for estimating limbal and central anterior chamber depth

PurposeTo evaluate the diagnostic accuracy of limbal and central anterior chamber depth measurement for detecting gonioscopically narrow anterior chamber angles (ACAs).MethodsA total of 78 subjects with narrow or open ACAs underwent an assessment of anterior chamber depth at the temporal limbus by estimating depth as a percentage of peripheral corneal thickness (van Herick test) by one examiner and just‐touching‐slit‐length measurements of the central anterior chamber depth (Smith's test) by a second examiner. Diagnostic performance was compared with (a) a gonioscopy reference standard, performed by a third examiner using the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) definition of primary angle closure and (b) a classification based on clinical opinion of occludability. All examiners were masked regarding each subject's clinical status and other test results. Sensitivity, specificity, and partial area under the receiver operating characteristic curve (AUROC) were generated.ResultsThe van Herick grading cutoff of 25% or less and ISGEO gonioscopic classification achieved 80% (95% CI 65–89) sensitivity and 92% specificity (95% CI 80–97) for narrow angle detection, with specificity reaching 97% (95% CI 87–100) for a cutoff of less than or equal to 15%. Notably, with a gonioscopic classification based on clinical opinion of occludability, van Herick (≤25%) together with Smith's test (≤2.50 mm) detected 100% of narrow angle subjects.ConclusionsThe van Herick test provides good discrimination between narrow and open angles both alone, and in combination with the measurement of central anterior chamber depth. These tests show good potential for identifying individuals who may benefit from further gonioscopic assessment in a case‐finding or screening setting.

Percentage of primary open angle glaucoma in retinal vein occlusion patients

Background Researches determined that the pathogenesis of retinal vein occlusion (RVO) is associated with primary open angle glaucoma (POAG) in Caucasian population.However, the relationship between RVO and POAG in Asian population is unclear. Objective This study was to survey the percentage of POAG in RVO patients in China. Methods A prospective cross-sectional observational study based on hospital was performed.Three hundred and seventy five patients with newly diagnosed RVO by fluorescein fundus angiography (FFA) were consecutively enrolled in Peking University Third Hospital from October 2011 to May 2013, and gonioscopy was carried out in all the patients.Glaucoma was diagnosed according to the criteria of the International Society of Geographical and Epidemiological Ophthalmology (ISGEO). RVO was classified into central retinal vein occlusion (CRVO), hemicentral retinal vein occlusion (HRVO) and branch retinal vein occlusion (BRVO) based on fundus photograph and FFA, or classified into arteriovenous crossing RVO (AV-RVO), optic cup RVO(OC-RVO), optic nerve RVO without optical nerve head swelling (NONHS-RVO) and RVO with optical nerve head swelling (ONHS-RVO) based on the sites of venous occlusion.The percentages of POAG in different types of RVO were calculated.This study was approved by Ethic Committee of Peking University Third Hospital, and written informed consent was obtained from each patient before entering study cohort. Results Three hundred and seventeen RVO patients finished screening of glaucoma, with the response rate 84.5%.The percentage of POAG is 8.2% in RVO patients, including 7.1% in the CRVO patients, 23.5% in HRVO patients and 6.2% in BRVO patients.The percentage of POAG was significantly higher in OC-RVO patients (27.9%) and NONHS-RVO patients (13.2%) than that in AV-RVO patients (4.7%) and ONHS-RVO patients (1.3%) (all at P<0.05). Conclusions The overall percentage of POAG in RVO patients in China is 3-4 times higher than general population.Higher percentage of POAG is found in OC-RVO patients and NONHS-RVO patients, suggesting that pathogenesis of RVO is probably associated with the glaucomatous anatomic changes of optical nerve head. Key words: Glaucoma/statistics & numerical data; Retinal vein; Thrombosis/statistics & numerical data; Glaucoma, open angle; Retinal vein occlusion; Humans

The Prevalence of Open-Angle Glaucoma by Age in Myopia: The Korea National Health and Nutrition Examination Survey

