Open-angle glaucoma and ocular hypertension: the Long Island Glaucoma Case-control Study

Acute alcohol consumption modulates corneal biomechanical properties as revealed by optical coherence elastography

Acute alcohol ingestion has been found to impact visual functions, including eye movement, but its effects on corneal biomechanical properties remain unclear. This study aimed to investigate the influence of acute alcohol consumption on corneal biomechanical properties using optical coherence elastography (OCE). An air-coupled ultrasound transducer induced elastic waves in mice corneas in vivo, and a high-resolution phase-sensitive optical coherence tomography (OCT) system tracked the mechanical waves to quantify the elastic wave speed. In vivo measurements were performed on three groups of age- and gender-matched mice: control, placebo (administered saline), and alcohol (administered ethanol) groups. Longitudinal measurements were conducted over a one-hour period to assess acute temporal changes in wave speeds, which are associated with inherent biomechanical properties of the cornea. The results showed a significant decrease in wave speed for the alcohol group after 10 min of ingestion in comparison to pre-ingestion values (p = 0.0096), whereas the temporal wave speed changes for the placebo group were statistically insignificant (p = 0.076). In contrast, the control group showed no significant changes in elastic wave speed and corneal thickness. Furthermore, a significant difference was observed between the wave speeds of the placebo and alcohol groups at each measurement time point between 10 and 50 min (p < 0.05), though both groups exhibited a similar trend in corneal thickness change. The findings of this study have important implications for clinical assessments and research in corneal disorders, highlighting the potential of OCE as a valuable tool for evaluating such changes.

Association Between Alcohol Consumption Patterns and Glaucoma in Japan

PRCIS

In this case-control study of the Japanese population, including 3207 glaucoma cases, alcohol consumption patterns such as frequency and quantity showed a positive association with glaucoma prevalence.

PURPOSE

To examine the association between alcohol consumption patterns and glaucoma.

SUBJECTS AND METHODS

This case-control study evaluated 3207 cases with glaucoma and 3207 matched controls. Patients over 40 years of age were included from 1,693,611 patients admitted to 34 hospitals in Japan. Detailed alcohol consumption patterns (drinking frequency, average daily drinks, and total lifetime drinks) were obtained, as well as various confounding factors, including smoking history and lifestyle-related comorbidities. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% CIs for glaucoma prevalence.

RESULTS

Drinking frequency showed an association with glaucoma for "a few days/week" (OR, 1.19; 95% CI, 1.03-1.38) and "almost every day/week" (OR, 1.40; 95% CI, 1.18-1.66). Average daily drinks showed an association for ">0-2 drinks/day" (OR, 1.16; 95% CI, 1.03-1.32). Total lifetime drinks showed an association for ">60-90 drink-year" (OR, 1.23; 95% CI, 1.01-1.49) and ">90 drink-year" (OR, 1.23; 95% CI, 1.05-1.44). As alcohol consumption levels differed considerably between men and women, additional analyses were conducted separately for men and women. Among men, drinking frequency of "a few days/week" and "almost every day/week," average daily drinks of ">0-2 drinks/day" and ">2-4 drinks/day," and total lifetime drinks of ">60-90 drink-year" and ">90 drink-year" had an association with glaucoma. Conversely, among women, neither drinking frequency, average daily drinks, nor total lifetime drinks were associated.

CONCLUSIONS

Both the frequency and quantity of alcohol consumption were associated with glaucoma. Further research on gender differences is warranted.

Associations of smoking and alcohol consumption with the development of open angle glaucoma: a retrospective cohort study

OBJECTIVES

To investigate the associations of alcohol consumption and smoking with the development of perimetric glaucoma in patients with suspected glaucoma.

DESIGN

A retrospective cohort study of patients suspected to have glaucoma enrolled in the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES).

SETTING

Three tertiary glaucoma centres in the USA.

PARTICIPANTS

825 eyes of 610 patients with glaucoma suspect eyes with normal visual fields (VF) at baseline were followed over an average of 9 years from the DIGS and ADAGES studies.

OUTCOME MEASURES

Development of glaucoma was defined as occurrence of three consecutive abnormal VF tests during follow-up. Univariable and multivariable Cox regression models were used to investigate lifestyle-related factors associated with development of VF loss over time.

RESULTS

VF tests were abnormal three times in a row in 235 (28.5%) eyes. Alcohol consumption was associated with a higher risk of developing glaucoma (HR 1.57, 95% CI 1.03 to 2.38, p=0.037). In men, the risk of developing glaucoma in alcohol drinkers (HR 1.92, 95% CI 1.00 to 3.68, p=0.048) was greater than non-alcohol drinkers. In individuals of African descent, the risk of developing glaucoma in alcohol drinkers (HR 1.79, 95% CI 1.02 to 3.15, p=0.043) was greater than non-alcohol drinkers. Age was a modifier of the relationship between smoking and glaucomatous VF defects (p=0.048). The risk of developing glaucoma in smokers (HR 1.73, 95% CI 1.10 to 2.72, p=0.019) was greater than never smokers after adjustment for confounding factors in older patients (age >61 years).

CONCLUSION

Alcohol consumption was associated with an increased risk of developing glaucoma, particularly in men and individuals of African descent. The risk of developing glaucoma among smokers suspected of having glaucoma was influenced by age, with older individuals having a higher risk than younger people.

TRIAL REGISTRATION NUMBER

NCT00221897 and NCT00221923.

Towards modifying the genetic predisposition for glaucoma: An overview of the contribution and interaction of genetic and environmental factors

Glaucoma, the leading cause of irreversible blindness worldwide, is a complex human disease, with both genetic and environmental determinants. The availability of large-scale, population-based cohorts and biobanks, combining genotyping and detailed phenotyping, has greatly accelerated research into the aetiology of glaucoma in recent years. Hypothesis-free genome-wide association studies have furthered our understanding of the complex genetic architecture underpinning the disease, while epidemiological studies have provided advances in the identification and characterisation of environmental risk factors. It is increasingly recognised that the combined effects of genetic and environmental factors may confer a disease risk that reflects a departure from the simple additive effect of the two. These gene-environment interactions have been implicated in a host of complex human diseases, including glaucoma, and have several important diagnostic and therapeutic implications for future clinical practice. Importantly, the ability to modify the risk associated with a particular genetic makeup promises to lead to personalised recommendations for glaucoma prevention, as well as novel treatment approaches in years to come. Here we provide an overview of genetic and environmental risk factors for glaucoma, as well as reviewing the evidence and discussing the implications of gene-environment interactions for the disease.

Alcohol, intraocular pressure and open-angle glaucoma: A systematic review and meta-analysis

Topic

This systematic review and meta-analysis summarizes the existing evidence for the association of alcohol use with intraocular pressure (IOP) and open-angle glaucoma (OAG).

Clinical Relevance

Understanding and quantifying these associations may aid clinical guidelines or treatment strategies and shed light on disease pathogenesis. The role of alcohol, a modifiable factor, in determining IOP and OAG risk also may be of interest from an individual or public health perspective.

