A Population-based Survey of the Prevalence and Types of Glaucoma in Nepal: The Bhaktapur Glaucoma Study

Anterior Segment OCT for Detection of Narrow Angles: A Community-Based Diagnostic Accuracy Study

PURPOSE

To assess the diagnostic accuracy of anterior segment OCT (AS-OCT) screening for detecting gonioscopically narrow angles.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

A stratified random sample of individuals aged ≥ 60 years, selected from a door-to-door census performed in low-lying Nepal.

TESTING

Participants underwent AS-OCT, posterior segment OCT, and intraocular pressure (IOP) testing in the community. Those meeting referral criteria in either eye were invited to have a comprehensive eye examination including gonioscopy. Referral criteria included (i) the lowest 2.5% of AS-OCT measurements, (ii) retinal OCT results suggestive of glaucomatous optic neuropathy, diabetic retinopathy, or age-related macular degeneration, and (iii) elevated IOP.

MAIN OUTCOME MEASURES

Sensitivity and specificity of 5 semiautomated AS-OCT parameters relative to gonioscopically narrow angles, defined as the absence of visible trabecular meshwork for ≥ 180° on nonindentation gonioscopy.

RESULTS

Of 17 656 people aged ≥ 60 years enumerated from 102 communities, 12 633 (71.6%) presented for AS-OCT testing. Referral was recommended for 697 participants based on AS-OCT criteria and 2419 participants based on other criteria, of which 858 had gonioscopy performed by a glaucoma specialist. Each of the 5 AS-OCT parameters offered good diagnostic information for predicting eyes with gonioscopically narrow angles, with areas under the receiver operating characteristic curve ranging from 0.85 to 0.89. The angle opening distance at 750 μm from the scleral spur (AOD750) provided the most diagnostic information, providing an optimal sensitivity of 87% (95% confidence interval [CI], 75%-96%) and specificity of 77% (71%-83%) at a cutpoint of 367 μm, and a sensitivity of 65% (95% CI, 54%-74%) when specificity was constrained to 90% (cutpoint, 283 μm).

CONCLUSIONS

On AS-OCT, the AOD750 parameter detected approximately two-thirds of cases of gonioscopically narrow angles when test specificity was set to 90%. Although such a sensitivity may not be sufficient when screening solely for narrow angles, AS-OCT requires little additional effort if posterior segment OCT is already being performed and thus could provide incremental benefit when performing OCT-based screening.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.

Prevalence Ratio of Primary Angle-Closure and Primary Open-Angle Glaucoma in Asian Population: A Meta-Analysis and Multiple Meta-Regression Analysis

PURPOSE

To investigate the prevalence ratio of primary angle-closure glaucoma (PACG) and primary open-angle glaucoma (POAG) in the Asian population.

METHODS

Systematic searches of PubMed, Embase, and Cochrane databases for population-based studies in Asia published until August 5, 2022. We conducted a meta-analysis for PACG to POAG prevalence ratio using inverse variance-weighted random-effects meta-analyses so as to combine the study-specific measures of association. Between-study outcome variation (i.e., heterogeneity) was quantified with the I2 statistic. The multiple meta-regression analyses were performed in order to further account for the reasons for heterogeneity.

RESULTS

Twenty studies, with a total study population of 52,522 individuals, had been conducted in 13 countries. The pooled PACG to POAG prevalence ratio was 2.204 (95% confidence interval, 1.617-3.004) with high heterogeneity (p < 0.001). In multiple meta-regression model, prevalence of POAG is the most important predictor for heterogeneity (model importance, 0.954), followed continent (0.508), and publication year (0.222). For every additional elevation of POAG prevalence (i.e., increase of 1.0%), the PACG to POAG prevalence ratio is expected to rise by 0.471.

CONCLUSIONS

We estimated the pooled PACG to POAG prevalence ratio in the Asian population. The POAG prevalence is the most important factor to determine the PACG to POAG prevalence ratio.

A Novel Visual Field Screening Program for Glaucoma With a Head-Mounted Perimeter

PRCIS

A novel visual field screening program with a head-mounted perimeter 'imo' could detect glaucoma at all stages in a short time with high accuracy.

PURPOSE

The present study aimed to examine the accuracy and availability of a novel glaucoma visual field screening program using a head-mounted visual perimeter 'imo.'

PARTICIPANTS AND METHODS

Eyes of 76 non-glaucoma participants and 92 glaucoma patients were examined. All patients underwent visual field tests using the Humphrey Visual Field Analyzer (30-2 or 24-2 Swedish Interactive Thresholding Algorithm standard program) and imo (the visual field screening program). We evaluated five visual field screening program indicators: sensitivity, specificity, positive predictive value, negative predictive value, and testing time. We also evaluated the ability of this visual field screening program to differentiate between glaucoma patients and normal controls using the receiver operating characteristic curves and areas under the receiver operating characteristic curves.

RESULTS

The sensitivity, specificity, positive predictive value, and negative predictive value of the visual field screening program were 76%-100%, 91%-100%, 86%-89%, and 79%-100%, respectively. The visual field screening program test time was 46±13 seconds for normal controls and 61±18, 82±21, and 105±16 econds, respectively for mild, moderate, and advanced-stage patients. The areas under the receiver operating characteristic curves were 0.77, 0.97, and 1.0 in the mild, moderate, and advanced stages, respectively.

CONCLUSIONS

Visual field screening using a head-mounted perimeter 'imo' detected glaucoma at all stages in a short time with high accuracy.

Anterior Segment Biometry in Primary Angle Closure Glaucoma Patients with Visual Field Progression: Comparison between Malays and Chinese

Objective

To compare anterior segment biometry parameters in progress and non-progress primary angle closure glaucoma (PACG) among Malay and Chinese patients.

Materials and methods

A cross-sectional study was conducted between November 2015 and December 2016 involving 75 patients with PACG (43 Malays and 32 Chinese) who were recruited from a single glaucoma center in Malaysia. Ocular examination included anterior segment biometry measurements on the selected eye. Axial length (AL) and anterior chamber depth (ACD) measurement was done using a noncontact partial coherence interferometer (IOL Master, Carl Zeiss, Germany). Anterior chamber angle (ACA) was measured by Anterior Segment-OCT (Spectralis Heidelberg, Germany). Humphrey visual field (HVF) 24-2 analysis of the same eye was conducted and compared with the HVF when diagnosis was made. Progression of PACG patients was assessed according to the Hodapp, Parrish and Anderson's (HPA) classification, they were then divided into progress and non-progress groups. Comparison of anterior segment biometry parameters between Malay and Chinese PACG patients with and without progression was analyzed using independent T test. Multivariate ANOVA analysis was used to compare the anterior segment parameters between progress and non-progress PACG patients, with adjustment for age, gender, lens status, family history and presence of diabetes mellitus.

