Predictors for incidence of primary open-angle glaucoma in a South Indian population: the Chennai eye disease incidence study

Six-Year Incidence and Risk Factors for Primary Open-Angle Glaucoma and Ocular Hypertension: The Singapore Epidemiology of Eye Diseases Study

OBJECTIVE

To determine the incidence and risk factors for primary open-angle glaucoma (POAG) and ocular hypertension (OHT) in a multiethnic Asian population.

DESIGN

Population-based cohort study.

PARTICIPANTS

The Singapore Epidemiology of Eye Diseases study included 10 033 participants in the baseline examination between 2004 and 2011. Of those, 6762 (response rate = 78.8%) participated in the 6-year follow-up visit between 2011 and 2017.

METHODS

Standardized examination and investigations were performed, including slit lamp biomicroscopy, intraocular pressure (IOP) measurement, pachymetry, gonioscopy, optic disc examination and static automated perimetry. Glaucoma was defined according to a combination of clinical evaluation, ocular imaging (fundus photo, visual field, and OCT) and criteria given by International Society of Geographical and Epidemiological Ophthalmology. OHT was defined on the basis of elevated IOP over the upper limit of normal; i.e., 20.4 mmHg, 21.5 mmHg, and 22.6 mmHg for the Chinese, Indian, and Malay cohort respectively, without glaucomatous optic disc change.

MAIN OUTCOME MEASURES

Incidence of POAG, OHT, and OHT progression.

RESULTS

The overall 6-year age-adjusted incidences of POAG and OHT were 1.31% (95% confidence interval [CI], 1.04-1.62) and 0.47% (95% CI, 0.30-0.70). The rate of progression of baseline OHT to POAG at 6 years was 5.32%. Primary open-angle glaucoma incidence was similar (1.37%) in Chinese and Indians and lower (0.80%) in Malays. Malays had higher incidence (0.79%) of OHT than Indians (0.38%) and Chinese (0.37%). Baseline parameters associated with higher risk of POAG were older age (per decade: odds ratio [OR], 1.90; 95% CI, 1.54-2.35; P < 0.001), higher baseline IOP (per mmHg: OR, 1.20; 95% CI, 1.12-1.29; P < 0.001) and longer axial length (per mm: OR, 1.22; 95% CI, 1.07-1.40, P = 0.004).

CONCLUSION

Six-year incidence of POAG was 1.31% in a multiethnic Asian population. Older age, higher IOP, and longer axial length were associated with higher risk of POAG. These findings can help in future projections and guide public healthcare policy decisions for screening at-risk individuals.

FINANCIAL DISCLOSURE(S)

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

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

BACKGROUND

To report 15-year incidence rate of primary open angle glaucoma (POAG) in the Andhra Pradesh Eye Disease Study (APEDS).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Clinical and demographic profile of patients less than 40 years of age presenting to glaucoma services at a tertiary care eye hospital in South India

Purpose

To study the clinical and demographic profile of patients less than 40 years of age presenting to glaucoma services including the reasons for referral.

Methods

Patients in the age group of 5 to 39 years, visiting the glaucoma clinic, who were either suspected to have glaucoma or who had been newly/previously diagnosed with glaucoma were included in the study. After informed written consent, basic demographic details of the participants including age, gender, education, socioeconomic status, and family history were obtained. A comprehensive ophthalmological evaluation was performed by glaucoma specialists.

Results

The proportion of glaucoma in the study population (n = 384) was found to be 31.25%, and the incidence of glaucoma among new patients was found to be 11.9%. Among all glaucomas (n = 120), 44.2% of patients had secondary glaucomas, 27.5% had primary glaucomas, and 28.3% had congenital glaucomas. Also, 67.3% of all glaucoma patients were males. Newly diagnosed glaucoma patients presented with a mean intraocular pressure (IOP) of 32.9 mmHg and mild-moderate disc damage with a mean cup-disc ratio of 0.65. Nearly one-third of them had a presenting visual acuity worse than 5/60. The most common reason for referral was raised IOP. Univariate and multivariate analysis revealed that the odds of developing glaucoma were less in females (P = 0.04) and in patients with a higher standard of living index (P < 0.001).

Conclusion

One-third of the patients had glaucoma and another one-third were suspects. Secondary glaucomas are more common than primary/congenital glaucomas. A comprehensive eye evaluation is a must, especially in those with predisposing factors.

Study to Identify and Evaluate Predictor Factors for Primary Open-Angle Glaucoma in Tertiary Prophylactic Actions

