Projected number of Australians with glaucoma in 2000 and 2030

Increased incidence of glaucoma medication usage in middle-aged Australian males taking antiretroviral medication - a population-based study

BACKGROUND

To investigate a possible association between glaucoma and the use of anti-retroviral therapy (ART) for HIV in the Australian population.

METHODS

A retrospective review of Australian Pharmaceutical Benefits Scheme data was undertaken from July 2012 to December 2016, inclusive. Three patient groups were compared: those on both topical intraocular pressure (IOP) -lowering medication and ART, those on ART only, and those on IOP-lowering medication only, using the 2016 Australian resident population to estimate prevalence. Odds ratios (95% confidence intervals, [CI]) with Fishers exact test for p values were calculated stratified by age and gender.

RESULTS

The number of prescriptions for topical glaucoma medications in the general Australian population increased progressively by age with a peak prevalence in those aged 80 years and above. Prevalence of ART was highest in males aged 40-49 and 50-59 years (0.41% [CI 0.40, 0.42] and 0.44% [CI 0.43, 0.45], respectively). Our analysis identified an increase in the prescription of IOP-lowering medication in males on ART aged 30-39 (OR 2.23 [CI 1.32, 3.75], p = 0.007) and 40-49 (OR 1.86 [CI 1.42, 2.43], p < 0.001), compared to those not on ART. There were no statistically significant increased odds for females or males aged 50 years or more.

CONCLUSION

Compared with the known increase in glaucoma prevalence with age in the general Australian population, a statistically significant increased prevalence in use of IOP-lowering medications was found in males on ART aged 30-49 years. The mechanism for this is yet to be determined, but possible causes include sequelae of HIV infection, a drug-induced side effect, or increased medical surveillance.

Lifetime Risk of Visual Impairment Resulting from Glaucoma in Patients Initially Followed up for Elevated Intraocular Pressure

PURPOSE

To report the lifetime risk of visual impairment resulting from glaucoma in patients originally followed up in a 10-year prospective randomized study initiated in 1981 to assess patients with elevated intraocular pressure (IOP).

DESIGN

Retrospective patient chart review.

PARTICIPANTS

Data on deceased patients who initially were followed up prospectively in the randomized controlled study and thereafter were followed up in ordinary clinical practice were collected until the end of 2017. Inclusion in the original study required an untreated IOP of 22 mmHg or more and 1 or more risk factors for glaucoma.

METHODS

Visual impairment, low vision, and blindness were defined according to the World Health Organization criteria. All eyes that became visually impaired were registered, including the date and cause of the impairment; the cumulative incidence of visual impairment corrected for competing risks was calculated; and the Kaplan-Meier method was used to analyze the importance of risk factors present at baseline for 1 eye per patient.

MAIN OUTCOME MEASURES

The proportion of patients who became bilaterally visually impaired because of glaucoma, the cumulative incidence of glaucoma-related visual impairment in at least 1 eye, and potential baseline risk factors for visual impairment caused by glaucoma.

RESULTS

Seventy-seven of 90 patients (86%) included in the initial randomized study were deceased at the end of 2017. Four patients were lost to follow-up during the clinical follow-up. Of the 77 patients, 7 (9%) became bilaterally visually impaired and 2 of those 7 became bilaterally blind because of glaucoma. The cumulative incidence of glaucoma-induced visual impairment in at least 1 eye increased from 0.00 after 5 years to 0.22 (95% confidence interval [CI], -0.01 to 0.67) after 30 years. The cumulative incidence of glaucoma blindness in at least 1 eye increased from 0.00 after 5 years to 0.17 (95% CI, 0.10-0.54) after 30 years. No specific risk factor significantly increased the risk of visual impairment caused by glaucoma.

CONCLUSIONS

Although the investigated patients showed elevated IOP and at least 1 additional glaucoma risk factor (i.e., they were high-risk patients), only a relatively small proportion of the patients with glaucoma demonstrated visual impairment.

The Projected Increase in Glaucoma Due to the Aging Population in Austria from 2001 to 2031: Results Based on Data of the Salzburg-Moorfields Collaborative Glaucoma Study

PURPOSE

The aim of this study is to present the projected increase in definite primary open angle glaucoma (POAG) and related diseases in Austria from 2001 to 2031.