ABSTRACTPurpose: To investigate the prevalence of open-angle glaucoma (OAG) in myopia by age.Materials and methods: A cross-sectional study using a stratified, multistage, probability cluster survey. Participants in the Korean National Health and Nutrition Examination Survey between 2010 and 2011 were included. A standardized protocol was used to interview every participant and perform comprehensive ophthalmic examinations. Glaucoma was diagnosed according to the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) criteria.Results: After adjusting for age and sex, there was a positive correlation between OAG prevalence and increasing myopic refractive error except in participants with hyperopia. Younger participants with higher myopic refractive error had higher OAG prevalence than older participants with lower myopic refractive error. Participants with high myopia (OR 3.90, 95% confidence interval (CI) 2.30–6.59) had significantly greater age- and sex-adjusted odd ratios (ORs) than did those with emmetropia who were younger than 60 years.Conclusions: These data suggest that OAG develops earlier in participants with high myopia than in others. There was a high prevalence of OAG in participants with high myopia, even in those 19–29 years of age. Therefore, OAG screening should be performed earlier in participants with high myopia than is suggested by traditional guidelines.

Noncontact Screening Methods for the Detection of Narrow Anterior Chamber Angles

Comparing diagnostic accuracy of biomicroscope techniques (van Herick and Smith's tests, evaluating limbal and central anterior chamber depth, respectively) and advanced imaging (Visante OCT and Pentacam) for detection of gonioscopically narrow anterior chamber angles (ACAs). A total of 78 subjects with narrow or open ACAs underwent four index tests, performed on both eyes by examiners masked to other test results. Diagnostic performance was compared with gonioscopy, using International Society of Geographical and Epidemiological Ophthalmology (ISGEO) definition of primary angle closure and a classification based on clinical opinion of occludability. Data were analyzed using both the eye and the individual as unit of analysis. Sensitivity, specificity, and partial area under the receiver operating characteristic curve (AUROC) were generated. Using the eye as the unit of analysis, the van Herick grading cutoff of 25% or less and ISGEO gonioscopic classification achieved 80% (confidence interval [CI] 65 to 89) sensitivity and 92% specificity (CI 80 to 97) for narrow angle detection, with specificity reaching 97% (CI 87 to 100) for a cutoff of less than or equal to 15%. Notably, with a gonioscopic classification based on clinical opinion of occludability, van Herick (≤25%) together with Smith's test (≤2.50 mm) detected 100% of narrow angle subjects. Of the three Pentacam parameters, anterior chamber volume achieved highest test sensitivity of 85% (CI 70 to 94) using the ISGEO definition. Visante OCT ACA had greatest partial AUROC at 90% specificity, also yielding sensitivity and specificity greater than 85% using the Youden-derived cutoff of less than or equal to 20.7°and ISGEO definition. Van Herick test and Visante OCT ACA exhibited best discrimination between narrow and open angles both alone, and in combination. Van Herick test affords advantages over Visante OCT, showing potential for identifying individuals who may benefit from further gonioscopic assessment in a case-finding or screening setting.

Nigeria Normative Data for Defining Glaucoma in Prevalence Surveys

ABSTRACTPurpose: To determine normative values for defining glaucoma in cross-sectional surveys in Nigerian adults.Methods: Multistage stratified cluster random sampling with probability-proportional-to-size procedures to select a nationally representative sample of 15,027 persons aged ≥40 years in 305 clusters across Nigeria. Systematic sampling of 1 in 7 participants gave 1759 who were examined in detail to construct a normative database. The normative subset was used to determine values for vertical cup/disc ratio (VCDR) and intraocular pressure (IOP) for glaucoma diagnosis according to the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) criteria. Examinations included visual field testing by frequency doubling technology (FDT), Goldmann applanation tonometry, and optic disc image grading by Moorfields Eye Hospital Reading Centre.Results: In the normative dataset, 1057/1759 persons (60.1%) had normal FDTs, and constituted the hypernormal. Of these, 851 had VCDR and 973 had IOP measurements taken in both eyes. For category 1 (structural and functional evidence of glaucoma), the 97.5th percentile VCDR was 0.7. For category 2 (advanced structural damage with unproven visual field loss), the 99.5th percentile VCDR was 0.75. In addition, asymmetry in VCDR was 0.1 difference at the 97.5th percentile and 0.2 difference at the 99.5th percentile. Category 3 criteria were used when the optic disc was not visible and field testing not possible; 99.5th percentile IOP is one criterion (28 mmHg).Conclusion: While these results do not differentiate between open-angle and angle-closure mechanisms, they can be applied to determine the prevalence of glaucoma in Nigeria and sub-Saharan African countries with similar sociodemographic characteristics.