Results

Chinese PACG patients have significant shorter AL (22.18 mm ± 0.76) and narrower ACA (11.96° ± 6.00) compared to Malay PACG patients. Among the progress group, Chinese PACG patients have significant shorter AL, shallower ACD and narrower ACA compared to Malays. However, after controlling for confounding factors, there was significant difference in ACA between Malay and Chinese PACG. There was also no significant difference of ocular biometry measurement between Chinese and Malay patients in progress and non-progress group.

Conclusion

There was racial influence in ocular biometry measurement in PACG patients. Chinese have significant narrower ACA compared to Malays. Serial AS-OCT monitoring is important in management of PACG.

How to cite this article

Neoh FP, Azhany Y, Siti-Azrin AH, et al. Anterior Segment Biometry in Primary Angle Closure Glaucoma Patients with Visual Field Progression: Comparison between Malays and Chinese. J Curr Glaucoma Pract 2023;17(1):3-8.

Blindness in glaucoma: primary open-angle glaucoma versus primary angle-closure glaucoma-a meta-analysis

AIM

To estimate the risk of blindness with primary angle-closure glaucoma (PACG) compared to primary open-angle glaucoma (POAG) in those population-based studies that reported blindness rates for both PACG and POAG.

METHOD

A systematic search was performed in PubMed for articles published in English between 2000 and 2020 reporting the prevalence of POAG as well as PACG among various ethnic populations. A study was included if it was (1) population-based (2) had published prevalence and blindness rates for both PACG and POAG in the same cohort. (3) Glaucoma was defined as per the International Society for Geographical and Epidemiological Ophthalmology (ISGEO) criteria. The proportion of blindness for both POAG and PACG for each study and the cumulative proportion taking all the studies were calculated.

RESULTS

We included 23 studies with 78,434 participants. POAG was diagnosed in 1702 persons with 151 (8.9%) blind. There were 724 cases of PACG with 196 (27.0%) blind. The risk ratio of blindness in PACG to POAG varied from 0.73 to 10.6 among the studies. The cumulative risk ratio was 2.39 (95% confidence interval (CI); 1.99, 2.87). Risk ratios for studies including visual field restriction while defining blindness were similar to studies that did not (1.92 vs 2.64, P = 0.11). Risk ratios were also similar for studies that used greater than 2 instead of 3 or more quadrants of iridotrabecular contact to define angle closure (2.79 vs 2.25).

CONCLUSION

Primary angle-closure disease is more likely to be associated with blindness.

Risk factors for glaucoma are reflected in abnormal responses to frequency-doubling technology screening in both normal and glaucoma eyes

The frequency-doubling technology (FDT) screening test (FDT-C-20-1) has adopted in many recent population-based glaucoma surveys, but factors associated with false-positive (FP) responses to FDT-C-20-1 in normal eyes and false-negative (FN) responses in glaucoma eyes were not known. These factors were investigated in a population-based setting using the data from 3805 normal eyes (2381 subjects) and 272 eyes with definite glaucoma (215 subjects) in the Kumejima Study participants with reliable FDT-C-20-1 results. Considering the presence of at least one abnormal test point (P < 0.01) as abnormal, the specificity and sensitivity of FDT-C-20-1 for glaucoma were 91.8% (95% confidence interval, 91.1 ~ 92.5) and 56.3% (47.0 ~ 62.5), respectively. Multivariate linear mixed-model logistic regression analysis showed correlations with older age, worse visual acuity, greater β-peripapillary area (P < 0.001 for all comparisons) and more myopic refraction (P = 0.030) with the FP responses in normal eyes, and normal-tension glaucoma (P = 0.043), a better mean deviation value of Humphrey perimetry (P = 0.001), larger rim area (P = 0.041), and absence of disc hemorrhage (P = 0.015) with the FN responses in glaucoma eyes. In a population-based setting, abnormal responses to FDT-C-20-1 indicate the presence of a risk factor for glaucoma in normal eyes and risk factors for more rapid progression in glaucoma eyes.

The Prevalence of Glaucoma in the Jirel Ethnic Group of Nepal

Glaucoma is one of the leading causes of blindness worldwide with individuals in Asia disproportionately affected. Using a cross-sectional study design as part of the Jiri Eye Study, we assessed the prevalence of glaucoma in the Jirel population of Nepal and provide new information on the occurrence of glaucoma in south central Asia. Over a four-year period, 2,042 members of the Jirel population, aged 18 years and older, underwent a detailed ocular examination. Glaucoma was diagnosed using the International Society of Geographical and Epidemiological Ophthalmology criteria. The mean (SD) age at exam was 42.3 (16.7) years and 54.1% of the sample was female. In the total sample, the mean (SD) intraocular pressure (IOP) and vertical cup-to-disc ratio (VCDR) was 14.55 (2.42) mmHg and 0.31 (0.15), respectively. The 97.5th and 99.5th percentile for IOP and VCDR was 20 mmHg and 22 mmHg, and 0.7 and 0.8, respectively. The overall prevalence of glaucoma in the population was 2.30% (n = 47). Of these 47 individuals, 37 (78.7%) had primary open angle glaucoma, 6 (12.8%) had primary angle closure glaucoma, and 4 (8.5%) had secondary glaucoma. There was a significant (p = 5.86×10-6) increase in the prevalence of glaucoma with increasing age overall and across glaucoma subtypes. Six individuals with glaucoma (12.8%) were blind in at least one eye. Of the individuals with glaucoma, 93.6% were previously undiagnosed. In individuals aged 40 years or older (n = 1057, 51.4% female), the mean (SD) IOP and VCDR was 14.39 (2.63) mmHg and 0.34 (0.16), respectively, and glaucoma prevalence was 4.16% (n = 44). The prevalence of glaucoma and undiagnosed disease is high in the Jirel population of Nepal. This study will inform strategies to minimize glaucoma-associated burden in Nepal.

Home-Based Perimetry for Glaucoma: Where Are We Now?

PURPOSE

To systematically summarize the current literature on home-based perimeters for glaucoma.

METHODS

A systematic review was conducted in accordance with the PRISMA-DTA checklist. Studies reporting portable perimeters designed for home use were retrieved from electronic databases and handsearching of reference lists of relevant publications. Studies reporting diagnostic accuracy data were evaluated with the QUADAS-2 tool and using standard automated perimetry as the reference standard. Other aspects of the technology such as detection of disease progression and patient acceptability were also included. Data were reported in a narrative and tabular format.

RESULTS

Of 18 included studies, 10 evaluated tablet-based perimeters, 4 evaluated web-based perimeters, and 4 evaluated head-mounted displays. Most studies used a clinic or laboratory setting. All studies reporting diagnostic accuracy data had high risk of bias in at least one domain. Across studies, sensitivity ranged from 54% in detecting mild to 91% in detecting moderate/severe glaucoma patients from controls, while specificity was between 50% and 100% for any form of glaucoma. The reported acceptability was high but had high risk of bias.

