Comparison of newly diagnosed ocular hypertension and open-angle glaucoma: ocular variables, risk factors, and disease severity

Evolution of first-line glaucoma therapy, 2007-2018: a population-based analysis

OBJECTIVE

To evaluate the long-term evolution of first-line glaucoma therapy (FLGT) initiated by ophthalmologists and optometrists.

DESIGN

Retrospective population-based study using validated provincial health care databases.

PARTICIPANTS

194,759 Ontario residents, 66 years of age or older, who received FLGT between 2007 and 2018.

METHODS

A total of 194,759 individuals from 12 annual cohorts were enrolled, and rates of first-line medical treatment (prostaglandin analogue [PGA], beta-blocker, alpha-2-agonist, and carbonic anhydrase inhibitor) and laser trabeculoplasty (LT) were calculated. Provider (ophthalmologist or optometrist) rates also were assessed.

RESULTS

Across the entire study period, of the 194,759 enrolled individuals who received FLGT, 60.2% initially received medical treatment and 39.8% underwent LT. Approximately 94.6% were treated by ophthalmologists. PGA therapy was the most common therapy prior to 2010, whereupon LT became the most common FLGT. By 2015, LT exceeded the total of all medications as FLGT. The annual rate of initial medication prescriptions by optometrists rose to 101.4 per 100,000 population between 2011 and 2018. In 2018, PGA and non-PGA prescription rates by ophthalmologists were 2.6 and 5.0 times higher, respectively, than prescription rates by optometrists.

CONCLUSION

LT therapy has become the most common FLGT for Ontario residents 66 years of age or older. PGAs remain the most frequently prescribed glaucoma medication. While ophthalmologists continue to provide the majority of FLGT, optometrists now provide a small but growing fraction of FLGT following the introduction of glaucoma medication prescribing privileges.

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.

Impact of discontinuing government-funded routine eye exams on new glaucoma diagnoses in Ontario

OBJECTIVE

In 2004, government-funded routine eye exams were discontinued for individuals aged 20-64 years in Ontario. We assessed whether this policy change reduced the rate of new glaucoma diagnoses.

DESIGN

Cohort-based time-series analysis.

PARTICIPANTS

Ontarians aged 20+ years in 2000-2014.

METHODS

Province-wide physician billing data were analyzed using segmented regression analysis. New glaucoma diagnoses were defined as the first glaucoma diagnostic billing code submitted by an ophthalmologist or optometrist among Ontarians who did not visit an ophthalmologist or an optometrist in the year prior to the study year.

RESULTS

Before versus after 2004, the rate of new glaucoma billings was reduced in all age groups: -2.7% (p < 0.0001) in the age group 20-39 years, -8.2% (p < 0.0001) in the age group 40-64 years (p < 0.0001), and -2.1% (p = 0.0003) in the age group 65+ years. This corresponds to a decreased number of individuals with a new glaucoma billing after 2004 versus before 2004: -8,800 (p < 0.001) in the age group 20-39 years, -32,234 (p < 0.0001) in the age group 40-64 years, and -3,255 (p = 0.0012) in the age group 65+ years. Reduced rates of new glaucoma diagnostic billings were seen in males, females and rural and urban residents among policy-affected and policy-unaffected age groups. Ontarians living in the wealthiest neighbourhood areas also had a significantly reduced rate after versus before 2004: -2.7% (p < 0.0001) for the age group 20-39 years, -9.0% (p < 0.0001) for the age group 40-64 years, and -2.3 % (p < 0.001) for the age group 65+ years.

CONCLUSIONS

Discontinuation of government-funding for routine eye exams was associated with a significantly reduced rate of new glaucoma diagnostic billings irrespective of sociodemographics. More research is needed to understand the reduced glaucoma billings in unaffected seniors and those living in the wealthiest neighbourhood areas.

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.