The aim of this study is to develop a predictive model with several explanatory variables that can guide ophthalmologists to make a more objective assessment of the evolution of open-angle glaucoma (OAG) during tertiary prevention. Objectives: The evaluation of risk factors and different predictors of symptom progression between patients with POAG and non-glaucoma patients (NG), as well as between primary open-angle glaucoma with high intraocular pressure (POAG) and primary open-angle glaucoma with normal intraocular pressure (NTG), in tertiary prophylactic activities. Methods: This research is an analytical epidemiological study of a prospective cohort. For the study, we took into account personal medical history, physical ophthalmological examination, intraocular pressure (IOP) values, and visual field (VF) parameters, examined with the Opto AP-300 Automated Perimeter using the “fast threshold” strategy. The results of gonioscopy were inconsistently recorded; they were not considered in the study due to missing values, the processing of which would have seriously distorted the statistical analysis. Ophthalmological examination was completed with a dichotomous questionnaire entitled “Symptom Inventory”, made according to the accusations of patients resulting from a “focus group” study. The study was carried out in the ophthalmology office within the Integrated Outpatient Clinic of the Emergency Clinical Hospital of Oradea, Bihor County (IOCECHO) between January−December 2021. The threshold of statistical significance was defined for p value < 0.05. The obtained results were statistically processed with specialized software SPSS 22. Results: The study included 110 people, of which 71 (64.54%) had POAG (IOP > 21 mmHg) and 39 people (35.46%) had NTG (IOP < 21 mmHg), the two groups being statistically significantly different (χ2 = 9.309, df = 1, p = 0.002). For the POAG group, glaucomatous loss was early, AD < −6 dB, according to the staging of glaucomatous disease, HODAPP classification. In addition, the groups of POAG and NTG patients was compared with a group of 110 NG patients, these three groups being statistically significantly different (χ2 = 34.482, df = 2, p = 0.000). Analysis of confounding factors (age, sex, residence, marital status) shows a statistically significant relationship only for age (F = 2.381, df = 40, p = 0.000). Sex ratio for the study groups = 5.11 for OAG and =5.87 for NG. After treatment (prostaglandin analogues and neuroprotective drugs) IOP decreased statistically significantly for both POAG and NTG. Conclusions: this study identified possible predictors of OAG, at the 5% level (risk factors and symptoms as independent variables) using a dichotomous questionnaire tool with a complementary role in tertiary prophylactic activities. The implementation of the focus group interview results as a socio-human research technique will be supportive to clinicians.

Degree of Myopia and Glaucoma Risk: A Dose-Response Meta-analysis

PURPOSE

To verify the dose-response relation between the degree of myopia and open-angle glaucoma (OAG) risk DESIGN: Dose-response meta-analysis.

METHODS

We searched the PubMed, EMBASE, and Cochrane Library databases for population-based studies published until November 30, 2020, and reporting on both myopia and OAG. Random-effect models generated pooled odds ratios (OR) and 95% CIs. Results robustness was confirmed by influence and subgroup analyses. A 2-stage dose-response meta-analysis calculated the OAG risk per unit dose of myopia (spherical equivalent [SE] decrease of 1 diopter [D]) and examined the relationship pattern.

RESULTS

The meta-analysis comprised 24 studies in 11 countries (514,265 individuals). The pooled OR of any myopia degree's association with OAG was 1.88 (95% CI, 1.66-2.13; I² = 53%). The OR differences based on ethnicity (Asians vs Westerners) or 5 geographic areas were not statistically significant (P = .80 and P = .06, respectively). The pooled ORs of the associations between low, moderate, moderate-to-high, high myopia, and OAG were 1.50 (95% CI, 1.29-1.76), 1.69 (95% CI, 1.33-2.15), 2.27 (95% CI, 1.74-2.96), and 4.14 (95% CI, 2.57-6.69), respectively. According to the dose-response meta-analysis, the pooled OR (per SE 1-D change) was 1.21 (95% CI, 1.15-1.28). The OAG risk accelerated at approximately -6 D, and further accelerated from -8 D, showing a nonlinear concave upward slope (P = .03).

CONCLUSIONS

For each unit (1-D) increase in myopia, the risk of glaucoma increases by approximately 20%. The risk more steeply increases in high-degree myopia, representing a significant nonlinear relationship.

Healthy Lifestyle Score and Incidence of Glaucoma: The Sun Project

Background: The relationship between modifiable risk factors, such as diet and lifestyle, and glaucoma remains controversial. We analyse the effect of the Mediterranean lifestyle (ML) on glaucoma incidence in the “Seguimiento Universidad de Navarra” (SUN) Project. Methods: The SUN Healthy Lifestyle Score (SHLS) includes 10 healthy habits: never having smoked, moderate to high physical activity, Mediterranean diet adherence, moderate alcohol consumption, low television exposure, no binge drinking, short afternoon napping, meeting up with friends, working at least 40 h/wk, and low body mass index. The information was collected biennially through self-reported questionnaires. The relationship between new glaucoma cases and the SHLS was assessed by Cox regression using hazard ratios. Crude, multi-adjusted, and sensitivity analyses were performed. Results: During a median of 12 years of follow-up, 261 (1.42%) new cases of glaucoma were identified among 18,420 participants. After adjusting for potential confounders, participants in the healthiest SHLS category showed a significantly reduced risk of glaucoma compared to those in the lowest SHLS category (adjusted HR = 0.51, 95% CI = 0.28–0.93). For each point added to the SHLS, the risk of glaucoma relatively dropped 5%. Conclusions: Higher adherence to a ML, measured by the SHLS, was significantly associated with a lower risk of developing glaucoma. Based on our study, the ML is a protective factor for glaucoma incidence.

The Association between Myopia and Primary Open-Angle Glaucoma: A Systematic Review and Meta-Analysis

BACKGROUND

Previous studies identified myopia as a risk factor for primary open-angle glaucoma (POAG). However, recent studies have shown different results, the definitive relationship between myopia and POAG remains controversial.

OBJECTIVES

To investigate the relationship between myopia and POAG.

METHODS

Published articles were searched from PubMed, Embase, and Scopus databases between 1970 and 2020. A pooled analysis of the ORs was performed using a random-effects model.