CONCLUSION

Several promising technologies designed for home-based perimetry have been reported. Current studies used a controlled setting in highly selected populations. There is uncertainty on the performance and value of home-based perimetry for glaucoma. Additional efforts are required to elucidate the ability of the home-based perimeters to detect glaucoma and disease progression in real life situations.

Handheld chromatic pupillometry can accurately and rapidly reveal functional loss in glaucoma

BACKGROUND/AIMS

Early detection and treatment of glaucoma can delay vision loss. In this study, we evaluate the performance of handheld chromatic pupillometry (HCP) for the objective and rapid detection of functional loss in glaucoma.

METHODS

In this clinic-based, prospective study, we enrolled 149 patients (median (IQR) years: 68.5 (13.6) years) with confirmed glaucoma and 173 healthy controls (55.2 (26.7) years). Changes in pupil size in response to 9 s of exponentially increasing blue (469 nm) and red (640 nm) light-stimuli were assessed monocularly using a custom-built handheld pupillometer. Pupillometric features were extracted from individual traces and compared between groups. Features with the highest classification potential, selected using a gradient boosting machine technique, were incorporated into a generalised linear model for glaucoma classification. Receiver operating characteristic curve analyses (ROC) were used to compare the performance of HCP, optical coherence tomography (OCT) and Humphrey Visual Field (HVF).

RESULTS

Pupillary light responses were altered in glaucoma compared with controls. For glaucoma classification, HCP yielded an area under the ROC curve (AUC) of 0.94 (95% CI 0.91 to 0.96), a sensitivity of 87.9% and specificity of 88.4%. The classification performance of HCP in early-moderate glaucoma (visual field mean deviation (VFMD) > -12 dB; AUC=0.91 (95% CI 0.87 to 0.95)) was similar to HVF (AUC=0.91) and reduced compared with OCT (AUC=0.97; p=0.01). For severe glaucoma (VFMD ≤ -12 dB), HCP had an excellent classification performance (AUC=0.98, 95% CI 0.97 to 1) that was similar to HVF and OCT.

CONCLUSION

HCP allows for an accurate, objective and rapid detection of functional loss in glaucomatous eyes of different severities.

Comparison of Structural, Functional, Tonometric, and Visual Acuity Testing for Glaucoma: A Prospective Diagnostic Accuracy Study

PURPOSE

To determine the diagnostic accuracy of potential screening tests for moderate to advanced glaucoma.

DESIGN

Prospective diagnostic test accuracy study.

PARTICIPANTS

The study enrolled a consecutive series of patients aged ≥50 years who presented to a glaucoma clinic in South India without ever having received automated visual field testing.

METHODS

All participants underwent 8 index tests: OCT of the peripapillary retinal nerve fiber layer, optic disc photography, Moorfield's Motion Displacement Test (MDT), frequency doubling technique perimetry, noncontact tonometry, pneumatonometry, presenting visual acuity, and best-corrected visual acuity. Participants also underwent stereoscopic photographs and Humphrey visual fields, which were used by 2 ophthalmologists to arrive at the reference standard diagnosis of moderate to advanced glaucoma.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio.

RESULTS

A total of 217 people were enrolled; 321 eyes from 180 participants had all tests performed. Of these, 127 eyes (40%) were classified as having moderate to advanced glaucoma. Among the 8 tests, OCT best optimized sensitivity (84%, 95% confidence interval [CI], 76-90) and specificity (75%, 95% CI, 68-81). Moorfield's Motion Displacement Test was the best perimetric test, with a sensitivity of 91% (95% CI, 85-96) and specificity of 53% (95% CI, 44-61). Pressure and vision tests were not sensitive (e.g., sensitivity of 16%, 95% CI, 9-23 for noncontact tonometry and 23%, 95% CI, 15-31 for best-corrected visual acuity). Moorfield's Motion Displacement Test identified 16 of 127 eyes (13%) with glaucoma that were not captured by OCT, but also had false-positive results in 65 of 194 eyes (34%) without glaucoma that OCT correctly classified as negative.

CONCLUSIONS

OCT had moderate sensitivity and fair specificity for diagnosing moderate to advanced glaucoma and should be prioritized during an initial assessment for glaucoma.

Prevalence of primary open angle glaucoma in the last 20 years: a meta-analysis and systematic review

Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness in the world and is influenced by various sociodemographic factors. This meta-analysis aims to determine the worldwide prevalence of POAG in the adult general population for the last 20 years, and explore variation in prevalence by age, gender and geographical location. An electronic literature search was performed using the PubMed, Embase, and Web of Science databases. Population-based cross-sectional or cohort studies published in the last 20 years (2000–2020) that reported prevalence of POAG were recruited. Relevant studies meeting defined eligibility criteria were selected and reviewed systematically by meta-analysis. The prevalence of POAG was analyzed according to various risk factors. A random effect model was used for the meta-analysis. Fifty publications with a total of 198,259 subjects were included in this meta-analysis. The worldwide overall prevalence of POAG was 2.4% (95% CI 2.0 ~ 2.8%). The prevalence increases with age. Men are found to be more susceptible to POAG than women (RR 1.28, p < 0.01). Africa is found to have the highest prevalence of POAG (4.0%) among all continents. The current estimated global population of POAG is 68.56 million (95% CI 59.99 ~ 79.98). POAG is a worldwide vision threatening disease with high prevalence for the last 20 years. The population-based prevalence of POAG varies widely across individual studies, due to variations in risk factors of age, gender, and population geographic location.

The Global Extent of Undetected Glaucoma in Adults: A Systematic Review and Meta-analysis

TOPIC

Glaucoma is the leading cause of irreversible blindness, despite having good prognosis with early treatment. We evaluated the global extent of undetected glaucoma and the factors associated with it in this systematic review and meta-analysis.

CLINICAL RELEVANCE

Undetected glaucoma increases the risk of vision impairment, which leads to detrimental effects on the quality-of-life and socioeconomic well-being of those affected. Detailed information on the extent and factors associated with undetected glaucoma aid in the development of public health interventions.

METHODS

We conducted a systematic review and meta-analysis of population-based studies published between January 1, 1990, and June 1, 2020. Article search was conducted in online databases (PubMED, Web-of-Science), grey literatures (OpenGrey), and nongovernment organization reports. Our outcome measure was the proportion of glaucoma cases that were undetected previously. Manifest glaucoma included any form of glaucoma reported in the original studies and may include primary open-angle glaucoma (POAG), primary angle-closure-glaucoma, secondary glaucoma, or a combination thereof. Undetected glaucoma was defined as glaucoma cases that were undetected prior to diagnosis in the respective study. Random-effect meta-analysis was used to estimate the pooled proportion of undetected glaucoma. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Meta-analysis of Observational Studies in Epidemiology guidelines in our study.