Cigarette smoking and glaucoma in the United States population

PurposeTo evaluate the association between cigarette smoking and glaucoma in the United States population.Patients and methodsUS civilian, non-institutionalized population from 2005 to 2008 administrations of the National Health and Nutrition Examination Survey that were ≥40 years of age with visual fields and optic disc photographs were included. Diagnosis of glaucoma was based on the Rotterdam criteria. Logistic regression modeling was performed to assess the association between glaucoma and smoking history, while controlling for age, gender, ethnicity, household income, alcohol consumption, diabetes, and hypertension.ResultsIn 3864 participants, 212 (5.5%) had glaucoma (corresponds to a population weighted glaucoma prevalence of 3.7% in a total of 83 570 127 subjects). Population weighted proportion of current smokers was 20.6% and ex-smokers was 28.3%. Participants with glaucoma were older (63.0±11.6 vs 56.1±11.2, P=0.002), likely to be male (57.1% vs 49.2%, P=0.03), to be Black (36.3% vs 20.7%, P<0.001), and to have diabetes (18.9% vs 12.4%, P=0.006) and hypertension (50.5% vs 39.7%, P=0.003). Current smokers had a lower odds of glaucoma compared to non-smokers (OR=0.61, 95% CI=0.41-0.88, P=0.009), and ex-smokers (OR=0.46, 95% CI=0.28-0.76, P=0.002). The effect estimates were similar in adjusted models, but not statistically significant. Among smokers, greater pack/day of smoking history was associated with statistically significantly higher odds of glaucoma (OR=1.70, 95% CI=1.08-2.67, P=0.02).ConclusionsAmong cigarette smokers, heavy smoking defined by greater number of pack of cigarettes smoked per day is associated with higher odds of glaucoma. Health care providers should include this association when counseling patients on their smoking habit.

The association between cigarette smoking and primary open-angle glaucoma: a systematic review

Glaucoma is one of the most common causes of irreversible blindness, globally. Findings from the Blue Mountain Eye Study suggest a moderate positive association between smoking and increased IOP (a significant risk factor for glaucoma). The previous two reviews investigating the association between smoking and primary open-angle glaucoma (POAG) show inconsistent findings and do not include recent studies investigating the dose-response effect of smoking. The current study aims to conduct an up-to-date, comprehensive evaluation of the existing literature. Identification of relevant existing literature was performed by an online search in MEDLINE for studies published from 1st January 1946 to 5th February 2015. The MESH headings (keywords) included "open-angle glaucoma" and "cigarette" or "smoking" or "tobacco". Two independent reviewers assessed the eligibility of each report based on predefined inclusion criteria. Odds ratios and 95 % confidence intervals (95 % CIs) were obtained from studies, for the change in risk of glaucoma due to both past and current smoking. Of the 26 abstracts reviewed, 17 papers were included in the final analysis. Nine of these were case-control studies, five cohort studies and three cross-sectional in design. Six of the case-control studies found a positive association between smoking and POAG, unlike the remaining studies. However, two relatively recent, large studies (including one prospective cohort study) investigating the effect of smoking dose have found a significant increase in risk of POAG in very heavy smokers. There is limited evidence for a causal association between tobacco smoking and POAG. The evidence for a link between current smoking and POAG appears stronger than that of past smoking, but recent studies suggest that heavy smoking may increase the risk of POAG. Future studies must further investigate the possible positive association between heavy smoking and POAG by stratifying participants by pack years and age.

Short-Term Moderately Elevated Intraocular Pressure Is Associated With Elevated Scotopic Electroretinogram Responses

Purpose

Moderately elevated intraocular pressure (IOP) is a risk factor for open-angle glaucoma. Some patients suffer glaucoma despite clinically measured normal IOPs. Fluctuations in IOP may have a significant role since IOPs are higher during sleep and inversion activities. Controlled transient elevations of IOPs in rats over time lead to optic nerve structural changes that are similar to the early changes observed in constant chronic models of glaucoma. Because early intervention decreases glaucoma progression, this study was done to determine if early physiological changes to the retina could be detected with noninvasive electrophysiological and optical imaging tests during moderately elevated IOP.

Methods

Intraocular pressures were raised to moderately high levels (35 mm Hg) in one eye of Sprague-Dawley rats while the other (control) eye was untreated. One group of rats underwent scotopic threshold response (STR) and electroretinogram (ERG) testing, while another 3 groups underwent optical coherence tomography (OCT) imaging, Western blot, or histologic evaluation.

Results

The amplitudes of the STR and ERG responses in eyes with moderately elevated IOPs were enhanced compared to the values before IOP elevation, and compared to untreated contralateral eyes. Structural changes to the optic nerve also occurred during IOP elevation.

Conclusions

Although ischemic IOP elevations are well-known to globally reduce components of the scotopic ERG, acute elevation in rats to levels often observed in untreated glaucoma patients caused an increase in these parameters. Further exploration of these phenomena may be helpful in better understanding the mechanisms mediating early retinal changes during fluctuating or chronically elevated IOP.