RESULTS

Data on the association between myopia and POAG, were obtained from 16 cross sectional studies, and the pooled OR was 2.26 (95% confidence interval [CI], 1.77 - 2.89, P < 0.001) in random effects model (I2 = 86%; P < 0.01). For the relationship of myopia and POAG progression, data from seven longitudinal cohort studies were included and the pooled OR was 0.85 (95% CI, 0.73 - 0.99, P = 0.042) in the random-effects model (I2 = 88%; P < 0.01).

CONCLUSION

Our findings demonstrated that myopia may be a risk factor associated with POAG and a possible protective factor for POAG progression. It may due to myopia with the presence of a lamina cribrosa defect slow down the visual field loss also POAG progression, further research for underlying mechanisms is still needed.

Clinical Utility of Bruch Membrane Opening-Minimum Rim Width for Detecting Early Glaucoma in Myopic Eyes

PRCIS

Bruch membrane opening-minimum rim width (BMO-MRW) is overall a useful parameter for diagnosing early glaucoma in myopic eyes.

PURPOSE

The aim of this study was to determine the diagnostic value of BMO-MRW compared with peripapillary retinal nerve fiber layer (pRNFL) thickness for detecting early glaucoma in patients with moderate to severe myopia.

METHODS

One eye was randomly selected from each of the 253 subjects (127 normal controls, 82 with glaucoma suspect, and 44 with early glaucoma). All patients underwent visual acuity testing, refractive error assessment, slit-lamp inspection, intraocular pressure measurement, fundus photography, perimetry. BMO-MRW and pRNFL thickness data were obtained using spectral-domain optical coherence tomography. Area under the receiver operating characteristic curves (AUC) for global and sectoral thickness parameters were calculated.

RESULTS

Global analyses for the discrimination of early glaucoma in all myopic subjects showed comparable AUCs between BMO-MRW and pRNFL thickness [AUC 0.952 (95% confidence interval, 0.918-0.975) and 0.934 (95% confidence interval, 0.896-0.961), respectively, P=0.345]. However, in sectoral analysis, BMO-MRW showed significantly better diagnostic performance than pRNFL thickness except for the superotemporal sector. The AUC for discriminating early glaucoma from glaucoma suspect, BMO-MRW showed statistically better diagnostic performance in the inferotemporal, inferonasal, superonasal, and nasal sectors. When dividing the subject based on a threshold Bruch membrane opening (BMO) area of 2.5 mm2, the diagnostic power of BMO-MRW was generally lower except for the inferonasal sector in the subgroup with a large BMO area.

CONCLUSIONS

BMO-MRW was overall a useful parameter for diagnosing early glaucoma in myopic eyes. However, its diagnostic performance was decreased in myopic eyes with large BMO and there were no significant differences from pRNFL thickness.

Association of metformin use among diabetics and the incidence of primary open-angle glaucoma - The Chennai Eye Disease Incidence Study

Purpose

Studies have reported the usage of metformin being associated with the reduced risk of progression of glaucoma. The current study aims to determine the association of metformin usage among subjects with diabetes mellitus and the six-year incidence of primary open-angle glaucoma (POAG).

Methods

In this prospective cohort study, subjects who did not have glaucoma at the baseline and had a follow-up after a six-year interval were included. Details such as medical and drug history, applanation tonometry, gonioscopy, pachymetry, optic disc evaluation, and automated perimetry were collected. Incident POAG was defined as subjects who do not have glaucoma at baseline and developed glaucoma as classified International Society of Geographical and Epidemiological Ophthalmology Classification at the follow-up. The association between the subjects who were on metformin for treatment of diabetes mellitus and development of incident POAG was assessed.

Results

Among the 4302 eligible participants, 128 (3%) had incident POAG. There were 905 (21.0%) subjects who had diabetes mellitus of which 142 (15.7%) were using metformin. Of the subjects with POAG, 92 (71.9%) were nondiabetics and 36 were diabetics (28.1%). Among the diabetics, the incidence of POAG among those on metformin was 5.6% (8 participants) and those not on metformin was 3.6% (28 participants). There was no difference in the incidence of POAG in subjects with diabetes mellitus, with and without metformin use (P = 0.25). Logistic regression showed no association of metformin use with the incidence of POAG (OR: 1.33, 95 CI: 0.58-3.04, P = 0.49) after adjusting for age, gender, and place of residence.

Conclusion

The current study did not find any association between the effects of metformin on the incidence of POAG.

Association Between Diabetes, Diabetic Retinopathy, and Glaucoma

PURPOSE OF REVIEW

The strength of the relationship between diabetes, diabetic retinopathy (DR), and glaucoma remains controversial. We review evidence supporting and refuting this association and explore mechanistic pathological and treatment relationships linking these diseases.

RECENT FINDINGS

While studies have shown diabetes/DR may increase the risk for glaucoma, this remains inconsistently demonstrated. Diabetes/DR may contribute toward glaucomatous optic neuropathy indirectly (either by increasing intraocular pressure or vasculopathy) or through direct damage to the optic nerve. However, certain elements of diabetes may slow glaucoma progression, and diabetic treatment may concurrently be beneficial in glaucoma management. Diabetes plays a significant role in poor outcomes after glaucoma surgery. While the relationship between diabetes/DR and glaucoma remains controversial, multiple mechanistic links connecting pathophysiology and management of diabetes, DR, and glaucoma have been made. However, a deeper understanding of the causes of disease association is needed.