METHODS

The present work is based on two data sources: population projections in Austria and detection rates of the Salzburg-Moorfields Collaborative Glaucoma Study for Austrians in the age groups 40-54 years, 55-69 years, and 70 years and above. The estimates of this glaucoma screening program are based on a total of 3419 subjects. Sensitivity analyses were applied to test the effects of higher and lower sets of prevalence assumptions on the extent of the probable projections.

RESULTS

The number of Austrians with definite POAG, early POAG, POAG suspects, and ocular hypertension (OHT) is expected to increase until 2031 by 0.5%, 43.1%, and 65.6% in the three age groups specified above, respectively. The overall number of Austrians with POAG at the age of 40 or older is estimated to increase from 67,600 in 2001 to 96,400 in 2031. This corresponds to an increase of 42% from 2001 to 2031 (lower scenario: 37%, upper scenario: 47%). Similar increases are expected for individuals with early POAG, POAG suspects, and OHT.

CONCLUSIONS

These projections provide an objective basis to estimate the resources that may be needed by health authorities and care providers such as ophthalmologists in the future and should help to design glaucoma blindness prevention programs or screening studies in Austria. The predicted continuous increase of Europe's older population will prove to become a challenge for public health professionals not only for diagnosis and monitoring, but also for the treatment of glaucoma.

Reduced health-related quality of life among Japanese college students with visual impairment

Background

Although previous studies have shown detrimental effects of visual impairment on health-related quality of life (HRQOL), they were primarily conducted on elderly individuals with visual impairment. The objective of this cross-sectional study was to investigate if HRQOL is impaired in young college students with visual impairment and to explore the relationships between HRQOL and other factors. It was hypothesized that visual impairment is not influential enough to lower the HRQOL of young people due to their better physical fitness and more flexible mentality.

Methods

A total of 21 college students (mean age = 25 years old) with varying degrees of visual impairment completed the short form (SF)-36 health survey and questionnaires on daily physical activities. Subjects were grouped depending on the type of visual impairment: blind (n = 11) or severely impaired (n = 10). In addition, grip strength and single-leg standing balance were assessed.

Results

No between-group differences were found in the SF-36 scores. However, compared to the general Japanese standards (50.0 ± 10.0), the Vitality scores of the blind group were lower (41.9 ± 7.2, p = 0.004) and the Physical Function scores of the severely impaired group were higher (55.3 ± 2.4, p = 0.001). In addition, a negative correlation was found between standing balance (variability of foot center of pressure) and the Physical Component Summary score of the SF-36 (r² = 0.35, p = 0.005).

Conclusions

These findings suggest that even among young people severe visual impairment leads to reductions in some components of HRQOL.

Retinal vessel caliber is associated with the 10-year incidence of glaucoma: the Blue Mountains Eye Study

PURPOSE

To examine associations between quantitatively measured retinal vessel caliber and the 10-year incidence of primary open-angle glaucoma (OAG).

DESIGN

Population-based cohort study.

PARTICIPANTS

The Blue Mountains Eye Study examined 3654 persons at baseline and 2461 persons at either 5 years, 10 years, or both times. After excluding 44 subjects with OAG at baseline, 2417 participants at risk of OAG at the 5- or 10-year examinations were included.

METHODS

Retinal vessel calibers of baseline retinal photographs were measured using a computer-based program and summarized as central retinal artery and vein equivalents (CRAE, CRVE). Incident OAG was defined as the development of typical glaucomatous visual field loss combined with matching optic disc rim thinning and an enlarged cup-to-disc (C:D) ratio of >0.7 or C:D asymmetry between the 2 eyes (≥0.3) at either the 5- or 10-year examination. Generalized estimating equation models were used to account for correlation between eyes while adjusting for glaucoma risk characteristics including intraocular pressure (IOP) or ocular perfusion pressure (OPP).

MAIN OUTCOME MEASURES

We assessed the 10-year incidence of OAG.

RESULTS

There were 82 persons (104 eyes) who developed incident OAG over the 10-year follow-up. After adjusting for age, sex, family history of glaucoma, smoking, diabetes, hypertension, hypercholesterolemia, body mass index, spherical equivalent refraction, and C:D ratio, narrower CRAE was associated with higher risk of incident OAG (adjusted odds ratio [OR], 1.77; 95% confidence interval [CI], 1.12-2.79, per standard deviation decrease in CRAE). This association persisted after further adjustment for IOP (adjusted OR, 1.87; 95% CI, 1.14-3.05) or OPP (adjusted OR, 1.76; 95% CI, 1.11-2.78), and remained significant when analyses were confined to eyes with IOP<20 mmHg and C:D ratio<0.6 at baseline. There were no independent associations between CRVE and incident OAG.