Methods

The study protocol was preregistered in the Open Science Framework Registries (https://osf.io/z7yeg). Eligible articles (as of May 14, 2021) from 3 databases (PubMed, Embase, Scopus) were independently screened and quality assessed by 2 reviewers. All case-control, cross-sectional, and cohort studies reporting a quantitative effect estimate and 95% confidence interval (CI) for the association between alcohol use and either IOP or OAG were included. The evidence for the associations with both IOP and OAG was qualitatively summarized. Effect estimates for the association with OAG were pooled using random effects meta-analysis. Studies not meeting formal inclusion criteria for systematic review, but with pertinent results, were also appraised and discussed. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

Results

Thirty-four studies were included in the systematic review. Evidence from 10 studies reporting an association with IOP suggests that habitual alcohol use is associated with higher IOP and prevalence of ocular hypertension (IOP > 21 mmHg), although absolute effect sizes were small. Eleven of 26 studies, comprising 173 058 participants, that tested for an association with OAG met inclusion criteria for meta-analysis. Pooled effect estimates indicated a positive association between any use of alcohol and OAG (1.18; 95% confidence interval [CI], 1.02–1.36; P = 0.03; I² = 40.5%), with similar estimates for both prevalent and incident OAG. The overall GRADE certainty of evidence was very low.

Conclusions

Although this meta-analysis suggests a harmful association between alcohol use and OAG, our results should be interpreted cautiously given the weakness and heterogeneity of the underlying evidence base, the small absolute effect size, and the borderline statistical significance. Nonetheless, these findings may be clinically relevant, and future research should focus on improving the quality of evidence.

Alcohol and the Eye

In this article, we present a review of ocular conditions related to alcohol consumption. A search of the literature published from 1952 to March 2020 was performed. The titles and abstracts were screened and the eligible studies were selected. PubMed, ISI Web of Knowledge database, Scopus, Embase, and the Cochrane Library were searched. We categorized the relationship between alcohol intake and ocular conditions by the type of ocular exposure to alcohol. Accordingly, ocular findings following acute alcohol intoxication, optic neuropathy following methanol toxicity, congenital conditions related to maternal alcohol consumption, and ocular disease related to chronic alcoholism are discussed. The main feature of alcohol intoxication in the eye is abnormal eye movement. Acute optic neuropathy secondary to methyl alcohol consumption is a serious ocular disease with permanent vision loss or scotoma. Prenatal exposure to ethanol may end in fetal alcohol spectrum disease, where ocular findings are a constant component. The association between chronic alcohol consumption and increased risks of cataract, age-related macular degeneration, diabetic retinopathy, different types of optic neuropathy, impairment of visual quality, retinal vascular disease, and ocular surface disease has also been reported. Along with detrimental medical and social effects, the role of alcohol consumption in different ocular conditions should be considered, as alcohol-induced visual disturbances may contribute to the heavy burden of alcohol abuse on the healthcare system and overall quality of life.

Effects of Consumption of Alcohol on Intraocular Pressure: Korea National Health and Nutrition Examination Survey 2010 to 2011

This study researched the association between alcohol consumption, intraocular pressure (IOP), and risk of open-angle glaucoma (OAG) using nationwide population-based cross-sectional data from the Korean population based survey. Information on alcohol intake was obtained by questionnaire and comprehensive ophthalmic examinations were performed. Among a total of 6057 participants, the prevalence of OAG was 4.4% (6.0% for men and 3.0% for women). Multivariate adjusted models showed that alcohol consumption showed significant relationship with changes in IOP. In sex-stratified analyses, alcohol consumption more than 2 times per week was associated with increased IOP in men without OAG, while in women with OAG drinking alcohol more than 4 times per week was associated with increased IOP. This study showed significant differences between men and women without glaucoma who consumed alcohol more than four times per week (p-value: 0.03). Our results suggest that alcohol consumption is associated with risk of elevated IOP depending on sex and presence of glaucoma in Koreans. Therefore, patients who need to control IOP should consider the effects of alcohol consumption.

In Vivo Measurements of Prelamina and Lamina Cribrosa Biomechanical Properties in Humans

Purpose

To develop and use a custom virtual fields method (VFM) to assess the biomechanical properties of human prelamina and lamina cribrosa (LC) in vivo.

Methods

Clinical data of 20 healthy, 20 ocular hypertensive (OHT), 20 primary open-angle glaucoma, and 16 primary angle-closure glaucoma eyes were analyzed. For each eye, the intraocular pressure (IOP) and optical coherence tomography (OCT) images of the optic nerve head (ONH) were acquired at the normal state and after acute IOP elevation. The IOP-induced deformation of the ONH was obtained from the OCT volumes using a three-dimensional tracking algorithm and fed into the VFM to extract the biomechanical properties of the prelamina and the LC in vivo. Statistical measurements and P values from the Mann-Whitney-Wilcoxon tests were reported.

Results

The average shear moduli of the prelamina and the LC were 64.2 ± 36.1 kPa and 73.1 ± 46.9 kPa, respectively. The shear moduli of the prelamina of healthy subjects were significantly lower than those of the OHT subjects. Comparisons between healthy and glaucoma subjects could not be made robustly due to a small sample size.

Conclusions

We have developed a methodology to assess the biomechanical properties of human ONH tissues in vivo and provide preliminary comparisons in healthy and OHT subjects. Our proposed methodology may be of interest for glaucoma management.

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.

Retinal structure and function in monkeys with fetal alcohol exposure

Exposure to ethanol in utero leads to several brain development disorders including retinal abnormalities whose underlying cellular pathogenesis remains elusive. We recently reported that fetal alcohol exposure (FAE) in vervet monkeys induces anomalies of full-field electroretinogram (ERG) waveforms that suggest premature aging of the retina. The goal of this study is to characterize the anatomo-functional mechanisms underlying the retinal changes observed in fetal alcohol exposed (FAE) monkeys, and age- and sex-matched normals. First, we examined in vivo the fundus of the eyes, measured intraocular pressure (IOP) and assessed cone activity using flicker ERG. Second, we investigated ex vivo, protein expression and anatomical organization of the retina using Western blotting, classical histology and immunohistochemistry. Our results indicated that the fundus of the eyes showed both, increased vascularization (tessellated fundus) and IOP in FAE monkeys. Furthermore, light-adapted flicker responses above 15 Hz were also significantly higher in FAE monkeys. Although there were no obvious changes in the overall anatomy in the FAE retina, Glial Fibrillary Acidic Protein (GFAP, a potent marker of astrocytes) immunoreactivity was increased in the FAE retinal ganglion cell layer indicating a strong astrogliosis. These alterations were present in juvenile (2 years old) monkeys and persist in adults (8 years old). Moreover, using specific cell type markers, no significant modifications in the morphology of the photoreceptors, horizontal cells, bipolar cells, and amacrine cells were observed. Our data indicate that FAE does indeed induce anatomical changes within the retinal ganglion cell layer that are reflected in the increased photosensitivity of the cone photoreceptors.

Lifestyles guide and glaucoma (II). Diet, supplements, drugs, sleep, pregnancy, and systemic hypertension

PURPOSE

To establish evidence based guidelines to advise patients on the relationship between habits, diet, certain circumstances, diseases and glaucoma.

METHODS

Review of all published articles on glaucoma and sports or other activities. The papers were classified according to the level of scientific evidence based on the Oxford Centre for Evidence-based Medicine classification.