RESULTS

We identified 61 articles from 55 population-based studies (n = 189 359 participants; n = 6949 manifest glaucoma). Globally, more than half of all glaucoma cases were undetected previously on average in each geographical region. Africa (odds ratio [OR], 12.70; 95% confidence interval [CI], 4.91-32.86) and Asia (OR, 3.41; 95% CI, 1.63-7.16) showed higher odds of undetected glaucoma as compared with Europe. Countries with low Human Development Index (HDI; <0.55) showed a higher proportion of undetected manifest glaucoma as compared with countries of medium to very high HDI (≥0.55; all P < 0.001). In 2020, 43.78 million POAG cases were projected to be undetected, of which 76.7% were in Africa and Asia.

DISCUSSION

Undetected glaucoma is highly prevalent across diverse communities worldwide and more common in Africa and Asia. Strategies to improve detection are needed to prevent excess visual disability and blindness resulting from glaucoma.

Prevalence of glaucoma in the Lao People's Democratic Republic: the Vientiane Eye Study

AIMS

To determine the prevalence and subtypes of glaucoma in Vientiane Province.

METHODS

We conducted a population-based study of 1264 participants aged ≥40 years of age from urban and rural areas of Vientiane Province. Data collection included Snellen visual acuity, slip lamp examination, tonometry, gonioscopy, dilated stereoscopic disc examination and perimetry. Glaucoma was categorised by clinical subtype.

RESULTS

The mean age of the 1264 participants was 57.6 years; 91.9% of eyes had a gradable disc. The prevalence of glaucoma of any category in at least one eye was 1.54% (95% CI 0.66% to 3.59%). The overall prevalence of primary open-angle glaucoma, primary angle-closure glaucoma and secondary glaucoma was 0.62% (95% CI 0.19% to 1.98%), 0.55% (95% CI 0.12% to 2.54%) and 0.37% (95% CI 0.07% to 1.86%); 12 (66.7%) of participants with glaucoma were at least unilaterally blinded by WHO definition.

CONCLUSIONS

The prevalence of glaucoma in the Vientiane Eye Study is relatively low compared with the prevalence reported in other studies from Asian regions; however, the median age in this study was low, reflecting the age group of the population and the rapid urbanisation occurring in the Lao People's Democratic Republic. Nevertheless, glaucoma remains a blinding disease in this population.

Prevalence of Primary Angle Closure Glaucoma in the Last 20 Years: A Meta-Analysis and Systematic Review

Purpose: This meta-analysis aims to investigate the worldwide prevalence of primary angle-closure glaucoma (PACG) and its risk factors in the last 20 years.

Methods: We conducted a systematic review and meta-analysis of 37 population-based studies and 144,354 subjects. PubMed, Embase, and Web of Science databases were searched for cross-sectional or cohort studies published in the last 20 years (2000–2020) that reported the prevalence of PACG. The prevalence of PACG was analyzed according to various risk factors. A random-effects model was used for the meta-analysis.

Results: The global pooled prevalence of PACG was 0.6% [95% confidence interval (CI) = 0.5–0.8%] for the last 20 years. The prevalence of PACG increases with age. Men are found less likely to have PACG than women (risk ratio = 0.71, 95% CI = 0.53–0.93, p < 0.01). Asia is found to have the highest prevalence of PACG (0.7%, 95% CI = 0.6–1.0%). The current estimated population with PACG is 17.14 million (95% CI = 14.28–22.85) for people older than 40 years old worldwide, with 12.30 million (95% CI = 10.54–17.57) in Asia. It is estimated that by 2050, the global population with PACG will be 26.26 million, with 18.47 million in Asia.

Conclusion: PACG affects more than 17 million people worldwide, especially leading a huge burden to Asia. The prevalence of PACG varies widely across different ages, sex, and population geographic variation. Asian, female sex, and age are risk factors of PACG.

Cluster-randomised trial of community-based screening for eye disease in adults in Nepal: the Village-Integrated Eye Worker Trial II (VIEW II) trial protocol

INTRODUCTION

The majority of blindness worldwide could be prevented or reversed with early diagnosis and treatment, yet identifying at-risk and prevalent cases of eye disease and linking them with care remain important obstacles to addressing this burden. Leading causes of blindness like glaucoma, diabetic retinopathy and age-related macular degeneration have detectable early asymptomatic phases and can cause irreversible vision loss. Mass screening for such diseases could reduce visual impairment at the population level.

METHODS AND ANALYSIS

This protocol describes a parallel-group cluster-randomised trial designed to determine whether community-based screening for glaucoma, diabetic retinopathy and age-related macular degeneration reduces population-level visual impairment in Nepal. A door-to-door population census is conducted in all study communities. All adults aged ≥60 years have visual acuity tested at the census visit, and those meeting referral criteria are referred to a local eye care facility for further diagnosis and management. Communities are subsequently randomised to a community-based screening programme or to no additional intervention. The intervention consists of a single round of screening including intraocular pressure and optical coherence tomography assessment of all adults ≥60 years old with enhanced linkage to care for participants meeting referral criteria. Four years after implementation of the intervention, masked outcome assessors conduct a repeat census to collect data on the primary outcome, visual acuity. Individuals with incident visual impairment receive a comprehensive ophthalmological examination to determine the cause of visual impairment. Outcomes are compared by treatment arm according to the originally assigned intervention.

ETHICS AND DISSEMINATION

The trial has received ethical approval from the University of California San Francisco Institutional Review Board, Nepal Netra Jyoti Sangh and the Nepal Health Research Council. Results of this trial will be disseminated through publication in peer-reviewed journals and presentation at local and international meetings.

TRIAL REGISTRATION NUMBER

NCT03752840.

Prevalence of glaucoma in the elderly population in Taiwan: The Shihpai Eye Study

BACKGROUND

This study aimed to evaluate the prevalence, characteristics, and the awareness status of glaucoma in an elderly Chinese population.

METHODS

A total of 460 individuals aged ≥72 years were enrolled in this cross-sectional community-based eye disease screening program. Glaucoma was diagnosed according to the diagnostic criteria proposed by the International Society of Geographical and Epidemiological Ophthalmology. Characteristics of subjects with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) were described and compared between groups using Mann-Whitney U and Fisher's exact tests.