CONCLUSIONS

Retinal arteriolar narrowing, quantitatively measured from retinal photographs, was associated with long-term risk of OAG. These data support the concept that early vascular changes are involved in the pathogenesis of OAG and suggest that computer-based measurements of retinal vessel caliber may be useful to identify people with an increased risk of developing the clinical stage of glaucoma.

FINANCIAL DISCLOSURE(S)

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

Co-prescribing of topical and systemic beta-blockers in patients with glaucoma: a quality use of medicine issue in Australian practice

PURPOSE

Prescribing topical beta-blockers for patients with glaucoma, who are also being treated with systemic beta-blockers, raises efficacy and safety concerns. This potentially inappropriate co-prescribing practice is a Quality Use of Medicine issue. This study aimed to quantify the extent of co-prescribing of topical and systemic beta-blockers in Australian clinical practice.

METHODS

This is a retrospective analysis of de-identified billing data for supply (surrogate marker for prescribing) of topical and systemic beta-blockers from the Pharmaceutical Benefits Scheme (1999-2004) to concessional patients supplied either topical or systemic beta-blockers. The primary outcome was the percentage of patients supplied systemic beta-blockers within the patient population supplied topical beta-blockers. This percentage was calculated for each financial year (July 1999-June 2004), age group (<65 years; 65-74 years; 75-84 years; > or =85 years) and sex.

RESULTS

Approximately 20% of patients supplied topical beta-blockers (representing Australian glaucoma patients) were also supplied systemic beta-blockers, equating to more than 20 000 patients per year. This percentage varied with age, but not with year or sex. The percentage of patients co-supplied topical and systemic beta-blockers was the lowest (13%) for patients <65 years and the highest (23%) for patients 75-84 years.

CONCLUSIONS

Pharmaceutical Benefits Scheme supply data shows that the potentially inappropriate practice of co-prescribing topical and systemic beta-blockers affects more than 20 000 concessional patients in Australia each year, particularly the elderly. This Quality Use of Medicine issue has now been quantified; doctors, pharmacists and patients must be made aware of the reduced efficacy and potential for more side-effects from this co-prescribing practice.

Self-reported glaucoma in Canada: findings from population-based surveys, 1994-2003

BACKGROUND

To provide population estimates and 10-year trends in the self-reported prevalence of glaucoma in Canada, including age and sex profiles, frequency of contact with eye specialists, and associated chronic medical conditions.

METHODS

Analyses were based on cross-sectional, self-reported data for ages >or=20 years from 5 national surveys: the 1994-95, 1996-97, and 1998-99 National Population Health Survey (minimum sample size [n] = 33 153) and the 2000-01 and 2002-03 Canadian Community Health Survey (min n = 113 212). Prevalence estimates were derived from descriptive analyses; multivariate logistic regression analyses examined the association of income, education, and chronic medical conditions with the likelihood of reporting glaucoma.

RESULTS

In 2002-03, an estimated 409,000 Canadians had glaucoma, including 2.7% of those >or=40 years and 11% of those >or=80 years. Overall, the prevalence of self-reported glaucoma increased from 1.1% in 1994-95 to 1.8% in 2002-03 (p < 0.01). Significant increases in age-specific prevalences over time were also observed in 4 of 6 age groups. In total, 14% of respondents with glaucoma reported no recent contact with an eye specialist. Arthritis (and other rheumatic conditions), high blood pressure, migraines, and diabetes were associated with glaucoma.

INTERPRETATION

Our review suggests glaucoma is at least as prevalent in Canada as in other Western nations. It is most common in the over-80 age group and appears to be associated with other medical conditions.

Treating ocular hypertension to reduce glaucoma risk: when to treat?