RESULTS

The evidence on the relationship between diet or supplements and the incidence or progression of glaucoma is insufficient to make a general recommendation for glaucoma patients. Although some studies on normal tension glaucoma suggest that Gingko biloba could reduce glaucoma progression, the results do not allow a general recommendation for all these patients. Similarly, the evidence on the usefulness of vitamin supplements is not conclusive. The studies on smoking do not clearly demonstrate the relationship between this habit and incidence of glaucoma. Marihuana is not a useful treatment for glaucoma. Although the results on the relationship between sleep apnoea and glaucoma are heterogeneous, it is recommended that patients with moderate to intense apnoea are tested for glaucoma. Pregnancy does not influence the course of the disease, but several hypotensive drugs may be harmful for the foetus. Nocturnal systemic hypotension is a risk factor for glaucoma progression.

CONCLUSIONS

Certain habits, circumstances, or diseases may have an influence on the onset or progression of glaucoma. It is important to have adequate information about the scientific evidence in the publications in order to properly advise patients.

Src Family Kinase Links Insulin Signaling to Short Term Regulation of Na,K-ATPase in Nonpigmented Ciliary Epithelium

Insulin has been shown to elicit changes of Na,K-ATPase activity in various tissues. Na,K-ATPase in the nonpigmented ciliary epithelium (NPE) plays a role in aqueous humor secretion and changes of Na,K-ATPase activity impact the driving force. Because we detect a change of NPE Na,K-ATPase activity in response to insulin, studies were carried out to examine the response mechanism. Ouabain-sensitive rubidium (Rb) uptake by cultured NPE cells, measured as a functional index of Na,K-ATPase-mediated inward potassium transport, was found to increase in cells exposed for 5 min to insulin. The maximally effective concentration was 100 nM. An intrinsic increase of Na,K-ATPase activity evident as a >2-fold increase in the rate of ouabain-sensitive ATP hydrolysis in homogenates obtained from cells exposed to 100 nM insulin for 5 min was also observed. Insulin-treated cells exhibited Akt, Src family kinase (SFK), ERK1/2, and p38 activation, all of which were prevented by a pI3 kinase inhibitor LY294002. The Rb uptake and Na,K-ATPase activity response to insulin both were abolished by PP2, an SFK inhibitor which also prevented p38 and ERK1/2 but not Akt activation. The Akt inhibitor MK-2206 did not change the Na,K-ATPase response to insulin. The findings suggest insulin activates pI3K-dependent Akt and SFK signaling pathways that are separate. ERK1/2 and p38 activation is secondary to and dependent on SFK activation. The increase of Na,K-ATPase activity is dependent on activation of the SFK pathway. The findings are consistent with previous studies that indicate a link between Na,K-ATPase activity and SFK signaling. J. Cell. Physiol. 232: 1489-1500, 2017. © 2016 Wiley Periodicals, Inc.

Association of NT-proANP Level in Plasma and Humor Aqueous with Primary Open-Angle Glaucoma

PURPOSE

The aim of this study is to determine differences in the levels of NT-proANP in the plasma and aqueous humor of glaucoma and cataract patients and to evaluate whether any relationships are present.

METHODS

The study group consisted of 58 patients with primary-open glaucoma (POAG) undergoing trabeculectomy surgery. The control group was comprised of 32 age-matched cataract patients. The concentration of the N-terminal fragment of the proatrial natriuretic peptide (NT-proANP, 1-98) in the aqueous humor and blood plasma samples was measured using an immunochemical method (ELISA).

RESULTS

The plasma NT-proANP concentration was significantly increased in patients with POAG compared to that in the control group (7.00 vs. 4.65 nmol/L, P = 0.0054). Similarly, the NT-proANP concentration in the aqueous humor was significantly higher in the POAG patients (0.47 vs. 0.09 nmol/L, P = 0.0112). However, there was no correlation between the NT-proANP values in the aqueous humor and the plasma of the POAG patients, as well as between the NT-proANP values in the aqueous humor and the intraocular pressure.

CONCLUSIONS

We identified an association between the levels of NT-proANP in the plasma and the aqueous humor with POAG. Our data support the idea of the involvement of NP system in the development of POAG and highlight ANP as a possible biomarker of glaucoma.

Patients with Primary Open-Angle Glaucoma May Develop Ischemic Heart Disease More Often than Those without Glaucoma: An 11-Year Population-Based Cohort Study

OBJECTIVES

To investigate whether patients with primary open angle glaucoma (POAG) have a higher proportion of ischemic heart disease (IHD) development.

DESIGN

A population-based retrospective cohort study, using the National Health Insurance Database (NHID) from 1st January, 2001, to 31st December, 2011, in Taiwan.

METHODS

3510 subjects with POAG were enrolled into the POAG group and 14040 subjects without glaucoma into the comparison group. The comparison group consisted of randomly selected individuals, matched with the POAG group based on age, gender, and index date (date of enrollment) at a ratio of 1:4. The participants of both groups should have no IHD before the index date, and they were followed until the end of 2011 to see whether they had new-onset IHD or not. Kaplan-Meier curves were used to compare the cumulative incidence of IHD between the two groups. Frailty model, a specialized form of Cox regression analysis, was used to estimate the crude and adjusted hazard ratio (HR) of IHD. Analyses were adjusted by age, gender, and systemic comorbidities (i.e. diabetes, hypertension, hyperlipidemia, atrial fibrillation and congestive heart failure).

RESULTS

The mean age of the cohort was 57.6±11.0 years. There were slightly more males than females (51.6% vs. 48.4%). A log-rank test comparing Kaplan-Meier curves of the two groups revealed a significantly higher cumulative incidence of IHD in the POAG group (p-value<0.001). In the univariate analysis by Frailty model, POAG patients had a significantly higher hazard of IHD (unadjusted HR = 2.32; 95% confidence interval 1.93 to 2.79). After adjustment, results remained significant (adjusted HR = 1.41; 95% confidence interval 1.16 to 1.72).

CONCLUSION

People with POAG may suffer from IHD more often than those without glaucoma.

Corn silk aqueous extracts and intraocular pressure of systemic and non-systemic hypertensive subjects

BACKGROUND

Hypotensive properties have been attributed to the stigma/style of Zea mays L (corn silk). Although the effect of corn silk extract on blood pressure has been documented in animal studies, we are not aware of any study on its effect on human blood pressure and intraocular pressure.

METHODS

A randomised study was carried out on the effect of water only, masked doses of corn silk aqueous extract (60, 130, 192.5 and 260 mg/kg body weight) on intraocular pressure and blood pressure of 20 systemic and 20 non-systemic hypertensive subjects. Intraocular pressure and blood pressure were measured at baseline and every hour for eight hours after administering water or a masked dose of corn silk aqueous extract. Each dose was administered at two-week intervals to each subject in the two study groups.

RESULTS

The results showed that the last three doses of corn silk aqueous extract gave a statistically significant reduction (p < 0.001) in mean intraocular pressure and blood pressure within eight hours of administration. The peak effect on intraocular pressure was observed after four hours and this was preceded by the peak effect on blood pressure, which occurred after three hours of administration. The hypotensive effect was dose-dependent in the two groups.

CONCLUSION

Corn silk aqueous extract has a lowering effect on intraocular pressure in systemic and non-systemic hypertensive subjects. This may have resulted from the fall in blood pressure that is due to potassium-induced natriuresis and diuresis caused by the high potassium content in the high doses of the corn silk extract.