Twelve-Year Incidence of Open-angle Glaucoma: The Thessaloniki Eye Study

OBJECTIVE

The objective of this study was to determine the 12-year incidence of open-angle glaucoma (OAG), with further classification into primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG), in an elderly White population.

DESIGN

A longitudinal, population-based study in urban Northern Greece.

PARTICIPANT

Surviving cohort of the 2554 Thessaloniki Eye Study subjects 60 years and above who had the baseline examination.

METHODS

The surviving cohort was re-examined 12 years after baseline, using the same methodology and the same standard operating procedures as in the baseline examination. The definitions of glaucoma and pseudoexfoliation were consistent throughout the study. The 12-year incidences of OAG, POAG, and PEXG with corresponding 95% confidence intervals (CIs) were calculated for the whole study population, consisting of clinic-visit and home-visit participants. The population at risk was defined as those who did not meet the study criteria for the diagnosis of glaucoma in either eye at baseline.

MAIN OUTCOME MEASURES

Twelve-year incidence of OAG, with further classification into POAG and PEXG.

RESULTS

Of 1468 eligible subjects in the surviving cohort, 1092 were examined (participation rate 74%). Mean age at baseline was 68.9±4.6 years. Mean follow-up time was 11.6±1.6 years. The 12-year incidence of OAG was 4.4% (95% CI: 3.3-5.8); 0.37% per year. In the overall population the incidence of POAG and PEXG was 2.1% (95% CI: 1.3-3.2) and 2.3% (95% CI: 1.5-3.4), respectively. The corresponding incidence proportions were 2.9 (95% CI: 1.8-4.3) in those without PEX and 8.9 (95% CI: 5.8-12.9) in those with PEX at baseline and/or incidence. The latter was strongly associated with higher odds for incident glaucoma (odds ratio=3.34, 95% CI: 1.83-6.08, P<0.001). Of all incident OAG cases, 11.1% (95% CI: 4.4-24) had baseline intraocular pressure >21 mm Hg.

CONCLUSIONS

The incidence of OAG was similar or higher compared with other White populations. The incidence of glaucoma in those with PEX was higher compared with the incidence of glaucoma in those without PEX.

Carbohydrate intake and risk of glaucoma in the sun cohort

PURPOSE

To assess the association between carbohydrates (CH) intake and glaucoma incidence.

METHODS

18,247 volunteer participants (183,067 person-years at risk) with 10-year of median follow-up were included in this prospective dynamic cohort. Baseline total CH intake (g/d) was categorised in quartiles and classified in nine different CH food sources. Self-reported diagnosis of glaucoma was collected at baseline and on biennial follow-up questionnaires. CH intake and glaucoma diagnosis were validated in a subsample of participants. We studied potential confounders and effect modificators, including diabetes. The relationship between CH intake and glaucoma incidence was analysed using multivariable Cox proportional hazards ratio (HR) models to adjust for potential confounding factors.

RESULTS

During 10 years of median follow-up, a total of 242 new cases of glaucoma were identified. Participants in the highest quartile of baseline CH intake had a significantly higher risk of glaucoma as compared to participants in the lowest quartile [HR 1.50 (95% Confidence interval (CI): 1.01-2.25), p for trend = 0.042]. None of the nine CH food groups was individually related to glaucoma. In stratified analyses, after excluding all cases of diabetes, the HR comparing extreme quartiles of CH intake was 1.77 (95% CI: 1.15-2.74).

CONCLUSIONS

Our results suggest that a higher intake of total carbohydrates is associated with a higher risk of incident glaucoma. The total amount of CH, rather than the specific food sources of CH, seems to play a major role, and this association does not seem to be confounded or modified by diabetic status.

Risk factors for open-angle glaucoma and recommendations for glaucoma screening

Open-angle glaucomas are a group of chronic progressive optic nerve neuropathies with a gonioscopic open anterior chamber angle. They are one of the main causes of visual impairment and blindness in industrialized countries. The aim of this article is to discuss and evaluate the epidemiology and risk factors for the development of open-angle glaucoma and to present the screening procedure for open-angle glaucoma according to the recently published S2e guidelines of the Association of the Scientific Medical Societies in Germany (AWMF).

Open-angle glaucoma in a rural and urban population in Eastern India-the Hooghly river glaucoma study

Purpose

Glaucoma is the leading cause of irreversible blindness in the world. The current study aims to estimate prevalence, features, and associations of open angle glaucoma (OAG) in a rural and urban East Indian population.

Methods

This is a population based cross sectional study with two arms, rural (28 contiguous villages from 13 Gram Panchayats in Balagarh Police Station, Hooghly district) and urban (Kolkata). Individuals residing in the study area aged 40 years and above were included using multistage random cluster sampling. All subjects underwent a detailed ophthalmic examination at our base hospitals including applanation tonometry, ultrasound pachymetry, gonioscopy, and frequency doubling technology perimetry. The primary outcome was the prevalence of POAG (95% CI). Age and gender specific prevalence estimates were calculated. Multiple logistic regressions were used to analyze the risk factors.

Results

Data from 7128 and 6964 subjects aged 40 years or older from Kolkata city and Hooghly district, respectively were analyzed. In the urban population, 2.10% (95% CI: 1.99-2.21%) had POAG and 0.15% (95% CI: 0.13-0.17%) had secondary OAG. In the rural population, 1.45% (95% CI: 0.59-2.31%) had POAG and 0.10 ± 0.03% (95% CI: 0.07-0.13%) had secondary OAG.