Presentation of glaucoma in the greater Accra metropolitan area of Ghana.

This study addresses the prevalence and clinical presentation of patients with primary open angle glaucoma (POAG) in the greater Accra metropolitan area. This is a retrospective case series of 455 patients (813 eyes) at the Emmanuel Eye Clinic. Patients were diagnosed from May 2008 to Nov 2011. The definition of POAG conformed to the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) criteria. Information collected included basic demographic data, distribution of glaucoma subtypes, measured intraocular pressure (IOP), best corrected visual acuity (BCVA) and optic disc measurements. Nearly 24% presented blind in at least one eye. The average age was 56.7 +/-16.7 years and the average IOP was 33.9 mmHg +/- 12.7 mmHg for right eyes and 33.5 mmHg +/-12.0 mmHg for left eyes. The mean vertical cup to disc ratio (vCDR) was 0.83 for right eyes versus 0.82 for left eyes. A total of 32 patients (53 eyes) were diagnosed with normal tension glaucoma (NTG). Statistically significant differences between the NTG and high tension groups included age (45.3 +/- 16.7 vs. 56.7 +/-16.7, p<0.001), mean IOP (19.1 mmHg +/- 4.5 mmHg vs. 33.7 +/- 12.4 mmHg, p<0.001) and mean vCDR (0.76 +/- 0.17 vs. 0.83 +/-0.10, p<0.01). Comparing age-matched NTG patients with high tension glaucoma patients showed no significant difference in vCDR. The clinical presentation of POAG at the Emmanuel Eye Center is characterized by elevated IOP and grossly advanced optic neuropathy. Significant differences between high tension glaucoma and NTG were identified.

Open-angle Glaucoma in Filipino and White Americans

To compare the frequency of open-angle glaucoma (OAG) subtypes between Filipino and white Americans in a general ophthalmology clinic population. In this retrospective cross-sectional epidemiologic study with prospective sampling, medical charts of 1113 patients aged 40 years or older (513 Filipinos, 600 whites) seen in 2008 were randomly sampled from 2 private comprehensive ophthalmology clinics. Glaucoma was diagnosed based on optic nerve appearance, visual field defects, and other ocular findings using the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) scheme. The normal-tension subtype of OAG [normal-tension glaucoma (NTG)] was defined by intraocular pressure ≤21 mm Hg as determined by review of medical records. NTG comprised a greater proportion of all glaucomatous disease in Filipino subjects [Filipino (F) vs. white (W): 46.7% vs. 26.8%; P=0.02]. Filipinos were more commonly diagnosed with OAG and NTG than whites (F vs. W: OAG, 11.9% vs. 8.2%; NTG, 6.8% vs. 2.5%; P=0.04, 0.001, respectively). There was no significant difference in central corneal thickness between Filipino and white subjects with NTG (P=0.66). Both OAG and NTG may be more common in Filipino Americans than in white Americans with the propensity for NTG being particularly high in the former relative to the latter group.

Prevalence and associated factors of glaucoma in rural central India. The Central India Eye and Medical Study.

PurposeTo assess the prevalence of glaucoma in rural Central India.MethodsThe 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).ResultsOptic disc photographs were available for 4570 (97.0%) subjects. Glaucoma was detected in 122 subjects (51 unilateral) (2.67% (95%CI: 2.20, 3.14). Glaucoma prevalence for the age groups of 30–39yrs, 40–49yrs, 50–59yrs, 60–69yrs, 70–79yrs, and 80+ years was 0.54% (95%CI: 0.11, 0.98), 1.03% (95%CI: 0.49, 1.57), 1.40% (95%CI: 0.58, 2.23), 6.62% (95%CI: 4.92, 8.31), 8.71% (95%CI: 5.55, 11.75), and 14.3% (95%CI: 4.13, 24.4), respectively. In multivariable analysis, glaucoma was associated with higher age (P<0.001), lower body mass index (P = 0.025), lower blood hemoglobin concentration (P = 0.03), higher intraocular pressure (P<0.001), disc hemorrhages (P<0.001), higher prevalence of myopic retinopathy (P<0.001), lower level of education (P = 0.03), longer axial length (P<0.001), thinner retinal nerve fiber layer (P<0.001), higher vertical cup/disc diameter ratio (P<0.001), and narrow anterior chamber angle (P = 0.02). Ratio of open-angle glaucoma to angle-closure glaucoma was 7.7:1 (1.93% (95%CI: 1.64, 2.22) to 0.24% (95%CI: 0.14, 0.34)). Using the ISGEO criteria, glaucoma prevalence was 2.8% (95%CI: 2.3, 3.3) with a less clear association with older age.ConclusionsGlaucoma prevalence in remote rural Central India is comparable to other regions. Associated factors were older age, lower body mass index, lower blood concentration of hemoglobin, lower level of education, higher intraocular pressure, disc hemorrhage, myopic retinopathy, and longer axial length. The ratio of open-angle glaucoma to angle-closure glaucoma was about 8:1.

