Assessment of the iCare HOME2, a New Intraocular Pressure Self-Measurement Tonometer.

PRCIS: The iCare HOME2 tonometer generally can be considered reliable for most eyes and clinical settings, although it may produce slightly overestimated or underestimated intraocular pressure (IOP) readings in thicker and thinner corneas, respectively. PURPOSE: To evaluate the accuracy, correlation, and analysis of differences in IOP measurements between the gold standard Goldmann applanation tonometer (GAT) and the new, self-measurement iCare HOME2 tonometer (icare). PATIENTS AND METHODS: In this retrospective study, patients were randomly selected from those who attended a routine examination in our clinic. After a complete ocular examination, each patient's IOP was measured and recorded with GAT and iCare HOME2. Central corneal thickness was measured. Eyes with any corneal morbidity were excluded. Pearson correlation coefficient was used to determine the correlation between paired IOP measurements. Bland-Altman plots were graphed for the analysis of differences in IOP between the instruments. RESULTS: One hundred thirty-five eyes of 70 patients were included in the study. The mean IOP measured with GAT was 16.3 ± 6.5 mm Hg (range: 3-56). The mean IOP measured with iCare HOME2 was 16.5 ± 7.3 mm Hg (range: 3-55), ( P = 0.47). A strong, significant positive correlation was found for paired IOP measurements by the 2 instruments ( r = 0.94; P < 0.0001). A small systematic proportional bias was seen for the paired IOP measurements, meaning that with higher IOPs the iCare HOME2 yielded higher IOP readings than GAT, but this difference was clinically insignificant. The instrument underestimated IOPs with corneas thinner than 522 µm, whereas it overestimated IOPs when corneas were thicker than this. CONCLUSION: The iCare HOME2 could be a reliable tonometer for most eyes and clinical settings. Central corneal thickness measurement is recommended in patients who use the instrument.

Activity Limitation in Glaucoma: Objective Assessment by the Cambridge Glaucoma Visual Function Test.

PURPOSE: We design and evaluate a computer-based objective simulation of activity limitation related to glaucoma. METHODS: A cross-sectional study was performed involving 70 glaucoma patients and 14 controls. Mean age was 69.0 ± 10.2 years; 49 (58.3%) were male. The Cambridge Glaucoma Visual Function Test (CGVFT) was administered to all participants. Rasch analysis and criterion, convergent, and divergent validity tests assessed the psychometric properties of the CGVFT. Regression modeling was used to determine factors predictive of CGVFT person measures. Sociodemographic information, better and worse eye visual field parameters, visual acuity, contrast sensitivity, and the Rasch-analyzed Glaucoma Activity Limitation-9 (GAL-9) and Visual Function Questionnaire Utility Index (VFQUI) questionnaire responses were recorded. RESULTS: From 139 pilot CGVFT items, 59 had acceptable fit to the Rasch model, with acceptable precision (person separation index, 2.13) and targeting. Cambridge Glaucoma Visual Function Test person measure (logit) scores increased between controls (-0.20 ± 0.08) and patients with mild (-0.15 ± 0.08), moderate (-0.13 ± 0.10), and severe (-0.05 ± 0.10) glaucoma (P < 0.001, ANOVA) indicating good criterion validity. Correlation coefficients of 0.455 (P < 0.001) between CGVFT and GAL-9 person measures and 0.399 (P = 0.005) between CGVFT and VFQUI person measures demonstrated convergent validity. Divergent validity was suboptimal. On multivariable analysis, lower better eye mean deviation and greater age were associated with worsening CGVFT person measures (P ≤ 0.001). CONCLUSIONS: The CGVFT is a computerized visual challenge test administered to a cohort of glaucoma patients. It may benefit glaucoma patients, careers, health care providers, and policy makers, providing increased awareness of activity limitation due to glaucoma.

Comparing the effectiveness of selective laser trabeculoplasty with topical medication as initial treatment (the Glaucoma Initial Treatment Study): study protocol for a randomised controlled trial.