Effects of antiglaucoma drugs on blood flow of optic nerve heads and related structures

An association between glaucoma development or progression and compromised ocular blood flow has been postulated as a result of population-based studies and prospective cohort studies. Blood flow in the optic nerve head (ONH) is of primary importance in the pathogenesis of glaucoma. The potential to modify the blood flow in the ONH and its related structures has been reported in various agents, including topical antiglaucoma drugs and systemic drugs such as calcium channel antagonists, which are reviewed in this manuscript. Clinical implications of the improvement in ocular blood flow on the treatment of glaucomatous optic neuropathy require further investigation.

Australian and New Zealand Registry of Advanced Glaucoma: methodology and recruitment

BACKGROUND

  Glaucoma is a sight-threatening disease affecting 3% of the population over the age of 50. Glaucoma is treatable, and severe vision loss can usually be prevented if diagnosis is made at an early stage. Genetic factors play a major role in the pathogenesis of the condition, and therefore, genetic testing to identify asymptomatic at-risk individuals is a promising strategy to reduce the prevalence of glaucoma blindness. Furthermore, unravelling genetic risk factors for glaucoma would also allow a better understanding of the pathogenesis of the condition and the development of new treatments.

DESIGN

  The Australian and New Zealand Registry of Advanced Glaucoma is a prospective study that aims to develop a large cohort of glaucoma cases with severe visual field loss to identify novel genetic risk factors for glaucoma blindness.

METHODS

  Clinical information and blood are collected from participants after referral by eye practitioners. Samples are collected across Australia and New Zealand using postage kits.

PARTICIPANTS

  Our registry has recruited just over 2000 participants with advanced glaucoma, as well as secondary and developmental glaucomas.

RESULTS

  A positive family history of glaucoma is present in more than half of the advanced glaucoma cases and the age at diagnosis is significantly younger for participants with affected relatives, which reinforces the involvement of genetic factors in glaucoma.

CONCLUSIONS

  With the collection of glaucoma cases recruited so far, our registry aims to identify novel glaucoma genetic risk factors to establish risk profiling of the population and protocols for genetic testing.

Risk factors for primary open-angle glaucoma in Japanese subjects attending community health screenings

Background/aims

To describe risk factors associated with primary open-angle glaucoma (POAG) in Japanese subjects who participated in community health screenings.

Methods

Residents of Akita, Japan, participating in a community health checkup were selected to undergo a comprehensive ophthalmic examination. Glaucoma was diagnosed based on optic disk appearance, perimetric results, and other ocular findings. Systemic blood pressure and intraocular pressure were measured and ocular perfusion pressure was calculated. Logistic regression analysis was performed to determine risk factors for POAG patients.

Results and conclusion

Of the 710 subjects examined, 26 had POAG. The estimated prevalence of POAG was 3.7%. After adjusting for age, the prevalence of POAG was similar to that found in the Tajimi Study of Japanese subjects. Multivariate logistic regression analysis demonstrated that older age (≥60 years, odds ratio [OR]: 3.49), lower diastolic blood pressure (≤58 mmHg, OR: 2.11), higher intraocular pressure (≥19 mmHg, OR: 4.12), and lower ocular perfusion pressure (≤34 mmHg, OR: 5.78) were associated with increased risk of having POAG. These findings may be relevant for identifying high risk groups.

Dysfunctional regulation of ocular blood flow: A risk factor for glaucoma?

Primary open angle glaucoma (OAG) is a multifactorial optic neuropathy characterized by progressive retinal ganglion cell death and associated visual field loss. OAG is an emerging disease with increasing costs and negative outcomes, yet its fundamental pathophysiology remains largely undetermined. A major treatable risk factor for glaucoma is elevated intraocular pressure (IOP). Despite the medical lowering of IOP, however, some glaucoma patients continue to experience disease progression and subsequent irreversible vision loss. The scientific community continues to accrue evidence suggesting that alterations in ocular blood flow play a prominent role in OAG disease processes. This article develops the thesis that dysfunctional regulation of ocular blood flow may contribute to glaucomatous optic neuropathy. Evidence suggests that impaired vascular autoregulation renders the optic nerve head susceptible to decreases in ocular perfusion pressure, increases in IOP, and/or increased local metabolic demands. Ischemic damage, which likely contributes to further impairment in autoregulation, results in changes to the optic nerve head consistent with glaucoma. Included in this review are discussions of conditions thought to contribute to vascular regulatory dysfunction in OAG, including atherosclerosis, vasospasm, and endothelial dysfunction.

A prospective study of diabetes, lifestyle factors, and glaucoma among African-American women

PURPOSE

To evaluate the association of self-reported type 2 diabetes, anthropometric factors, alcohol consumption, and cigarette smoking with risk of primary open-angle glaucoma (POAG) in a prospective cohort study of African-American women.

METHODS

From 1995 through 2007, 32,570 Black Women's Health Study participants aged 21 to 69 years at baseline were followed for incident POAG. Questionnaires were mailed biennially to update exposures and identify incident cases of POAG. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were derived from Cox regression models.

RESULTS

During 416,171 person-years of follow-up, 366 incident POAG cases were confirmed by physician report. After adjustment for potential confounders, the IRR comparing women with and without type 2 diabetes was 1.58 (95% CI, 1.17-2.13), and the IRR comparing current with never alcohol consumers was 1.35 (95% CI, 1.05-1.73). Among women younger than 50, associations with diabetes and alcohol consumption were stronger, and POAG was significantly associated with body mass index, waist circumference, waist-to-hip ratio, and both long-duration and high-intensity current smoking.

CONCLUSIONS

These results suggest that type 2 diabetes and current alcohol consumption are independent risk factors for POAG among African-American women, and that in addition to those factors, overall and central adiposity and smoking may be associated with increased risk of early-onset POAG.

Intraocular pressure fluctuations in professional brass and woodwind musicians during common playing conditions

BACKGROUND

We investigated the effects on intraocular pressure (IOP) and blood pressure (BP) of playing brass and woodwind instruments by monitoring IOP and BP in a representative group of professional musicians under a variety of common playing conditions.

METHODS

IOP and BP measurements were recorded from 37 brass and 15 woodwind instrument players, before and after playing tones of low, middle and high frequency. We also measured IOP and BP before and during playing common exercises of 10 minutes duration, as well as after playing a sustained high-pitched tone, to test for changes in IOP under conditions of maximum effort.

RESULTS

Playing tones on brass and woodwind instruments causes a temporary elevation in IOP and BP, depending on the tone frequency: brass instrument players showed a significant elevation after playing high and middle frequency tones (p < 0.0001) whereas woodwind instrument players showed a significant increase only for high frequencies (e.g., oboe, 17 ± 2.9 mm Hg to 21 ± 4.4 mm Hg; p = 0.017). Playing a typical exercise of 10 minutes temporarily increased IOP in both groups of musicians. Finally, playing a sustained tone of high pitch caused a significant elevation in IOP in brass instrument players only (16.6 ± 3.5 mm Hg to 23.3 ± 8.9 mm Hg; p < 0.0001).

CONCLUSIONS

The temporary and sometimes dramatic elevations and fluctuations in IOP observed in this study, coupled with daily exposure to instrument play, puts professional wind instrument players at increased risk of developing glaucoma. Consequently, these musicians should be monitored for signs of glaucoma, especially those with co-existing risk factors.