Conclusion

The study concludes that higher age, higher vertical cup disc ratio (VCDR), and lower central corneal thickness (CCT) are important independent predictors of OAG and emphasizes that increased intraocular pressure (IOP) is not POAG. Gonioscopy, disc evaluation, and screening perimetry need to be incorporated in the detection protocol for glaucoma if we intend to lighten the burden of blindness due to glaucoma.

[Risk factors for open-angle glaucoma and recommendations for glaucoma screening]

Open-angle glaucomas are a group of chronic progressive optic nerve neuropathies with a gonioscopic open anterior chamber angle. They are one of the main causes of visual impairment and blindness in industrialized countries. The aim of this article is to discuss and evaluate the epidemiology and risk factors for the development of open-angle glaucoma and to present the screening procedure for open-angle glaucoma according to the recently published S2e guidelines of the Association of the Scientific Medical Societies in Germany (AWMF).

Six-Year Incidence and Risk Factors of Primary Glaucoma in the Singapore Indian Eye Study

PURPOSE

To determine the 6-year incidence of primary glaucoma and its risk factors in an Indian population in Singapore.

DESIGN

Cohort population-based study.

PARTICIPANTS

Indian adults between 40 and 80 years of age living in Singapore. A total of 3400 participants underwent the baseline examination between 2007 and 2009. Of them, 2200 (response rate, 75.5% of those eligible) participated in the 6-year follow-up visit between 2013 and 2015.

METHODS

Standardized examination and investigations were performed, including indentation gonioscopy, intraocular pressure (IOP) measurement, optic disc examination, and static automated perimetry. Glaucoma was defined according to the International Society Geographical and Epidemiological Ophthalmology criteria.

MAIN OUTCOME MEASURES

Incidences of primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).

RESULTS

The age-standardized incidences of primary glaucoma, POAG, and PACG were 1.68% (95% confidence interval [CI], 1.21%-2.32%), 1.37% (95% CI, 0.94%-1.96%), and 0.32% (95% CI, 0.15%-0.66%), respectively. For eyes with ocular hypertension (n = 45) at baseline, the incidence of POAG was 4.83% (95% CI, 1.24%-17.21%) and for eyes with primary angle closure (n = 14) or suspected primary angle closure (n = 101), the incidence of PACG developing was 1.82% (95% CI, 0.37%-9.68%). Baseline factors associated significantly with risk of primary glaucoma developing included older age (per decade; odds ratio [OR], 1.84; 95% CI, 1.44-2.36; P < 0.001), larger vertical cup-to-disc ratio (per 0.1 unit; OR, 2.78; 95% CI, 2.12-3.64; P < 0.001), and higher IOP (per millimeter of mercury; OR, 1.25; 95% CI, 1.13-1.38; P < 0.001). However, 71 of 85 eyes (84.5%) diagnosed with incident glaucoma had IOP of less than 21 mmHg at the time of examination.

CONCLUSIONS

Our study showed that the overall age-standardized incidence of primary glaucoma was 1.68% in an Indian population in Singapore. In our population, the incidence of POAG was only half and the incidence of PACG was similar to the incidence reported by the Chennai Eye Disease Study.

Retinal Nerve Fiber Layer Thickness Decrease in Obesity as a Marker of Neurodegeneration

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a serious condition that is frequently associated with irreversibly vision loss, having a higher incidence among obese women. Our aims were to screen subclinical IIH in obese patients scheduled to bariatric surgery using peripapillary retinal nerve fiber layer (RNFL) thickness and to evaluate if the findings demand the possible need of a preoperative evaluation in this population.

METHODS

This study included 111 eyes from 36 obese patients (86% female, body mass index > 35 kg/m²) scheduled to bariatric surgery and 20 non-obese (body mass index < 25 kg/m²) age-matched controls. We measured sectorial and mean RNFL thickness in a 3.5-mm-diameter circular scan centered on the optic nerve head, using optical coherence tomography (Heidelberg Spectralis SD-OCT) in all participants. Multivariate linear regression was used for adjustments.

RESULTS

No patient had subclinical IIH corresponding to increased RNFL thickness. However, in obese individuals, global peripapillary RNFL was thinner than in controls (104 ± 6 μm versus 99 ± 12 μm, p = 0.005). Overall, RNFL thickness was superior in the control group for all sectors. The differences reached significance for the nasal, temporal, superior temporal, and inferior temporal sectors. These differences remained even after adjusting for possible confounders (hypertension, dyslipidemia, diabetes, age, sleep apnea syndrome, and sex).

CONCLUSIONS

Routine screening asymptomatic obese patients undergoing bariatric surgery for IIH using RNFL thickness was not clinically relevant in our study. However, we found that severe obesity is associated with neurodegeneration independently of the other components of the metabolic syndrome, what may justify future investigation on the need of monitoring these patients.

Location of Retinal Nerve Fiber Layer Defects in Open-angle Glaucoma and Associated Factors

Purpose

To investigate the location of retinal nerve fiber layer defects (RNFLDs) in open-angle glaucoma and the differences in systemic and ocular factors between superotemporal and inferotemporal RNFLDs.

Methods

We performed a retrospective review of the 2008 to 2012 data from the Korea National Health and Nutrition Examination Survey. Subjects aged ≥19 years with an evaluable fundus photograph of at least one eye were enrolled, and open-angle glaucoma was diagnosed according to modified International Society of Geographical and Epidemiological Ophthalmology criteria. In subjects with open-angle glaucoma, locations of RNFLDs were evaluated, and systemic and ocular factors were compared between the bilateral superotemporal RNFLD group and bilateral inferotemporal RNFLD group.