RESULTS

Forty subjects were diagnosed with glaucoma, including 17 subjects with POAG, 22 with PACG, and one with secondary glaucoma. The estimated prevalence of glaucoma, POAG, and PACG was 8.7%, 3.7%, and 4.8%, respectively. In total, 71% of the subjects with PACG and 77% of POAG subjects presented with a normal intraocular pressure (IOP) of <19 mmHg. The demographic and ocular characteristics were similar between the two groups; however, subjects with POAG had a longer axial length and smaller vertical disc diameter than those with PACG. Further, 95% of the glaucoma subjects ever visited the eye clinic, but only 32.5% of them were aware of the disease.

CONCLUSION

Glaucoma is prevalent in the elderly population in Taiwan, but the diagnostic rate and disease awareness are low. Since most subjects with glaucoma presented with normal IOPs, optic disc evaluation is critical for diagnosing glaucoma in the elderly in Taiwan.

Specificity of various cluster criteria used for the detection of glaucomatous visual field abnormalities

Purpose

This study aimed to evaluate the specificity of commonly used cluster criteria for defining the presence of glaucomatous visual field abnormalities and the impact of variations in the criterion used.

Methods

This is an observational study including 607 eyes from 384 healthy participants, and 501 eyes of 345 participants with glaucoma, with at least two reliable 24–2 visual field tests. An abnormal visual field cluster was defined as the presence of ≥3 contiguous abnormal locations. Variations in this definition were evaluated and included (1) whether abnormalities were based on total deviation and/or pattern deviation values; (2) probability cut-off for defining an abnormal location; and (3) whether abnormalities were required to be repeatable (within the same hemifield or at the same locations) or not. These definitions were also compared against pattern standard deviation (PSD) values.

Results

False-positive rates of various cluster criteria ranged between 9% and 46% depending on the specific definitions used. Only definitions that required abnormalities to be repeatable at the same location achieved a false-positive rate of ≤6%. The various cluster criteria generally performed similarly or worse at detecting glaucoma eyes compared with the PSD values.

Conclusions

Commonly used visual field cluster criteria have high false-positive rates that vary widely depending on the definition used. These findings highlight the need to carefully consider the criteria used when designing and interpreting glaucoma clinical studies.

Trial registration number

NCT00221923.

Characteristics of Primary Glaucoma in Eye Clinic of RA Basoeni Hospital, Mojokerto, Indonesia

Glaucoma is the third cause of blindness after cataracts and refractive disorders. About 4.5 million people worldwide suffer from blindness due to primary glaucoma. A study on the characteristics of primary glaucoma in Eye Clinic at RA Basoeni Mojokerto Hospital in the period of January-December 2016 had been performed in a descriptive cross sectional retropective study, observing: glaucoma type, gender, age, laterality, visual acuity, and intra ocular pressure (IOP). The type of primary glaucoma that most patients experienced was primary closed angle glaucoma. In primary open-angle glaucoma, the number of male patients was almost the same as female patients. Whereas, in primary closed-angle glaucoma, there were more female patients than male. Primary glaucoma patients, both open and closed, were mostly >60 years old. Both primary open and closed angle glaucoma occurred mostly bilaterally. The highest visual acuity of primary glaucoma patients was mild vision loss and near-total vision loss. More glaucoma patients had IOP >21 mmHg, both in right and left eye.

Prevalence of glaucoma in Germany: results from the Gutenberg Health Study

PURPOSE

To determine the prevalence of glaucoma according to the International Society for Geographical and Epidemiological Ophthalmology (ISGEO) classification in an adult German cohort.

METHODS

The Gutenberg Health Study is a population-based, prospective cohort study in the Rhine-Main Region in mid-western Germany with a total of 15,010 participants. In this study, the first 5000 subjects with an age range between 35 and 74 years were included. Optic disk pictures were obtained by a non-mydriatic fundus camera (Visucam™) and analyzed using the Visupac™ software. Glaucoma prevalence was determined in two steps. First, the ISGEO classification was applied using "hypernormal subjects" (normal visual field) as reference. In the second analysis, we additionally considered the disk area (DA) in relation to the vertical cup-to-disk ratio by quantile regression. All results are given as weighted numbers for the population of Mainz/Bingen.

RESULTS

The prevalence of definite glaucoma in our sample was 1.44% (n = 72). The prevalence adjusted for disk area was 1.34% (n = 67). The prevalence gradually increased in both models with each decade of age (from 0.9 to 2.4%, respectively). In both models, none of the glaucoma cases had a small optic disk (< 1.6 mm²). Glaucoma prevalence in medium optic disks was 1.0% (without DA adjustment) vs. 1.6% (with DA adjustment) and in large optic disks 5.6 vs. 2.5%.

CONCLUSIONS

The prevalence of definite glaucoma was similar to other European population-based cohorts, with slightly higher prevalence in younger subjects. Our analysis highlighted the influence of optic disk size in determining the diagnosis of glaucoma based on cup-to-disk ratio in epidemiological studies.

Performance of an iPad Application to Detect Moderate and Advanced Visual Field Loss in Nepal

PURPOSE

To evaluate the accuracy and efficiency of Visual Fields Easy (VFE), a free iPad app, for performing suprathreshold perimetric screening.

DESIGN

Prospective, cross-sectional validation study.

METHODS

We performed screening visual fields using a calibrated iPad 2 with the VFE application on 206 subjects (411 eyes): 210 normal (NL), 183 glaucoma (GL), and 18 diabetic retinopathy (DR) at Tilganga Institute of Ophthalmology, Kathmandu, Nepal. We correlated the results with a Humphrey Field Analyzer using 24-2 SITA Standard tests on 373 of these eyes (198 NL, 160 GL, 15 DR).

RESULTS

The number of missed locations on the VFE correlated with mean deviation (MD, r = 0.79), pattern standard deviation (PSD, r = 0.60), and number of locations that were worse than the 95% confidence limits for total deviation (r = 0.51) and pattern deviation (r = 0.68) using SITA Standard. iPad suprathreshold perimetry was able to detect most visual field deficits with moderate (MD of -6 to -12 dB) and advanced (MD worse than -12 dB) loss, but had greater difficulty in detecting early (MD better than -6 dB) loss, primarily owing to an elevated false-positive response rate. The average time to perform the Visual Fields Easy test was 3 minutes, 18 seconds (standard deviation = 16.88 seconds).

DISCUSSION

The Visual Fields Easy test procedure is a portable, fast, effective procedure for detecting moderate and advanced visual field loss. Improvements are currently underway to monitor eye and head tracking during testing, reduce testing time, improve performance, and eliminate the need to touch the video screen surface.

Glaucoma Screening in Nepal: Cup-to-Disc Estimate With Standard Mydriatic Fundus Camera Compared to Portable Nonmydriatic Camera

PURPOSE

To compare cup-to-disc ratio (CDR) measurements from images taken with a portable, 45-degree nonmydriatic fundus camera to images from a traditional tabletop mydriatic fundus camera.

DESIGN

Prospective, cross-sectional, comparative instrument validation study.

METHODS

Setting: Clinic-based.