Lifestyle, nutrition, and glaucoma

The only proven strategy to prevent primary open-angle glaucoma (POAG) is the use of ocular hypotensive therapy among people diagnosed with ocular hypertension. In this review, various modifiable lifestyle factors, such as exercise, diet, and cigarette smoking, that may influence intraocular pressure and that have been studied in relation to the risk of developing POAG are discussed. Epidemiologic studies on lifestyle factors are few, and the current evidence suggests that there are no environmental factors that are clearly associated with POAG; however, a few factors merit further study. This review also outlines future directions for research into the primary prevention of POAG.

Open-Angle Glaucoma—An Epidemiologic Overview

PURPOSE

To provide a summary overview of current epidemiologic data on open-angle glaucoma.

METHODS

Literature review.

RESULTS

The review summarizes information on the following topics: Definition of open-angle glaucoma; Prevalence data from studies conducted in various populations; Incidence data available from population studies; Risk factors, categorized as demographic, familial, systemic, and ocular; and, Progression factors. It concludes by outlining the epidemiologic contributions to glaucoma and suggesting research needs.

CONCLUSIONS

Epidemiologic studies have contributed greatly to our knowledge of open-angle glaucoma. Still, many gaps remain, and the multifactorial etiology of glaucoma needs further clarification. Future research would benefit by standardizing the approach to define the disease, thus allowing better comparability across studies. A major priority is to achieve a better understanding of risk factors, which are likely to involve gene-environment interactions.

Associations with intraocular pressure in Latinos: the Los Angeles Latino Eye Study

PURPOSE

To evaluate the association of biologic factors with intraocular pressure (IOP) in a Latino population.

DESIGN

Population-based cross-sectional study.

METHODS

Latinos 40 years and older (n = 5,958) from the Los Angeles Latino Eye Study without a history of ocular hypotensive treatment underwent an interviewer-administered questionnaire and a complete ocular and clinical examination. IOP was obtained by applanation tonometry and was based on the mean of three measurements. Multivariable regression models were used to evaluate the independent association of biological factors with IOP.

RESULTS

Higher systolic blood pressure, higher central corneal thickness, and diabetes mellitus were the major factors associated with elevated IOP. Other positively correlated variables included age, female gender, higher diastolic blood pressure, larger body mass index, darker colored irides, and nuclear sclerosis. Axial length and family history of glaucoma had no association with IOP.

CONCLUSIONS

Several systemic and ocular characteristics are associated with elevated IOP in Latinos. By identifying and recognizing these risk factors, we can define subgroups of the population that may be most at risk of having elevated IOP.

Risk Factors for Incident Open-angle Glaucoma

PURPOSE

To evaluate risk factors for definite open-angle glaucoma (OAG), based on African-descent participants of the Barbados Eye Studies.

DESIGN

Cohort study with 81% to 85% participation over 9 years' follow-up.

PARTICIPANTS

We evaluated 3222 persons at risk, 40 to 84 years old, who did not have definite OAG at baseline.

METHODS

Participants had standardized study visits at baseline and after 4 and 9 years, with structured interviews, blood pressure (BP), and other measurements. The ophthalmic protocol included automated perimetry, applanation tonometry, fundus photography, and comprehensive ophthalmologic examinations for those referred. Central corneal thickness (CCT) was measured in a subset at the 9-year examination. Incidence was estimated by the product-limit approach; relative risk ratios (RRs) with 95% confidence intervals (CIs) were based on Cox regression models with discrete time.

MAIN OUTCOME MEASURE

Nine-year incidence of definite OAG.

RESULTS

Over 9 years, 125 persons developed definite OAG (incidence, 4.4%; 95% CI, 3.7-5.2). Baseline factors influencing risk were age (RR, 1.04; 95% CI, 1.02-1.05 per year); family history of glaucoma (RR, 2.4; 95% CI, 1.3-4.6); higher intraocular pressure (IOP) (RR, 1.12; 95% CI, 1.08-1.16 per mmHg); lower systolic BP (RR, 0.91; 95% CI, 0.84-1.00 per 10 mmHg); and lower ocular systolic, diastolic, and mean perfusion pressures (RR, 0.66; 95% CI, 0.54-0.80 per 10 mmHg higher mean perfusion pressure) (RR, 2.6; 95% CI, 1.4-4.6 for low mean perfusion pressure [<40 mmHg]). Thinner CCT was also associated with OAG incidence (odds ratio, 1.41; 95% CI, 1.01-1.96 per 40 mum lower).

CONCLUSIONS

This is the first report of risk factors for long-term OAG incidence; it is also based on a sizable number of new cases. Incidence was high in this African-descent population, where the established factors of older age, higher IOP, and family history contributed to risk. Additional predictors were vascular factors, including lower systolic BP, and particularly lower ocular perfusion pressures, which more than doubled risk. Thinner CCT was also a factor. These findings indicate a multifactorial etiology of OAG and suggest that similar risk factors apply across populations. Results are relevant for understanding OAG causation and identifying groups at high risk.

Predictors of Long-term Progression in the Early Manifest Glaucoma Trial

PURPOSE

To determine progression factors at the end of the Early Manifest Glaucoma Trial (EMGT) based on all EMGT patients and evaluate separately patients with higher and lower baseline intraocular pressure (IOP; median split).

DESIGN

Cohort of clinical trial participants.

PARTICIPANTS

Patients with early open-angle glaucoma randomized to argon laser trabeculoplasty plus betaxolol (n = 129) or no immediate treatment (n = 126), examined every 3 months for up to 11 years.

METHODS

Cox proportional hazard analyses, expressed by hazard ratios (HRs) and 95% confidence intervals (CIs).

MAIN OUTCOME MEASURE

Time to progression, defined by perimetric and photographic disc criteria.

RESULTS

Overall progression was 67% when follow-up ended (median, 8 years). Treatment approximately halved progression risk (HR, 0.53; 95% CI, 0.39-0.72); results were similar for patients with higher and lower baseline IOP (HRs, 0.41 and 0.55). Baseline progression factors (HRs, 1.51-2.12; P<0.01) were higher IOP, exfoliation, bilateral disease, and older age, as previously reported. New baseline predictors were lower ocular systolic perfusion pressure in all patients (< or =160 mmHg; HR, 1.42; 95% CI, 1.04-1.94), cardiovascular disease history (HR, 2.75; 95% CI, 1.44-5.26) in patients with higher baseline IOP, and lower systolic blood pressure (BP) (< or =125 mmHg; HR, 0.46; 95% CI, 0.21-1.02) in patients with lower baseline IOP. Postbaseline progression factors were IOP levels at follow-up, with 12% to 13% average increase per millimeter of mercury in all patients (HRs, 1.12-1.13 per mmHg higher) and similar results in patients with higher and lower baseline IOP (HRs, 1.15 and 1.13 per mmHg higher). Disc hemorrhages (HR, 1.02; 95% CI, 1.01-1.03 per percent higher frequency) also predicted progression. Thinner central corneal thickness (CCT) (HR, 1.25; 95% CI, 1.01-1.55 per 40 microm lower) was a new significant factor, a result observed in patients with higher baseline IOP (HR, 1.42; 95% CI, 1.05-1.92 per 40 microm lower) but not lower baseline IOP, with significant IOP-CCT interaction.

CONCLUSIONS

Treatment and follow-up IOP continued to have a marked influence on progression, regardless of baseline IOP. Other significant factors were age, bilaterality, exfoliation, and disc hemorrhages, as previously determined. Lower systolic perfusion pressure, lower systolic BP, and cardiovascular disease history emerged as new predictors, suggesting a vascular role in glaucoma progression. Another new factor was thinner CCT, with results possibly indicating a preferential CCT effect with higher IOP.