Results

A total of 534 subjects had open-angle glaucoma with RNFLDs. The unilateral inferotemporal region (25.8%) was the most common location for RNFLDs, followed by the unilateral superotemporal region (24.4%). Multivariate analysis revealed that hypertension was more significantly associated (p = 0.048) with the bilateral superotemporal RNFLD group than with the bilateral inferotemporal RNFLD group.

Conclusions

Superotemporal RNFLDs are more related to hypertension than are inferotemporal RNFLDs.

Prevalence, incidence, and risk factors of primary open-angle glaucoma - a cohort study based on longitudinal data from a German public health insurance

Background

This study estimates the prevalence and incidence rates of primary open -angle glaucoma (POAG) as well as risk factors based on a dataset from the largest German health insurance company.

Methods

A random sample of 250,000 persons at age 50+ of the Allgemeine Ortskrankenkasse (AOK) from 2010 to 2013 was used. Selected risk factors of POAG incidence were analyzed using multivariate Cox proportional hazard models.

Results

The age-standardized prevalence of POAG at age 50+ in 2010 was 2.79% (95%-CI: 2.72–2.85%). The age-standardized total incidence rate was 0.38 (0.36–0.39) per 100 person-years. Sex differences were significant for total prevalence and total incidence rates, with higher prevalence and incidence rates for women compared to men. The Cox model revealed a strong age effect, a significantly 19% higher incidence for women (p ≤ 0.001), injuries of the eye and orbit (175%, p ≤ 0.001), degeneration of iris and ciliary body (155%, p = 0.022), myopia (155%, p ≤ 0.001), retinal vascular occlusions (134%, p ≤ 0.001), hypertension (13%, p ≤ 0.001) and diabetes mellitus (23%, p ≤ 0.001).

Conclusion

Health claims data are an important data source for estimating POAG occurrence and help overcome the problems of small sample sizes. These results may help to understand the causal pathways of POAG and to develop intervention strategies to increase the awareness of patients and physicians with the aim of reducing POAG incidence.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6935-6) contains supplementary material, which is available to authorized users.

Family-Based Genome-Wide Association Study of South Indian Pedigrees Supports WNT7B as a Central Corneal Thickness Locus

Purpose

To identify genetic risk factors contributing to central corneal thickness (CCT) in individuals from South India, a population with a high prevalence of ocular disorders.

Methods

One hundred ninety-five individuals from 15 large South Indian pedigrees were genotyped using the Omni2.5 bead array. Family-based association for CCT was conducted using the score test in MERLIN.

Results

Genome-wide association study (GWAS) identified strongest association for single nucleotide polymorphisms (SNPs) in the first intron of WNT7B and CCT (top SNP rs9330813; β = −0.57, 95% confidence interval [CI]: −0.78 to −0.36; P = 1.7 × 10⁻⁷). We further investigated rs9330813 in a Latino cohort and four independent European cohorts. A meta-analysis of these data sets demonstrated statistically significant association between rs9330813 and CCT (β = −3.94, 95% CI: −5.23 to −2.66; P = 1.7 × 10⁻⁹). WNT7B SNPs located in the same genomic region that includes rs9330813 have previously been associated with CCT in Latinos but with other ocular quantitative traits related to myopia (corneal curvature and axial length) in a Japanese population (rs10453441 and rs200329677). To evaluate the specificity of the observed WNT7B association with CCT in the South Indian families, we completed an ocular phenome-wide association study (PheWAS) for the top WNT7B SNPs using 45 ocular traits measured in these same families including corneal curvature and axial length. The ocular PheWAS results indicate that in the South Indian families WNT7B SNPs are primarily associated with CCT.

Conclusions

The results indicate robust evidence for association between WNT7B SNPs and CCT in South Indian pedigrees, and suggest that WNT7B SNPs can have population-specific effects on ocular quantitative traits.

Eight-Year Incidence of Open-Angle Glaucoma in the Tema Eye Survey

PURPOSE

To determine the incidence of open-angle glaucoma (OAG) and its risk factors in the Tema Eye Survey in Ghana, West Africa.

DESIGN

Longitudinal, observational population-based study.

PARTICIPANTS

One thousand two hundred five of 1500 participants 40 years of age or older selected randomly from 5603 participants originally drawn from the population and who had undergone a baseline examination.

METHODS

All participants underwent baseline and follow-up ophthalmologic examinations 8 years apart. Glaucoma diagnosis was determined based on the International Society for Geographical and Epidemiologic Ophthalmology criteria.

MAIN OUTCOME MEASURES

Incidence and odds ratio (OR).