STUDY POPULATION

A total of 422 eyes of 211 subjects were recruited from the Tilganga Institute of Ophthalmology (Kathmandu, Nepal). Two masked readers measured CDR and noted possible evidence of glaucoma (CDR ≥ 0.7 or the presence of a notch or disc hemorrhage) from fundus photographs taken with a nonmydriatic portable camera and a mydriatic standard camera. Each image was graded twice.

MAIN OUTCOME MEASURES

Effect of camera modality on CDR measurement; inter- and intraobserver agreement for each camera for the diagnosis of glaucoma.

RESULTS

A total of 196 eyes (46.5%) were diagnosed with glaucoma by chart review; 41.2%-59.0% of eyes were remotely diagnosed with glaucoma over grader, repeat measurement, and camera modality. There was no significant difference in CDR measurement between cameras after adjusting for grader and measurement order (estimate = 0.004, 95% confidence interval [CI], 0.003-0.011, P = .24). There was moderate interobserver reliability for the diagnosis of glaucoma (Pictor: κ = 0.54, CI, 0.46-0.61; Topcon: κ = 0.63, CI, 0.55-0.70) and moderate intraobserver agreement upon repeat grading (Pictor: κ = 0.63 and 0.64, for graders 1 and 2, respectively; Topcon: κ = 0.72 and 0.80, for graders 1 and 2, respectively).

CONCLUSIONS

A portable, nonmydriatic, fundus camera can facilitate remote evaluation of disc images on par with standard mydriatic fundus photography.

Update on the Prevalence, Etiology, Diagnosis, and Monitoring of Normal-Tension Glaucoma

Glaucoma is a leading cause of blindness worldwide. Normal-tension glaucoma (NTG) is a type of open-angle glaucoma with intraocular pressure measurements always 21 mm Hg or less. A controversy surrounding NTG is the question of whether it should be regarded as a disease within the spectrum of primary open-angle glaucoma or as a distinctive disease entity. Nonetheless, NTG does have distinctive features compared with primary open-angle glaucoma: intraocular pressure-independent risk factors for development of NTG, characteristic patterns of structural and functional damage, and a unique disease course. This review provides an overview and update on the current issues surrounding the prevalence, etiology, diagnosis, and monitoring of NTG.

A Population-based survey of the prevalence and types of glaucoma in Nigeria: results from the Nigeria National Blindness and Visual Impairment Survey

Background

Glaucoma is the leading cause of irreversible blindness worldwide. There tends to be a lower reporting of glaucoma in Africa compared to other blinding conditions in global burden data. Research findings of glaucoma in Nigeria will significantly increase our understanding of glaucoma in Nigeria, in people of the West African diaspora and similar population groups. We determined the prevalence and types of glaucoma in Nigeria from the Nigeria National Blindness and Visual Impairment cross-sectional Survey of adults aged ≥40 years.

Methods

Multistage stratified cluster random sampling with probability-proportional-to-size procedures were used to select a nationally representative sample of 15,027 persons aged ≥40 years. Participants had logMAR visual acuity measurement, FDT visual function testing, autorefraction, A-scan biometry and optic disc assessment. Participants with visual acuity of worse than 6/12 or suspicious optic discs had detailed examination including Goldmann applanation tonometry, gonioscopy and fundus photography. Disc images were graded by Moorfields Eye Hospital Reading Centre. Glaucoma was defined using International Society of Geographical and Epidemiological Ophthalmology criteria; and classified into primary open-angle or primary angle-closure or secondary glaucoma. Diagnosis of glaucoma was based on ISGEO classification. The type of glaucoma was determined by gonioscopy.

Results

A total of 13,591 participants in 305 clusters were examined (response rate 90.4 %). Optic disc grading was available for 25,289 (93 %) eyes of 13,081 (96 %) participants. There were 682 participants with glaucoma; a prevalence of 5.02 % (95 % CI 4.60–5.47). Among those with definite primary glaucoma that had gonioscopy (n = 243), open-angle glaucoma was more common (86 %) than angle-closure glaucoma (14 %). 8 % of glaucoma was secondary with the commonest causes being couching (38 %), trauma (21 %) and uveitis (19 %). Only 5.6 % (38/682) of participants with glaucoma knew they had the condition. One in every 5 persons with glaucoma (136;20 %) was blind i.e., visual acuity worse than 3/60.

Conclusion

Nigeria has a high prevalence of glaucoma which is largely open-angle glaucoma. A high proportion of those affected are blind. Secondary glaucoma was mostly as a consequence of procedures for cataract. Public health control strategies and high quality glaucoma care service will be required to reduce morbidity and blindness from glaucoma.

Understanding and living with glaucoma and non-communicable diseases like hypertension and diabetes in the Jhaukhel-Duwakot Health Demographic Surveillance Site: a qualitative study from Nepal

Background

Primary open-angle glaucoma (POAG) is one of the most common causes of irreversible blindness. A possible association between POAG and non-communicable diseases such as hypertension and diabetes suggests that the incidence of POAG may increase. People with POAG in Nepal usually present late to hospital and have poor knowledge of glaucoma.

Objectives

Anticipating a knowledge gap regarding these diseases, this study aimed to explore the knowledge of POAG, hypertension, and diabetes in the community and barriers to health care.

Design

We conducted this qualitative study in the Jhaukhel-Duwakot Health Demographic Surveillance Site (JD-HDSS), a peri-urban community near Kathmandu, a capital city of Nepal. To study how disease influences knowledge, we conducted focus group discussions separately for men and women with and without pre-existing POAG, hypertension, and diabetes. Data were analyzed using the framework analysis approach.

Results

Although people suffering from POAG, hypertension, and/or diabetes exhibited adequate knowledge of hypertension and diabetes, they lacked in-depth knowledge of POAG. People believed mostly in internal health locus of control. Perception of disease consequences and impact of disease on daily life was influenced by pre-existing POAG, hypertension, and/or diabetes but only in men. Gender disparity was observed regarding health literacy, health perception, and health barriers, which put women in a more difficult situation to tackle their health. We also revealed a gap between knowledge, attitude, and practice of health among women and healthy men.

Conclusion

Although people in JD-HDSS exhibited adequate knowledge regarding hypertension and diabetes, they lacked in-depth knowledge about POAG. This study demonstrated gender difference in health literacy and access to health care, making women more vulnerable towards disease. We also demonstrated a gap between knowledge, attitude, and practice of health. However, tailored health literacy programs may bring changes in the health status in the community.

Retinal nerve fiber layer thickness in glaucomatous Nepalese eyes and its relation with visual field sensitivity

BACKGROUND

To evaluate peripapillary retinal nerve fiber layer (RNFL) thickness in glaucomatous Nepalese eyes using spectral domain optical coherence tomography (SD-OCT) and study its relationship with visual field sensitivity.