Prospective study of alcohol consumption and the risk of primary open-angle glaucoma

PURPOSE

Alcohol intake reduces intraocular pressure, a risk factor for primary open-angle glaucoma (POAG). We investigated whether alcohol consumption is associated with a reduced risk of POAG.

METHODS

We followed female nurses from 1980 and male health professionals from 1986 to 2002. Eligible participants were 40+ years old, did not have POAG, and reported receiving eye examinations during follow-up. Information on alcohol consumption, potential confounders and POAG diagnoses were updated by using biennial questionnaires. We identified 856 self-reported POAG cases that were confirmed with medical record review. Cohort-specific and pooled analyses across cohorts were conducted to calculate multivariable rate ratios (RR) of POAG.

RESULTS

Alcohol consumption<30 g/day did not influence POAG risk: compared with non-drinkers, the pooled RRs were 0.99 (95% Confidence Interval [CI]: 0.83-1.19) for drinking<10 g/day, 0.96 (95% CI: 0.76-1.22) for 10-19 g/day, and 0.95 (95% CI: 0.68-1.33) for 20-29 g/day. Although there were suggestive inverse associations with drinking>30 g/day (RR=0.71), this was not significant (95% CI: 0.49-1.04), and no significant linear associations were detected. Risks of POAG did not differ by type of alcoholic beverage consumed. To evaluate the potential for detection bias, we controlled for additional factors, such as frequency of eye exams, but results were similar.

CONCLUSION

In this large prospective study of men and women, alcohol consumption did not influence the risk of POAG.

Variations in treatment among adult-onset open-angle glaucoma patients

OBJECTIVE

To determine the predictors of treatment for glaucoma and suspect glaucoma in a nationally representative sample of diagnosed persons.

DESIGN

Retrospective cohort study of persons enrolled in a large managed care organization.

PARTICIPANTS

Thirty-five thousand seven hundred fifty-four diagnosed suspects, 5265 diagnosed glaucoma persons, and 2633 individuals coded as having cupping of the optic disc.

METHODS

Linked pharmacy and patient care information were used to examine the predictors of initiating glaucoma treatment in this cohort of persons insured by a single managed care organization. Predictors entered into logistic regression models included diagnostic group (suspect vs. diagnosed), age group, gender, region of the country, provider type at the initial visit (optometrist or ophthalmologist), diagnosis index date divided into 2 periods (1995-1998 and 1999-2001), and health plan enrollment duration after the initial diagnosis.

MAIN OUTCOME MEASURES

Occurrence of and factors associated with treatment for glaucoma (argon laser trabeculoplasty [ALT], surgery, or topical ocular hypotensives).

RESULTS

A logistic regression model adjusting for glaucoma status, age, region, clinician seen at initial visit, and index date found that women were less likely to undergo treatment (topical ocular hypotensives, ALT, or surgery) than men (odds ratio, 0.76; 95% confidence interval, 0.71-0.80). Factors other than gender that were associated with greater likelihood of treatment were glaucoma diagnosis, older age, region, and longer follow-up.

CONCLUSIONS

We have documented wide variation in treatment among individuals diagnosed as having glaucoma or as glaucoma suspects. Women were 24% less likely to be treated than men, and younger individuals were far less likely to be treated than older ones. Furthermore, treatment varied by region of the country. Understanding the sources of these variations will help in determining how to arrive at better management strategies for individuals with glaucoma and suspect glaucoma.

Elevated intraocular pressure is associated with insulin resistance and metabolic syndrome

BACKGROUND AND AIM

Elevated intraocular pressure (IOP), a well-known risk factor for glaucoma, has recently been shown to be associated with some metabolic complications and obesity. We investigated the link between IOP and metabolic disturbances, focusing especially on metabolic syndrome and insulin resistance.

METHODS

Eye examinations, including IOP measurement, were conducted on 943 subjects (533 men and 410 women). Body mass index (BMI), percent body fat, waist circumference, systolic and diastolic pressure, fasting insulin, glucose, lipids, and other metabolic parameters were measured. The homeostasis model assessment (HOMA) score and McAuley index were calculated to assess whole-body insulin resistance.

RESULTS

Both of these insulin resistance indices showed positive associations with IOP (p < 0.05), even after statistical adjustment for other risk factors. IOP was higher in participants with metabolic syndrome, as compared to those who did not have metabolic syndrome. The mean IOP tended to increase linearly with the presence of increasing numbers of components for metabolic syndrome.

CONCLUSIONS

These results suggest that insulin resistance might contribute to an explanation that would account for many previous findings concerning the association between IOP and obesity, hypertension, and diabetes.

Determinants and heritability of intraocular pressure and cup-to-disc ratio in a defined older population

PURPOSE

To investigate the heritability of intraocular pressure (IOP) and cup-to-disc ratio (CDR) in an older well-defined population.

DESIGN

Family-based cohort study.

PARTICIPANTS

Through the population-based Salisbury Eye Evaluation study, we recruited 726 siblings (mean age, 74.7 years) in 284 sibships.

METHODS

Intraocular pressure and CDR were measured bilaterally for all participants. The presence or absence of glaucoma was determined by a glaucoma specialist for all probands on the basis of visual field, optic nerve appearance, and history. The heritability of IOP was calculated as twice the residual between-sibling correlation of IOP using linear regression and generalized estimating equations after adjusting for age, gender, mean arterial pressure, race, self-reported diabetes status, and history of systemic steroid use. The heritability of CDR was calculated using the same model and adjustments as above, while also adjusting for IOP.

MAIN OUTCOME MEASURES

Heritability and determinants of IOP and CDR, and impact of siblings' glaucoma status on IOP and CDR.

RESULTS

We estimated the heritability to be 0.29 (95% confidence interval [CI], 0.12-0.46) for IOP and 0.56 (95% CI, 0.35-0.76) for CDR in this population. Mean IOP in siblings of glaucomatous probands was statistically significantly higher than in siblings of normal probands (mean difference, 1.02 mmHg; P = 0.017). The mean CDR in siblings of glaucomatous probands was 0.07 (or 19%) larger than in siblings of glaucoma suspect referrals (P = 0.045) and siblings of normal probands (P = 0.004).

CONCLUSIONS

In this elderly population, we found CDR to be highly heritable and IOP to be moderately heritable. On average, siblings of glaucoma patients had higher IOPs and larger CDRs than siblings of nonglaucomatous probands.

Intraocular pressure and systemic blood pressure: longitudinal perspective: the Beaver Dam Eye Study

AIM

To investigate the relation between change in systemic blood pressures and change in intraocular pressure.

METHODS

This was a population based study of people 43-86 years old living in Beaver Dam, Wisconsin. Measurements at baseline (1988-90) and 5 year follow up of systemic blood pressures, intraocular pressures, and history of use of blood pressure medications.

RESULTS

Intraocular pressures were significantly correlated with systolic and diastolic blood pressures at both baseline and follow up. There were significant direct correlations between changes in systemic blood pressures and changes in intraocular pressure. There was a 0.21 (95% CI: 0.16 to 0.27) mm Hg increase in IOP for a 10 mm Hg increase in systolic and 0.43 (0.35 to 0.52) mm Hg increase in IOP for a 10 mm Hg increase in diastolic blood pressure. Further adjustment for diabetes and medication use did not alter these associations. Decreased systolic or diastolic blood pressures of more than 10 mm Hg over 5 years were significantly associated with decreased IOP.