RESULTS

The response rate was 80.3%. Of 1101 nonglaucomatous participants at baseline who had complete follow-up data, 4.6% (95% confidence interval [CI], 3.7%-5.2%) demonstrated OAG over the 8-year period, or 0.58% (95% CI, 0.4%-0.8%) per year. The 8-year incidence increased with age from 3.1% in those 40 to 49 years old to 7.0% in those 60 to 69 years old. Baseline risk factors for incident OAG were male gender (OR, 2.1; 95% CI, 1.1-4.0; P = 0.025), older age relative to those 40 to 49 years old (those 50-50 years old: OR, 2.6; 95% CI, 1.2-5.7; those 60-69 years old: OR, 4.3; 95% CI, 2.0-8.8; and for those 70 years of age and older: OR, 6.3; 95% CI, 2.6-15.4; all P < 0.001), higher intraocular pressure (IOP; OR, 1.4; 95% CI, 1.1-1.8; P < 0.001), larger vertical cup-to-disc ratio (OR, 5.8; 95% CI, 5.2-6.6; P < 0.001), and thinner central cornea (OR, 1.2; 95% CI, 1.03-1.5; P = 0.013). A separate analysis performed with central corneal thickness-based IOP correction did not change the outcome of the associative model of incident glaucoma.

CONCLUSIONS

The incidence of OAG is higher in this population than reported in nonblack populations outside Africa. This is important not only in Ghana and probably other West African countries but also wherever people of the West African diaspora reside. These data enhance our understanding of the epidemiologic factors of OAG in this setting and may serve as reference for public health policy and planning.

Simplifying "target" intraocular pressure for different stages of primary open-angle glaucoma and primary angle-closure glaucoma

Lowering of intraocular pressure is currently the only therapeutic measure for Glaucoma management. Many longterm, randomized trials have shown the efficacy of lowering IOP, either by a percentage of baseline, or to a specified level. This has lead to the concept of 'Target" IOP, a range of IOP on therapy, that would stabilize the Glaucoma/prevent further visual field loss, without significantly affecting a patient's quality of life. A clinical staging of Glaucoma by optic nerve head evaluation and perimetric parameters, allows a patient's eye to be categorized as having - mild, moderate or severe Glaucomatous damage. An initial attempt should be made to achieve the following IOP range for both POAG or PACG after an iridotomy. In mild glaucoma the initial target IOP range could be kept as 15-17 mmHg, for moderate glaucoma 12-15 mmHg and in the severe stage of glaucomatous damage 10-12 mmHg. Factoring in baseline IOP, age, vascular perfusion parameters, and change on perimetry or imaging during follow up, this range may be reassessed over 6 months to a year. "Target" IOP requires further lowering when the patient continues to progress or develops a systemic disease such as a TIA. Conversely, in the event of a very elderly or sick patient with stable nerve and visual field over time, the target IOP could be raised and medications reduced. An appropriate use of medications/laser/surgery to achieve such a "Target" IOP range in POAG or PACG can maintain visual fields and quality of life, preventing Glaucoma blindness.

Inter-relationship between ocular perfusion pressure, blood pressure, intraocular pressure profiles and primary open-angle glaucoma: the Singapore Epidemiology of Eye Diseases study

Objective

To elucidate the inter-relationship between ocular perfusion pressure (OPP), blood pressure (BP), intraocular pressure (IOP) profiles and primary open-angle glaucoma (POAG) in a multiethnic Asian population.

Methods

Participants were recruited from the Singapore Epidemiology of Eye Diseases Study and underwent standardised ocular and systemic examinations. POAG was defined according to the International Society for Geographical and Epidemiological Ophthalmology criteria. Logistic regression analyses with generalised estimating equation models were performed and used to account for correlation between eyes.

Results

A total of 9877 participants (19 587 eyes), including 213 POAG cases (293 eyes) were included. Eyes with lowest quartile levels of systolic OPP (SOPP <110 mm Hg) were 1.85 times (95% CI 1.16 to 2.95) likely to have POAG, compared with eyes with mid-range SOPP levels (123–137 mm Hg; third quartile), after adjusting for relevant covariates and IOP. Consistently, we found that lowest quartile of systolic BP (SBP <124 mm Hg) was 1.69 times (95% CI 1.08 to 2.66) likely to have POAG, compared with mid-range SBP levels (138–153 mm Hg; third quartile). Furthermore, the effect of lower SBP on POAG was more pronounced in eyes with IOP ≥21 mm Hg (OR 3.90; 95% CI 1.24 to 12.30). Both the mean and diastolic profiles of OPP and BP were not significantly associated with POAG, after adjusting for relevant covariates and IOP.

Conclusions

In this population-based sample of nearly 10 000 Asian individuals, we showed that low SOPP was associated with POAG. This association was potentially in part secondary to low SBP and high IOP. Our findings provide further clarity on the roles of OPP surrogates and BP profiles in POAG.

Diabetes and risk of glaucoma: systematic review and a Meta-analysis of prospective cohort studies

AIM

To quantify the association between diabetes and glaucoma using Meta-analysis.

METHODS

PubMed and Embase were searched using medical subject headings and key words related to diabetes and glaucoma. The inclusion criteria were: 1) the study design was a prospective cohort study; 2) the exposure of interest was diabetes; 3) the outcome of interest was primary open angle glaucoma (POAG); 4) risk ratios (RR) and the corresponding 95% confidence interval (CI). Data were pooled using fixed effects models to take into account heterogeneity between studies. Seven prospective studies were selected. Diabetes increased the incidence of glaucoma by 36% (OR=1.36, 95% CI=1.25-1.50). There was no evidence of statistical heterogeneity (I²=0, P=0.53) or publication bias (the funnel plot did not identify obvious asymmetry).

RESULTS

Seven prospective cohort studies were incorporated in this Meta-analysis. The pooled RR of the association between POAG and diabetes based on the risk estimates of the seven cohort studies was 1.36 (95%CI=1.24-1.50), with no significant heterogeneity across studies (I²=0; P=0.526). The sensitivity analysis yielded a range of RRs from 1.34 (95%CI=1.22-1.48) to1.40 (95%CI=1.18-1.67).