A Randomised Open Label Comparative Clinical Trial on the Efficacy of Latanoprost and Timolol in Primary Open Angle Glaucoma

INTRODUCTION

Timolol, a beta blocker, is the most commonly prescribed first line therapy in the treatment of primary open angle glaucoma. Latanoprost, a prostaglandin analogue, is a novel drug in glaucoma therapy. Its efficacy has to be proved for it to be included under the first line therapy in the treatment of primary open angle glaucoma.

AIM

To compare the efficacy of Latanoprost with that of Timolol in the treatment of primary open angle glaucoma (POAG).

MATERIALS AND METHODS

In this study the enrolled patients were randomly divided into two groups by block randomization. The sample size was determined to be 60 in each group. One group received 0.005% of Latanoprost once daily in the evening and the other group 0.5% of Timolol twice daily. The efficacy was measured in terms of intraocular pressure at scheduled follow up visits.

RESULTS

At the start of the study, intraocular pressures of both groups were comparable. At the end point, reduction of intraocular pressure among Latanoprost group was significantly greater than that of Timolol group (9.72 vs 7.27, p = 0.002).

CONCLUSION

Latanoprost was found to be superior to Timolol in reducing the intraocular pressure in treatment of patients with primary open angle glaucoma.

Socioeconomic status as a risk factor for late presentation of glaucoma in Canada

OBJECTIVE

To evaluate the effect of socioeconomic status on late presentation of glaucoma.

DESIGN

Prospective, multicentre, cross-sectional study.

PARTICIPANTS

Newly diagnosed open-angle glaucoma.

METHODS

Eligible subjects with newly diagnosed open-angle glaucoma underwent a comprehensive ocular examination and were classified as mild, moderate, or advanced according to the Canadian Ophthalmological Society glaucoma guidelines. Socioeconomic status was estimated by linking the subjects' postal code to the median household income in the 2006 Canadian population census at the level of dissemination areas. Five equal income groups ranging from the lowest to the highest income quintile were considered and compared regarding the frequency and proportion of moderate or advanced glaucoma.

RESULTS

A total of 290 subjects were included in the analysis; 151 (52.1%) had mild, 79 (26.9%) moderate, and 60 (21.0%) advanced disease at initial diagnosis. Patients with newly diagnosed glaucoma were less likely to come from the poorest neighborhood areas (16.21%) when compared with an expected one fifth (20%) of patients presented in each of the 5 social economic groups (P = 0.56). Compared with people from the poorest neighborhood areas, people from the richest neighborhood areas had a marginally lower risk for having moderate or advanced glaucoma at first presentation (prevalence ratio 0.66, 95% confidence interval: 0.43-1.02, P = 0.06). This association was stronger among those ≥65 years old (P = 0.006).

CONCLUSIONS

To the best of our knowledge, this is the first study in Canada to provide evidence that socioeconomic deprivation is associated with greater severity of glaucoma at presentation, specifically for those ≥65 years old. Consideration should be given to targeting poor neighborhood areas for glaucoma education, screening, or both.

De-insurance in Ontario has reduced use of eye care services by the socially disadvantaged

OBJECTIVE

Effective November 1, 2004, the Ontario Ministry of Health and Long-Term Care de-insured, or delisted, routine eye examinations for Ontarians aged 20 to 64 years. We examined whether this delisting reduced Ontarians' access to eye care providers (ophthalmologists and optometrists).

DESIGN

Cross-sectional survey.

PARTICIPANTS

Ontario respondents to the Canadian Community Health Survey in 2000/2001 (n = 39 234 before delisting) and 2007/2008 (n = 43 835 after delisting).

METHODS

We compared utilization rates of eye care providers by Ontarians in a 12-month period in 2000/2001 to utilization rates in 2007/2008 using self-reported data.

RESULTS

Among Ontarians aged 40 to 64 years, utilization was significantly reduced (-7.2%, p < 0.05) after delisting by those who did not have a secondary school graduation certificate. This was compared to a slight reduction (-0.7%, p > 0.05) by those who had completed secondary school or higher education. A reduction of -5.4% was observed among Ontarians in the lowest income quintile in contrast to increased utilization in all other income groups (p > 0.05). Before delisting, the gap in utilization between people with and without a secondary school graduation certificate was 4.7%. This gap doubled to 11.2% after delisting (p < 0.05). The disparity in utilization between those in the highest and lowest income quintile was 4.5% before delisting and 12.0% after delisting (p > 0.05). Cost was the likely barrier that resulted in this finding.

CONCLUSIONS

The use of eye care providers among socially disadvantaged Ontarians decreased significantly after vision care services were delisted. The effects of delisting appear to have caused an inequity in access to eye care providers, and that contradicts the objectives of the Canada Health Act.