CONCLUSIONS

Reduced systemic blood pressure is associated with reduced intraocular pressure. This finding should be evaluated in other studies, especially with respect to the possibility of resultant decreased risk of open angle glaucoma.

An evidence-based assessment of risk factors for the progression of ocular hypertension and glaucoma

PURPOSE

To critically review the existing literature concerning risk factors for progression of ocular hypertension and glaucoma to assist in assigning levels of risk for individual patients.

DESIGN

Evidence-based review.

METHODS

A panel of physicians specializing in treatment of glaucoma patients was convened to critically analyze published population-based studies of ocular hypertension and glaucoma progression. The strength of evidence in support of reported risk factors was weighed.

RESULTS

Many putative risk factors for progression of ocular hypertension or glaucoma have been reported in the literature. The risk factors most strongly supported by evidence are higher intraocular pressure (IOP), greater cup-to-disk ratio, thinner central corneal measurement, and older age. Black race does not appear to be an independent risk factor, although black individuals tend to have thinner corneas, greater cup-to-disk ratios, and higher IOP, which increase their risk. The limited number of studies in which other suspected risk factors are reported prevents drawing firm conclusions about their importance at this time.

CONCLUSIONS

Only a subset of patients with ocular hypertension will eventually develop glaucoma. Decisions regarding the implementation and extent of therapy for ocular hypertension can be difficult and require an understanding of the relative importance of risk factors for progression. This review discusses the strength of evidence supporting reported risk factors and may be useful in assessing the risk for progression of individual patients.

Longevity-associated mitochondrial DNA 5178 A/C polymorphism is associated with intraocular pressure in Japanese men

BACKGROUND

Mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism has been reported to be associated with longevity in Japanese individuals, with experimental findings concluding that mt5178 A is an anti-atherogenic genotype. The aim of this study was to determine whether mt5178 A/C polymorphism influences intraocular pressure (IOP), and its relationship with the development of arteriosclerosis.

METHODS

Four hundred and forty-nine male volunteers who had visited a general hospital for medical check-up between August 1999 and August 2000 were enrolled. Of these, 386 Japanese men who had not undergone any medical treatment for hypertension, ocular hypertension or glaucoma were selected as subjects of this study. After these subjects were genotyped, a cross-sectional study regarding the relationship between genotype and IOP was conducted.

RESULTS

Mean IOP was significantly higher in men with mt5178 C (13.3 mmHg) than in those with mt5178 A (12.7 mmHg) (P = 0.037). This significant difference in mean IOP between the two genotypes remained evident after adjusting for age, body mass index, blood pressure, habitual smoking and habitual drinking. Interactions between mt5178 A/C polymorphism and habitual smoking or daily alcohol consumption with regard to IOP were observed. According to multiple regression analysis, habitual smoking was significantly associated with IOP in men with mt5178 A (P for trend = 0.020), while daily alcohol consumption was significantly associated with IOP in those with mt5178 C (P for trend = 0.021).

CONCLUSION

Longevity-associated mitochondrial DNA 5178 A/C polymorphism may be associated with IOP in Japanese men.

Does smoking affect intraocular pressure? Findings from the Blue Mountains Eye Study

PURPOSE

To assess the relationship between smoking and intraocular pressure.

MATERIALS AND METHODS

The Blue Mountains Eye Study examined 3654 residents aged 49 years and older in an area west of Sydney, Australia from 1992 to 1994. A trained interviewer collected a detailed history of smoking. Intraocular pressure was measured using Goldmann applanation tonometry; as the correlation between right and left eyes was very high, only right-eye data are presented. Participants using glaucoma medications or who had evidence of previous cataract surgery were excluded.

RESULTS

Current smokers (15.8% of participants) had slightly higher mean intraocular pressures (16.34 mm Hg) than nonsmokers (16.04 mm Hg). Intraocular pressure (in the right eye) was significantly associated with current smoking, after adjusting for age and sex (P = 0.03). This association remained unchanged after simultaneous adjustment for other variables associated with intraocular pressure, including blood pressure, diabetes, myopia, glaucoma, family history, and pseudoexfoliation (P = 0.02).

CONCLUSIONS

This study identified a modest cross-sectional positive association between current smoking and intraocular pressure.

Hypertension, diabetes, and longitudinal changes in intraocular pressure

PURPOSE

Diabetes and hypertension are recognized risk factors for raised intraocular pressure (IOP). This report examines the longitudinal relationship of hypertension and diabetes to a 4-year IOP change in a black population with high prevalence of these conditions.

DESIGN

Population-based cohort study of a simple random sample of residents of Barbados, West Indies, aged >/=40 years.

PARTICIPANTS

A total of 2996 persons without open-angle glaucoma or receiving IOP-lowering medication at baseline.

METHODS

Participants underwent standardized examinations including applanation tonometry, measurement of blood pressure, and anthropometric indices; a detailed interview; various ocular measurements; and venipuncture for glycosylated hemoglobin (GHb). Diabetes was defined by self-reported physician diagnosis and hypertension by blood pressure >/=140/90 mmHg and/or treatment history.

MAIN OUTCOME MEASURES

The 4-year person-based IOP change between baseline and follow-up was defined as the more positive IOP difference in either eye.

RESULTS

An IOP >21 mmHg at baseline was more likely in black and in mixed (black and white) participants (age-gender adjusted odds ratio [OR], 3.9 and 3.8, respectively) than in whites. Similarly, these groups had more hypertension (age-gender adjusted OR, 2.4 and 2.1, respectively) and diabetes (age-gender adjusted OR, 3.9 and 1.7, respectively) than did whites. Mean IOP in black participants increased by 2.5 (standard deviation, 3.9) mmHg over 4 years. Multiple regression analyses showed that baseline diabetes history and hypertension, as well as older age, elevated GHb, higher blood pressures, and lower baseline IOP were associated with a 4-year increase of IOP. The association between diabetes history/GHb and IOP increase became borderline/nonsignificant when persons who underwent cataract surgery during follow-up were excluded.

CONCLUSIONS

This report provides new data on the relationship of systemic factors to longitudinal increases in IOP in an African-origin population. Results highlight the increased risk of elevated IOP in populations with high prevalences of diabetes and hypertension.

Bias in self-reported family history and relationship to glaucoma: the Blue Mountains Eye Study

PURPOSE

To examine bias in the relationship between self-reported family history of glaucoma and its relationship to the prevalence of glaucoma and ocular hypertension.

METHODS

In a cross-sectional population-based study of 3654 Australians aged 49-97, participants were asked whether any first-degree relatives had been diagnosed with glaucoma. Open-angle glaucoma was diagnosed from matching optic disc and typical visual field changes, after gonioscopy. Ocular hypertension (OH) was diagnosed from elevated intraocular pressure (IOP) in subjects without glaucoma.