CONCLUSION

Diabetes is associated with a significantly increased risk of glaucoma.

Longitudinal Cohort Study on the Incidence of Primary Open-Angle Glaucoma in Bai Chinese

PURPOSE

The prevalence of primary open-angle glaucoma (POAG) in China has been reported previously, and was lower than that in white and black populations. However, the incidence of POAG in China has not been reported. Therefore, a longitudinal study was conducted to determine the 5-year cumulative incidence and predictors of POAG in China.

DESIGN

Population-based cohort study.

METHODS

A total of 1520 participants (71.3% of the subjects in the baseline survey) of Bai ethnicity were examined and followed for 5 years. Glaucoma was defined based on the International Society of Geographical and Epidemiological Ophthalmology Classification criteria. Multivariable logistic regression models were fitted to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

A total of 19 new cases of POAG were detected. The 5-year cumulative incidence of POAG was 1.3% (95% CI, 0.7-1.9). In multivariate analyses, incident POAG was associated with baseline variables including increased age (OR, 4.3; 95% CI, 1.4-13.8; P = .02; 70 years or older vs 50-59 years), elevated IOP (OR, 3.5; 95% CI, 2.0-5.9; P < .001; per 10 mm Hg increase), lower education level (OR, 0.3; 95% CI, 0.1-0.8; P = .02; post-primary education vs no formal education), and the presence of myopia (OR, 3.4; 95% CI, 1.3-8.6; P < .01).

CONCLUSIONS

The average annual incidence of POAG in Bai Chinese was lower than that in populations of African descent and white race. The results are important to elucidate the racial/ethnic difference in POAG incidence and for the clinical management and health resource allocation in China.

Glaucoma history and risk factors

Apart from the risk of developing glaucoma there is also the risk that it is not detected and irreversible loss of vision ensues. Some studies of methods of glaucoma diagnosis have examined the results of instrument-based examinations with great if not complete reliance on objective findings in arriving at a diagnosis. The very valuable advances in glaucoma detection instrument technologies, and apparent increasing dependence on them, may have led to reduced consideration of information available from a patient history in those studies. Dependence on objective evidence of glaucomatous pathology may reduce the possibility of detecting glaucoma suspects or patients at risk for becoming glaucoma suspects. A valid positive family history of glaucoma is very valuable information. However, negative family histories can often be unreliable due to large numbers of glaucoma cases being undiagnosed. No evidence of family history is appropriate rather than no family history. In addition the unreliability of a negative family history is increased when patients with glaucoma fail to inform their family members. A finding of no family history can only be stated as no known family history. In examining the potential diagnostic contribution from a patient history, this review considers, age, frailty, race, type and degree of refractive error, systemic hyper- and hypotension, vasospasm, migraine, pigmentary dispersion syndrome, pseudoexfoliation syndrome, obstructive sleep apnea syndrome, diabetes, medication interactions and side effects, the degree of exposure to intraocular and intracranial pressure elevations and fluctuations, smoking, and symptoms in addition to genetics and family history of the disease.

Associations between chronic systemic diseases and primary open angle glaucoma: an epidemiological perspective

Glaucoma is a leading cause of global irreversible blindness. Primary open angle glaucoma (POAG) is the most common form of glaucoma and affects 44.1 million individuals worldwide. Elevation of intraocular pressure and impairment of vascular supply to the optic nerve head are two key pathogenic processes in the development of POAG. In this regard, chronic systemic conditions such as hypertension, diabetes and obesity have been postulated to be correlated with these two pathogenic processes. Thus, it is plausible that chronic systemic diseases may act as risk factors for POAG. The aim of this review is to summarize the current evidence on the associations of chronic systemic diseases with POAG. These information will help to further ascertain the risk factors for POAG and improve the early detection of POAG.

Joint Effects of Intraocular Pressure and Myopia on Risk of Primary Open-Angle Glaucoma: The Singapore Epidemiology of Eye Diseases Study

We examined the joint effects of intraocular pressure (IOP) and myopia on the risk of primary open angle glaucoma (POAG) in a multi-ethnic Asian population. A total of 9,422 participants (18,469 eyes) in the Singapore Epidemiology of Eye Diseases Study were included. Of them, 213 subjects (273 eyes) had POAG. All participants underwent standardised examinations. The independent and joint effects of IOP and myopia on POAG were examined using logistic regression models. Generalised estimating equation models were used to account for correlation between eyes. Higher IOP, longer axial length, and more negative spherical equivalent were independently associated with POAG, after adjusting for relevant covariates (all P ≤ 0.005). Significant interaction between IOP and myopia on POAG was observed (P interaction = 0.025). Eyes with moderate-to-high myopia (<-3.0 dioptres) with high IOP (≥20 mmHg) were 4.27 times (95% CI, 2.10-8.69) likely to have POAG, compared to eyes without myopia (>-0.5 dioptres) and with IOP <20 mmHg. Eyes with AL of ≥25.5 mm and high IOP (≥20 mmHg) were 16.22 times (95% CI, 7.73 to 34.03) likely to have POAG, compared to eyes with shorter AL (<23.5 mm) and lower IOP (<20 mmHg). These findings may provide additional insights into the pathophysiology of POAG and are particularly relevant for Asian populations.