METHODS

A total of 120 eyes comprising primary open angle glaucoma (POAG), glaucoma suspects (GS), normal tension glaucoma (NTG) and healthy subjects (n=30 cases in each group) underwent a complete ophthalmic examination, including optic nerve head (ONH) evaluation and standard automated perimetry (SAP). RNFL thickness measurements around the optic disk were taken with circular spectral domain optical coherence tomography (SD-OCT) scans. Analysis of variance (ANOVA) was used for comparison of RNFL parameters among various study groups. The relationship of RNFL parameters with visual field (VF) global indices was evaluated with regression analysis.

RESULTS

The mean pRNFL thickness was significantly less in the POAG (64.30±14.45μm, p<0.01), NTG (85.43±9.79μm, p<0.001) and GS (102.0±9.37μm, p<0.001) groups than in the healthy group (109.8±8.32μm). The RNFL was significantly thinner across all quadrants in all study group pairs (p<0.05) except for normal vs. GS (only superior and inferior quadrant, significant). Linear regression plots with RNFL thickness as a predictor of MD and LV demonstrated a strong and statistically significant degree of determination in the POAG group (R(2)=0.203 and 0.175, p=0.013 and 0.021).

CONCLUSION

The RNFL thickness measurements with SD-OCT are lower in glaucomatous eyes as compared to age-matched GS and normal eyes in the Nepalese population. A high resolution SD-OCT could aid significantly in the early diagnosis of glaucoma in Nepal.

The prevalence of primary angle closure glaucoma in adult Asians: a systematic review and meta-analysis

BACKGROUND

Primary angle closure glaucoma (PACG) is higher in Asians than Europeans and Africans, with over 80% of PACG worldwide in Asia. Previous estimates of PACG were based largely on early studies, mostly using inappropriate case definitions. Therefore, we did a systematic review and meta-analysis to estimate the prevalence of PACG in adult Asian populations and to quantify its association with age, gender, and region.

METHODS

All primary reports of population-based studies that reported the prevalence of PACG in adult Asian populations were identified. PACG case definition was compatible with the ISGEO definition. Twenty-nine population-based studies were included. The overall pooled prevalence estimates were calculated using a random effect model, and ethnicity-, age- and gender-specific pooled prevalence estimates were also calculated.

RESULTS

The overall pooled prevalence of PACG in those of adult Asians was 0.75% (95% CI, 0.58, 0.96). Ethnicity-specific pooled prevalence estimates were 0.97% (0.22, 4.27) in Middle East group, 0.66% (0.23, 1.86) in South East Asia group, 0.46% (0.32, 0.64) in India group, 1.10% (0.85, 1.44) in China group, and 1.19% (0.35, 3.98) in Japan group, respectively. Age-specific prevalence was 0.21% (0.12, 0.37) for those 40-49 years, 0.54% (0.34, 0.85) for those 50-59 years, 1.26% (0.93, 1.71) for those 60-69 years, and 2.32% (1.74, 3.08) for those 70 years or above. The overall female to male ratio of the PACG prevalence was 1.51∶1 (95% CI 1.01, 2.28).

CONCLUSIONS

PACG affects approximately 0.75% adult Asians, increasing double per decade, and 60% of cases being female. The prevalence rates vary greatly by ethnic region.

Global prevalence of glaucoma and projections of glaucoma burden through 2040: a systematic review and meta-analysis

PURPOSE

Glaucoma is the leading cause of global irreversible blindness. Present estimates of global glaucoma prevalence are not up-to-date and focused mainly on European ancestry populations. We systematically examined the global prevalence of primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG), and projected the number of affected people in 2020 and 2040.

DESIGN

Systematic review and meta-analysis.

PARTICIPANTS

Data from 50 population-based studies (3770 POAG cases among 140,496 examined individuals and 786 PACG cases among 112 398 examined individuals).

METHODS

We searched PubMed, Medline, and Web of Science for population-based studies of glaucoma prevalence published up to March 25, 2013. Hierarchical Bayesian approach was used to estimate the pooled glaucoma prevalence of the population aged 40-80 years along with 95% credible intervals (CrIs). Projections of glaucoma were estimated based on the United Nations World Population Prospects. Bayesian meta-regression models were performed to assess the association between the prevalence of POAG and the relevant factors.

MAIN OUTCOME MEASURES

Prevalence and projection numbers of glaucoma cases.

RESULTS

The global prevalence of glaucoma for population aged 40-80 years is 3.54% (95% CrI, 2.09-5.82). The prevalence of POAG is highest in Africa (4.20%; 95% CrI, 2.08-7.35), and the prevalence of PACG is highest in Asia (1.09%; 95% CrI, 0.43-2.32). In 2013, the number of people (aged 40-80 years) with glaucoma worldwide was estimated to be 64.3 million, increasing to 76.0 million in 2020 and 111.8 million in 2040. In the Bayesian meta-regression model, men were more likely to have POAG than women (odds ratio [OR], 1.36; 95% CrI, 1.23-1.52), and after adjusting for age, gender, habitation type, response rate, and year of study, people of African ancestry were more likely to have POAG than people of European ancestry (OR, 2.80; 95% CrI, 1.83-4.06), and people living in urban areas were more likely to have POAG than those in rural areas (OR, 1.58; 95% CrI, 1.19-2.04).

CONCLUSIONS

The number of people with glaucoma worldwide will increase to 111.8 million in 2040, disproportionally affecting people residing in Asia and Africa. These estimates are important in guiding the designs of glaucoma screening, treatment, and related public health strategies.

Primary open-angle glaucoma in a population associated with high prevalence of primary angle-closure glaucoma: the Kumejima Study

PURPOSE

To evaluate the prevalence of and risk factors for primary open-angle glaucoma (POAG) in a rural population of southwestern Japan.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

All residents 40 years of age and older in Kumejima, Okinawa, Japan.

METHODS

Of the eligible 4632 residents 40 years of age and older, 3762 subjects (participant rate, 81.2%) underwent screening examinations, including visual acuity (VA) measurement, slit-lamp examination, Goldmann applanation tonometry, gonioscopy, undilated stereoscopic fundus photographs, autorefractometry, noncontact specular microscopy, pachymetry, and visual field (VF) testing using frequency-doubling technology. If glaucoma or other related ocular disorders were suspected, subjects were referred for definitive examinations including VF testing with the Humphrey Field Analyzer. The diagnosis of POAG was based on the criteria of the International Society for Geographical and Epidemiological Ophthalmology.

MAIN OUTCOME MEASURES

Prevalence and risk factors of POAG.