RESULTS

Glaucoma was present in 3.0% and ocular hypertension in 5.2% of subjects. A parent or sibling was reported to have glaucoma by 8.6%, including 10.5% of women and 5.9% of men. A positive family history was reported more frequently in parents (6.4%) than siblings (2.6%). Glaucoma was reported more frequently to affect mothers (5.0%) and sisters (1.6%) than fathers (1.5%) and brothers (1.2%). A first-degree family history was given by 15.7% of subjects with glaucoma compared to 8.3% of controls, odds ratio (OR) 3.2 (95% CI 1.8-5.6), after adjusting for glaucoma risk factors, including IOP. The association had a similar magnitude for a family history in parents and siblings. Although recall bias was evident from the finding of increased odds (OR 4.2) among previously diagnosed cases, the relationship with family history also persisted in newly-diagnosed cases (OR 2.4). A slightly stronger relationship was found between OH and glaucoma family history, OR 3.9 (95% CI 2.6-5.7), after adjusting for confounders, but was also strongly influenced by recall bias.

CONCLUSIONS

Although a positive family history of glaucoma may help to identify those at risk, it is subject to recall, selection and survival bias as well as community under-diagnosis of glaucoma and will most likely substantially underestimate the genetic influence.

Analysis of risk factors that may be associated with progression from ocular hypertension to primary open angle glaucoma

BACKGROUND

As a multifactorial disease, glaucoma may be associated with pressure-dependent and pressure-independent factors. Ocular hypertension (OHT) may develop into primary open angle glaucoma (POAG) for many patients. Groups with OHT and POAG were compared for pressure-dependent and independent risk factors. A high prevalence of any factor(s) could indicate a contribution to progression from OHT to POAG.

METHODS

A sample of patients with POAG (n = 438) and with OHT (n = 301) were selected from those attending a tertiary referral private glaucoma practice, and data were collected regarding age and intraocular pressure at the time of diagnosis, sex, family history of glaucoma, systemic hypertension, diabetes, Raynaud's phenomenon, migraine and myopia.

RESULTS

After multivariate analysis, older age at time of diagnosis (chi(2)(5) = 73.89, P < 0.001), myopia (odds ratio [OR] = 1.5, 95% confidence interval [CI] 1.0-2.2; P < 0.05), a family history of glaucoma (OR = 1.6, 95% CI 1.1-2.3; P < 0.01) and a high intraocular pressure (chi(2)(4) = 16.96; P = 0.002) were found to be more prevalent among those with POAG. No other significant differences could be found between the two groups.

CONCLUSION

Patients who have OHT may be at higher risk of developing POAG if they also have myopia, a family history of glaucoma or are of older age.

[Glaucoma and ocular hypertension in primary care]

OBJECTIVES

To find the distribution of intra-ocular pressure (IOP) in our population over 40 and the prevalence of glaucoma (G) and ocular hypertension (OH).

DESIGN

Descriptive.

SETTING

Primary care.

SUBJECTS

990 people >= 40 years old.Measurements. Age, sex, body mass index (BMI), ophthalmic history, risk factors, visual sharpness (optotype), ophthalmoscopy and IOP (applanation tonometry). Patients with back-of-eye disorders and/or IOP >= 21 mmHg were referred to the ophthalmologist for assessment (campimeter).

RESULTS

870 people, average age 54.66 and 45.4% of them men. Mean IOP was 12.96 in the right eye and 13.27 in the left, with significant differences between them, but not between sexes or age-groups. 70 patients were referred (11 for IOP >= 21, 54 for disturbance perceived by ophthalmoscope and 5 for both reasons). The ophthalmologist classified 9 as G, 12 as OH and 15 as suspected G. We calculated 1.81% (95% CI, 0.98-2.63) prevalence of G in the >= 40s, including 9 cases already known. OH prevalence was 1.61% (95% CI, 0.82-2.39). Through logistical regression, we found greater risk of G in people with myopia (OR adjusted for age and sex = 3.01) and Hypertriglyceridaemia (ORa, 6.34). OH risk was significantly greater in patients with BMI >= 30 (ORa, >= 4.20).

CONCLUSIONS

Glaucoma prevalence confirms published findings from other similar populations, while IOP and OH prevalence were much less here. Given that half G cases are undiagnosed, we believe its early detection in primary care should be highlighted, at least in at-risk groups.

Patterns of open-angle glaucoma in the Barbados Family Study

OBJECTIVE

To describe the Barbados Family Study of open-angle glaucoma (OAG) and present risk factors for OAG in siblings of study probands.

DESIGN

Observational study of families of probands with OAG.

PARTICIPANTS

Two hundred thirty probands and 1056 relatives (from 207 families).

METHODS

Probands and their family members underwent standardized examinations, including automated perimetry, applanation tonometry, ophthalmologic evaluation, fundus photography, blood pressure, interview, and genotyping. Generalized estimation equation methods were used to evaluate risk factors.

MAIN OUTCOME MEASURES

Presence of OAG in the relatives, as defined by both visual field and optic disc findings, after ophthalmologic exclusion of other causes.

RESULTS

The median ages of probands and relatives were 68 and 47 years, respectively. In the 207 families, 29% of the probands had one relative with OAG and 10% had two or more relatives affected. Of the 1056 family members, 10% had OAG, 13% had suspect OAG, and 6% had ocular hypertension. One fifth of the 338 siblings had OAG (n = 67); they tended to be older and more often were male. Multivariate comparisons between siblings with and without OAG found that age, higher intraocular pressure (IOP), myopia, and lower diastolic blood pressure-IOP differences were related to OAG, whereas hypertension and diabetes were not.

CONCLUSIONS

Based on standardized protocols and examinations, approximately one quarter of the relatives had OAG or suspected OAG, despite their relatively young age. Risk factors for OAG in siblings were similar to risk factors in unrelated individuals. Analyses are ongoing to determine OAG inheritance and to localize potential gene(s) involved.

High intraocular pressure and survival: the Framingham Studies

PURPOSE

To examine whether high intraocular pressure (greater than or equal to 25 mm Hg) or a history of treatment for glaucoma is associated with decreased survival and, if so, how such ocular markers might be explained.

METHODS

Eye examinations, including applanation tonometry, were conducted on members of the Framingham Eye Study cohort from February 1, 1973, to February 1, 1975. Participants who reported a history of treatment for glaucoma were identified. Survival data, including information on the date of death, were available from the time of the Eye Study through March 31, 1990.

RESULTS

Of the 1,764 persons under the age of 70 years at the baseline eye examination, 1,421 persons had low intraocular pressure (< or =20 mm Hg), 264 persons had medium intraocular pressure levels (20 to 24 mm Hg), and 79 persons had high intraocular pressure (> or =25 mm Hg) or history of glaucoma treatment. During the follow-up period, 29%, 30%, and 47% died in the groups with low, medium, and high intraocular pressure (or history of glaucoma treatment), respectively. In an age-and-sex adjusted Cox proportional hazards analysis, the death rate ratio for the group with medium intraocular pressure relative to the group with low intraocular pressure was 1.04. The corresponding death rate ratio for the group with high intraocular pressure was 1.56 with a 95% confidence interval of 1.11 to 2.19 (P < .001). After adjustment for age, sex, hypertension, diabetes, cigarette smoking, and body mass index, a positive relationship remained, but at a borderline level of significance (P = .075).

CONCLUSIONS

High intraocular pressure or the presence of glaucoma is a marker for decreased life expectancy in the Framingham Eye Study cohort. The relationship is present even after adjustment for risk factors known to be associated with higher mortality such as age, sex, hypertension, diabetes, cigarette smoking, and body mass index. Special attention to the general health status of patients with high intraocular pressure or glaucoma seems warranted.