Profile of angle closure glaucoma in the Gangetic Delta

Purpose: To study the clinical profile of the types of primary angle closure patients in a rural and urban population in Eastern India. Materials and Methods: International Society of Geographical and Epidemiological Ophthalmology (ISGEO) classification scheme was used to categorize patients. Clinic records of patients diagnosed as primary angle closure were reviewed. Clinical data including prior management was collected and analyzed. Main Outcome measures were age, sex, best corrected visual acuity (BCVA), intraocular pressure (IOP), gonioscopy, optic disc assessment and Frequency Doubling Perimetry(FDT). Logistic regression model and receiver operating curve (ROC) were calculated for predictors of type of glaucoma. Results: 1904 eyes; males:982 , females: 922) were diagnosed to have various subtypes of angle closure. Mean (±SD) age at presentation was significantly higher for males (56.54 ± 11.51 years) as compared to females (52.76 ± 10.46 years) (P < 001). Primary angle closure glaucoma (PACG) was most frequently diagnosed subtype (45.24%) followed by Primary angle closure (PAC) (40.46%) and Primary angle closure suspect (PACS) (14.30%) respectively. The three subtypes differed significantly among their mean IOP (on ANOVA, F = 12.04; P < 001). ROC yielded a very high AUC of 0.96 with strong discriminatory ability for PACG. Conclusion: In our population based study, the significant predictors for the outcome of PACG included male gender, diminution of vision, the presence of pain and worsening grades of BCVA. Nearly half of PACG presented with advanced disease.

Prevalence and risk factors for angle-closure disease in a rural Northeast China population: a population-based survey in Bin County, Harbin

To estimate the prevalence of primary angle-closure glaucoma (PACG), primary angle closure (PAC) and primary angle-closure suspect (PACS) and associated risk factors for PACG in a rural population in Northeast China. A population-based survey was conducted in Bin County, Harbin, Northeast China. Glaucoma was diagnosed using the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) criteria. All subjects underwent a complete ophthalmic examination. A total of 4956 (86.01%) of 5762 subjects aged 40 years or older were examined. The mean intraocular pressure (IOP) of the right eyes was 14.0 mmHg. The mean vertical cup-to-disc ratio of the right and the left eyes was 0.31 and 0.31, respectively. The prevalence of PACG, PAC and PACS was 1.57% [95% confidence interval (CI), 1.469-1.671], 1.33% (95% CI, 1.236-1.424), and 4.68% (95% CI, 4.541-4.819), respectively. Among all PACG subjects, 42 (53.84%) had elevated IOP >21 mmHg in either eye and 37 (47.44%) had been treated by laser, surgical iridectomy or trabeculectomy. Sixty-four subjects (82.05%) had vision impairment of varying degrees. Multivariate analysis revealed that old age, family history of PACG, constipation and IOP were significant independent risk factors. Primary angle-closure glaucoma was a disease of high prevalence in rural Northeast China. Old age, family history of PACG, constipation and IOP were significant independent risk factors for PACG.