RESULTS

The prevalence of POAG was 4.0% (95% confidence interval [CI], 3.4%-4.7%); 82% of patients had an intraocular pressure (IOP) less than 22 mmHg, resulting in a prevalence of 3.3% (95% CI, 2.8%-3.9%). Because of POAG, 3 subjects had a VA worse than 20/400 in only 1 eye, and 1 subject had VA loss of worse than 20/400 bilaterally. The average IOP values (mean ± standard deviation) were 14.9 ± 3.2 and 14.6 ± 3.3 mmHg in the right and left eyes, respectively; the IOP values were higher in patients with POAG (15.4 ± 3.3 and 15.2 ± 3.3 mmHg, respectively) than in subjects without glaucoma (14.8 ± 3.1 and 14.4 ± 3.1 mmHg, respectively; P<0.045, Student t test). Multivariate analysis showed that male gender (P = 0.003), older age (P<0.001), higher IOP (P<0.001), longer axial length (P<0.001), and thinner central cornea (P = 0.006) were associated with POAG.

CONCLUSIONS

High prevalence rates of POAG (4.0%) and POAG with normal IOP levels (3.3%), which were comparable with those on the Japanese mainland, were found in a southwestern rural island of Japan, where the prevalence of primary angle-closure glaucoma (previously reported as 2.2%) was considerably higher than on the Japanese mainland (0.6% in the Tajimi Study) or other countries. The risk factors for POAG included male gender, older age, higher IOP, myopia, and a thinner cornea.

Do non-communicable diseases such as hypertension and diabetes associate with primary open-angle glaucoma? Insights from a case-control study in Nepal

BACKGROUND

Non-communicable diseases (NCDs) such as hypertension and diabetes are rapidly emerging public health problems worldwide, and they associate with primary open-angle glaucoma (POAG). POAG is the most common cause of irreversible blindness. The most effective ways to prevent glaucoma blindness involve identifying high-risk populations and conducting routine screening for early case detection. This study investigated whether POAG associates with hypertension and diabetes in a Nepalese population.

METHODS

To explore the history of systemic illness, our hospital-based case-control study used non-random consecutive sampling in the general eye clinics in three hospitals across Nepal to enroll patients newly diagnosed with POAG and controls without POAG. The study protocol included history taking, ocular examination, and interviews with 173 POAG cases and 510 controls. Data analysis comprised descriptive and inferential statistics. Descriptive statistics computed the percentage, mean, and standard deviation (SD); inferential statistics used McNemar's test to measure associations between diseases.

RESULTS

POAG affected males more frequently than females. The odds of members of the Gurung ethnic group having POAG were 2.05 times higher than for other ethnic groups. Hypertension and diabetes were strongly associated with POAG. The overall odds of POAG increased 2.72-fold among hypertensive and 3.50-fold among diabetic patients.

CONCLUSION

POAG associates significantly with hypertension and diabetes in Nepal. Thus, periodic glaucoma screening for hypertension and diabetes patients in addition to opportunistic screening at eye clinics may aid in detecting more POAG cases at an early stage and hence in reducing avoidable blindness.

Glaucoma screening: current perspectives and future directions

INTRODUCTION

Glaucoma is an optic neuropathy with characteristic progressive optic nerve degeneration. Early detection and treatment may prevent blindness; however, the value of glaucoma screening has been debated.

METHODS

Articles pertaining to glaucoma screening were reviewed.

RESULTS

In reviewing the glaucoma literature, there is a lack of a sensitive and specific screening test and concerns over cost-effectiveness. Methods of screening include population-based screening and opportunistic case finding, which both have advantages and disadvantages.

CONCLUSIONS

Additional research is needed to better understand glaucoma progression as well as to identify improved screening tests. Consideration must be given not only to the feasibility of performing a glaucoma screening, but also to the follow-up and long-term care for glaucoma patients.

Association of genetic variants with primary angle closure glaucoma in two different populations

PURPOSE

A recent large genome-wide association study (GWAS) identified multiple variants associated with primary angle-closure glaucoma (PACG). The present study investigated the role of these variants in two cohorts with PACG recruited from Australia and Nepal.

METHOD

Patients with PACG and appropriate controls were recruited from eye clinics in Australia (n = 232 cases and n = 288 controls) and Nepal (n = 106 cases and 204 controls). Single nucleotide polymorphisms (SNPs) rs3753841 (COL11A1), rs1015213 (located between PCMTD1 and ST18), rs11024102 (PLEKHA7), and rs3788317 (TXNRD2) were selected and genotyped on the Sequenom. Analyses were conducted using PLINK and METAL.

RESULTS

After adjustment for age and sex, SNP rs3753841 was found to be significantly associated with PACG in the Australian cohort (p = 0.017; OR = 1.34). SNPs rs1015213 (p = 0.014; OR 2.35) and rs11024102 (p = 0.039; OR 1.43) were significantly associated with the disease development in the Nepalese cohort. None of these SNPs survived Bonferroni correction (p = 0.05/4 = 0.013). However, in the combined analysis, of both cohorts, rs3753841 and rs1015213 showed significant association with p-values of 0.009 and 0.004, respectively both surviving Bonferroni correction. SNP rs11024102 showed suggestive association with PACG (p-value 0.035) and no association was found with rs3788317.

CONCLUSION

The present results support the initial GWAS findings, and confirm the SNP's contribution to PACG. This is the first study to investigate these loci in both Australian Caucasian and Nepalese populations.

Glaucoma severity and medication adherence in a county hospital population

OBJECTIVE

To assess the association between disease severity and adherence with glaucoma medications in a county hospital population.

DESIGN

Cross-sectional study.

PARTICIPANTS

A total of 126 patients diagnosed with glaucoma receiving intraocular pressure (IOP)-lowering medication were recruited from the San Francisco General Hospital Ophthalmology Clinic.

METHODS

Subjects completed an oral questionnaire to assess demographic information, knowledge of glaucoma, and perceptions of glaucoma medication adherence. Glaucoma disease severity was classified according to the American Academy of Ophthalmology's Preferred Practice Pattern guidelines. Medication adherence was measured for each patient by obtaining pharmacy refill data and calculating medication possession ratio (MPR), that is, the ratio of total days' supply of medication during a 365-day period. Adherence was measured retrospectively over the 18-month period before study entry. Subjects with an MPR >80% were considered adherent.

MAIN OUTCOME MEASURE

Medication adherence.

RESULTS

Subjects with mild or moderate glaucoma were more likely to be nonadherent to their prescribed glaucoma medications than those with severe disease (adjusted odds ratio [OR], 1.54; 95% confidence interval [CI], 1.03-2.31; P = 0.04). Age, gender, race, education level, years of glaucoma, number of medications, and glaucoma diagnosis were not found to be statistically significantly associated with adherence.

CONCLUSION

Patients with severe glaucoma were more likely to adhere to their topical IOP-lowering medication regimen than those with milder glaucomatous disease.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.