When to treat the patient who presents with ocular hypertension has been a question that has 'stumped' the ophthalmic community for decades. Population-based studies and intervention trials have provided the basis for understanding why we consider treating such patients. Although the EGPS (European Glaucoma Prevention Study) did not demonstrate that reducing intraocular pressure (IOP) with dorzolamide prevented the onset of glaucoma compared with individuals receiving a placebo, the investigators of the OHTS (Ocular Hypertension Treatment Study) found that the treatment of ocular hypertension can be delayed with topical medication when treated patients were compared with an observation group. There are differences in inclusion criteria, study design and retention rates between the EGPS and the OHTS, which may have led to the discrepancies in outcomes between these two studies. These differences provide a basis for understanding the relevance of the findings of both trials to clinical practice. The clinician should consider key risk factors such as age, thin corneal thickness measurements, large cup-to-disc ratio and mean IOP when determining who should be treated. However, the ultimate decision of when to treat will be determined by other issues such as life expectancy, the general health of the patient and the number of risk factors. Clearly, the treatment of only high-risk patients with ocular hypertension should be considered.

Glaucoma treatment in Australia: changing patterns of therapy 1994-2003

AIM

To document the change in pattern of glaucoma treatment in Australia over the decade 1994-2003.

METHODS

Observational study: retrospective data audit.

RESULTS

The total number of prescriptions for glaucoma items has increased in this time period from 1.9 million to 3.3 million, with a cost increase to the Pharmaceutical Benefits Scheme (PBS) of in excess of 50m dollars. The largest increase has been in the class of prostaglandin analogues, which now comprise 49% of all glaucoma topical therapy prescriptions. Rates of laser trabeculoplasty and trabeculectomy surgery have fallen by 60% and 58%, respectively. Rates for secondary procedures such as repeat trabeculectomy, drainage implant devices and cycloablation have remained stable, although with some variation between Australian states.

CONCLUSIONS

The introduction of multiple new medications has resulted in a decline in the amount of glaucoma surgery and laser trabeculoplasty performed. There has been an associated increase in the total number of glaucoma prescription items dispensed, and a large increase in the cost to the PBS of this change. Outcome measures of the benefit of these changes are lacking.

Role of oxidative stress enzymes in open-angle glaucoma

PURPOSE

To investigate the role of oxidative stress and lipid peroxidation in the pathogenesis of primary open-angle glaucoma (POAG).

MATERIALS AND METHODS

The activities of myeloperoxidase (MPO), catalase (CAT), and the levels of plasma malondialdehyde (MDA) were measured in 40 (15 men and 25 women) patients with POAG and 60 (30 men and 30 women) healthy controls.

RESULTS

There was no significant difference in the activities of CAT and MPO between the POAG patients and the controls. However, the plasma MDA level was significantly higher in patients than the controls.

CONCLUSION

The results of this preliminary study suggest that the possible alterations of plasma MDA levels may be associated with the pathogenesis of POAG, but further research is needed to understand the role of oxidative damage in this important disorder of aging.

The projected increase in glaucoma due to an ageing population

The number of cases of primary open angle glaucoma (POAG) in England and Wales is estimated to increase by a third over the 20 years to 2021, and then continue upwards at a similar pace to 2031. The estimates are based on official population projections, organised by 5-year age groups, together with an age-specific prevalence curve for POAG derived from the results of 11 epidemiological prevalence surveys. To cope with additional pressures, a thorough reappraisal of the present system for detection, referral, diagnosis, treatment and monitoring of the disease is likely to be required.

Primary open-angle glaucoma

Early diagnosis of this otherwise progressive, asymptomatic process is essential.

Relationship between age and intraocular pressure: the Blue Mountains Eye Study

This study aimed to assess the influence of age on intraocular pressure(IOP) in a general population. The Blue Mountains Eye Study assessed 3654 residents aged 49+ years during 1992-1994. Intraocular pressure was measured using Goldmann applanation tonometry. Subjects with glaucoma, those currently on glaucoma medications and those with a history of cataract surgery were excluded. The IOP was reliably measured in 3260 subjects. Mean IOP was 16.0 mmHg with no significant difference found between men and women (P < 0.89). In univariate analyses, age was positively associated with IOP (P < 0.05). Systolic blood pressure (SBP) was strongly positively associated with IOP (P < 0.001). After adjusting for SBP, there was a trend for IOP to decrease with increasing age(P < 0.051). After further adjusting for other potential confounders (diabetes, glaucoma family history and myopia), age was no longer significantly associated with intraocular pressure (P < 0.29). In summary,no evidence was found of an independent age affect on IOP.