Classification of primary angle closure disease

Primary angle closure disease, PACD, has had a plethora of classifications and terminologies. The International Society of Geographical and Epidemiological Ophthalmology (ISGEO) classification was a simple classification, extremely useful in surveys, but could not be clinically applied because of the varied presentation of PACD. Reviewing the literature, it was seen that the landmarks in progression of PACD were an anatomical predisposition; iridocorneal apposition/adhesions; chronic rise in intraocular pressure (IOP), despite an iridotomy; and glaucomatous optic neuropathy. Therefore, a staging system for PACD is proposed. PACD suspect--occludable angle; PACD I--occludable angle with evidence of closure, but a normal IOP after iridotomy; PACD II--peripheral anterior synechiae in an occludable angle with a chronically raised IOP after iridotomy, with or without a suspicious optic nerve head; and PACD III--peripheral anterior synechiae in an occludable angle, with a raised IOP after iridotomy, and glaucomatous optic neuropathy. This proposed classification has amalgamated all the clinically described subtypes of PACD--subacute, acute, chronic, symptomatic, and asymptomatic--into a staging, based on extent of damage to the outflow channels and optic nerve head, providing a basis for standardized therapy and possibly a quantifiable long-term prognosis.

The 97.5th and 99.5th Percentile of Vertical Cup Disc Ratio in the United States

The International Society of Geographical and Epidemiological Ophthalmology (ISGEO) suggests a case definition for the prevalence studies of glaucoma based on the 97.5th and 99.5th percentile of vertical optic cup distribution among the evaluated population. Although multiple studies evaluating the prevalence of glaucoma have been undertaken in the last 20 years, case definitions have varied, and data on the underlying population distribution are sparse. This study evaluates the population distribution of 97.5th and 99.5th percentile of vertical cup disc ratio (VCDR) and VCDR asymmetry (VCDRA) in the US population and its association with demographic characteristics, self-reported glaucoma, and visual field. The National Health and Nutrition Examination Survey (NHANES) is a nationally representative sample of the US population, which during the years 2005 to 2008 collected frequency doubling technology screening fields and digital fundus photography. Accounting for the complex design of the NHANES population, estimates of the 97.5th and 99.5th percentile of VCDR and VCDRA were calculated, and national estimates of glaucoma prevalence were generated. Associations between disc characteristics, demographic variables, and self-reported glaucoma were explored. Approximately 2.11% (95% confidence interval, 1.55 to 2.67) of the US population older than 40 years has glaucoma based on ISGEO criteria. A much larger 5.13% (95% confidence interval, 4.43 to 5.85) of the US population older than 40 years self-reports having glaucoma. Based on the estimates from NHANES, 6.89% of the population has a VCDR or VCDRA >97.5th percentile in either eye or OU. For the at-risk population with VCDR/VCDRA above the 97.5th percentile, <20% reported having glaucoma, whereas for those at the 99.5th percentile, <50% reported having glaucoma. The prevalence of glaucoma from NHANES based on ISGEO criteria produces similar population estimated to other population-based studies. Self-reported glaucoma is ∼2.4 times more common than what the prevalence estimates suggest.

Prevalence of Glaucoma in North China: The Beijing Eye Study

To assess the prevalence of glaucoma in adult Chinese. Population-based study. The Beijing Eye Study in 2001 included 4439 subjects with an age of 40+ years. Glaucoma was determined using the ISGEO (International Society of Geographical and Epidemiological Ophthalmology) classification scheme. Glaucoma was detected in 158 subjects (3.7%, 95% confidence interval [CI] 3.1%-4.2%), in which open-angle glaucoma (OAG), primary angle-closure glaucoma (PACG), and secondary glaucoma (SG) accounted for 2.6% (95% CI 2.1%-3.0%), 1.0% (95% CI 0.7%-1.3%), and 0.07% (95% CI 0%-0.1%), respectively. The overall glaucoma prevalence for the age groups of 40 to 49 years, 50 to 59 years, 60 to 69 years, and 70+ years was 2.2%, 2.5%, 4.4%, and 9.5%, respectively. Glaucoma prevalence increased significantly with age (P = .001), myopic refractive error (P < .001), and intraocular pressure (P < .001). The age-standardized prevalence of OAG, PACG, and SG was 2.5%, 1.0%, and 0.1%, respectively. Prevalence of glaucoma-related bilateral blindness or unilateral blindness was significantly (P = .02 and P = .03) higher in PACG than in OAG. Frequency of glaucoma-associated blindness and low vision was significantly higher in the rural area than in the urban region (6/62 vs 2/96, P = .04). In the adult population of Greater Beijing, glaucoma prevalence was 3.6% and increased with age, myopic refractive error, and intraocular pressure. Glaucoma prevalence of 3.6% was comparable with figures from Caucasian populations. The ratio of OAG to PACG of 2.6:1 agrees with recent other studies from East Asia. Glaucoma-related blindness and low vision occurred significantly more often in PACG than in OAG.

The Chennai glaucoma study: Prevalence and risk factors for glaucoma in cataract operated eyes in urban Chennai

We report the prevalence and risk factors for glaucoma among aphakes and pseudophakes in 3850 subjects who participated in a population-based study in urban south India. The subjects underwent an ophthalmic examination including applanation tonometry, gonioscopy, optic disc evaluation and frequency doubling perimetry. Glaucoma was diagnosed using the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) criteria. Thirty eight, 15 aphakes and 23 pseudophakes (0.99% of 3850 subjects) of the 406 persons who had undergone cataract surgery were diagnosed with glaucoma. Aphakes/pseudophakes were at higher risk of glaucoma as compared to the phakic population (Odds Ratio: 2.71, 95% CI: 1. 94, 3.38, p=0.001). On multivariate analysis, older age and higher intra ocular pressure were risk factors for glaucoma. Blindness attributable to glaucoma was detected in 20% of aphakic and 4.3% of pseudophakic eyes. Glaucoma was a significant cause of morbidity in those who had undergone cataract surgery in this urban population.

Profile of angle closure in a tertiary care center in north India.

Purpose:To study the demographic and clinical profile of the types of primary angle closure patients presenting at a tertiary care center in North India.Materials and Methods:Clinic records of patients diagnosed as primary angle closure were reviewed. International Society of Geographical and Epidemiological Ophthalmology (ISGEO) classification scheme was used to categorize patients. Demographic and clinical data including prior management was collected and analyzed. Main Outcome measures were age, sex, symptomatology, best corrected visual acuity (BCVA), intraocular pressure (IOP), gonioscopy, optic disc assessment and visual field defects. Logistic regression model and receiver operating curve (ROC) were calculated for predictors of type of glaucoma.Results:Eight hundred and fourteen patients (1603 eyes; males: 380, females: 434) were diagnosed to have various subtypes of angle closure. Mean (±SD) age at presentation was significantly higher for males (57.57 ± 11.62 years) as compared to females (53.64 ± 10.67 years) (P < 0001). Primary angle closure glaucoma (PACG) was most frequently diagnosed subtype (49.38%) followed by Primary angle closure (PAC) (39.68%) and Primary angle closure suspect (PACS) (10.93%) respectively. The three subtypes differed significantly among their mean IOP (on ANOVA, F = 14.04; P < 0001 using Greenhouse-Geisser correction). Univariate analysis was done to find significant predictors for the outcome of PACG. Logistic regression model and ROC containing the significant predictors yielded a very high AUC of 0.93 with strong discriminatory ability for PACG.Conclusion:In our hospital-based study, the significant predictors for the outcome of PACG included male gender, diminution of vision, the presence of pain and worsening grades of BCVA. Nearly half of PACG presented with advanced disease. In spite of one-third of the patients being diagnosed as angle closure prior to referral, only 8.34% had iridotomy (laser or surgical) done.

Prevalence and Clinical Characteristics of Glaucoma in Adult Chinese: A Population-Based Study in Liwan District, Guangzhou

To assess the prevalence and mechanism of glaucoma in adults living in an urban area of southern China. Random clustering sampling was used to identify adults aged 50 years and over in Liwan District, Guangzhou. Glaucoma was diagnosed with the ISGEO (International Society of Geographical and Epidemiological Ophthalmology) classification scheme. All subjects underwent gonioscopy. In the study, 1504 subjects (75.3% participation rate) were examined, with a crude prevalence of all glaucoma of 3.8% (95% confidence interval [CI], 2.8%-4.8%). Primary open-angle glaucoma (POAG) was found in 2.1% (95% CI, 1.4%-2.8%) and primary angle-closure glaucoma (PACG) in 1.5% (95% CI, 0.8%-2.1%). The prevalence of all glaucoma was significantly higher in older people and men. POAG was more common than PACG in this southern Chinese population, with rates similar to those reported in Chinese Singaporeans. The age-adjusted rate of POAG was similar to that found in European-derived populations, but PACG was more common among Chinese, indicating that there is a large burden of glaucoma in the Chinese people.