BACKGROUND: Glaucoma is the leading cause of irreversible blindness in the world. Estimated to affect 60 million people worldwide, this figure is expected to rise to 80 million by 2020. Untreated, glaucoma leads to visual decay and eventually to blindness, and can significantly reduce quality of life. First-line treatment in patients with primary open-angle glaucoma and exfoliative glaucoma is topical medical therapy with ocular hypotensives as eye drops. However, eye drops have several disadvantages including cost, possible local and systemic side effects, and adherence and perseverance issues. Randomised controlled trials have demonstrated that selective laser trabeculoplasty is equally as effective in lowering intraocular pressure as eye drops. However, the impact of these two treatment modalities from the patient and economic perspectives has not been adequately determined. Thus, it remains unclear whether topical medical therapy or selective laser trabeculoplasty should be recommended as first-line treatment for glaucoma. METHODS/DESIGN: This protocol describes an international, multi-centre, randomised controlled trial to determine the optimum first-line therapy for people with primary open-angle glaucoma and exfoliative glaucoma. This study will compare the effect of selective laser trabeculoplasty and topical medication with respect to patients' generic and glaucoma-specific quality of life. The trial will also provide a detailed cost-effectiveness analysis and compare the clinical effectiveness with respect to the degree of intraocular pressure lowering and rates of treatment failure. Research coordinators in each centre will identify and recruit previously untreated patients with primary open-angle glaucoma and exfoliative glaucoma. Those who meet the eligibility criteria will be invited to enter a randomised controlled trial with either selective laser trabeculoplasty or topical ocular hypotensive therapy, according to a stepped regimen. Outcome assessment will be measured at 6 weeks and at 6, 12, and 24 months post-treatment. Regular clinic follow-ups will continue as clinically indicated between study outcome visits. DISCUSSION: The Glaucoma Initial Treatment Study is the first multi-centred RCT to determine the optimum first-line therapy for people with glaucoma. Our trial will have an unprecedented capacity to meaningfully transform the treatment and management of glaucoma in Australia and overseas. TRIAL REGISTRATION: ACTRN12611000720910; Date registered: 11 July 2011.

Optic nerve head assessment: comparison of Cirrus optic coherence tomography and Heidelberg Retinal Tomograph 3.

BACKGROUND: The purpose of this study was to analyse the relationship between optic nerve head (ONH) parameters measured by spectral domain optical coherence tomography and confocal scanning laser ophthalmoscope. DESIGN: Prospective, cross-sectional study. Hospital setting. PARTICIPANTS: One hundred seventy-three subjects (85 glaucoma and 88 normal subjects). METHODS: One eye from each individual was selected randomly for ONH imaging by the spectral domain Cirrus OCT and Heidelberg Retinal Tomograph 3 (HRT3). MAIN OUTCOME MEASURES: Four ONH parameters that are measured by both technologies (average cup-to-disc ratio [CDR], rim area, disc area and cup volume) were analysed and compared for differences, agreement of the categorical classification, diagnostic sensitivities and specificities and the area under the receiver operating characteristic curves (AUC). RESULTS: ONH parameters, as determined by the two technologies were significantly different but strongly correlated. Proportional bias was demonstrated for all measurements. The agreement of categorical classification was excellent for CDR (κ = 0.94) and good for rim area and cup volume (κ = 0.63 and 0.71, respectively). The highest sensitivities at fixed specificities were achieved by Cirrus OCT. AUCs for CDR, rim area, disc area and cup volume were not significantly different between the two technologies. CONCLUSIONS: The diagnostic capability of ONH measurements by both technologies is similar. Paired ONH measurements by Cirrus OCT and HRT3 are strongly correlated but significantly different and proportionally biased. The results preclude interchangeable use of the absolute values, but categorical classification of ONH parameters may be interchangeable in clinical practice.

An assessment of the health and economic burdens of glaucoma.

PURPOSE: To bring together information concerning the epidemiology and the economic and individual burdens of glaucoma. DESIGN: Interpretive essay. METHODS: Review and synthesis of selected literature published from 1991 through December 2010. RESULTS: An estimated 3% of the global population over 40 years of age currently has glaucoma, the majority of whom are undiagnosed. Vision loss from glaucoma has a significant impact on health-related quality of life even in the early stages of disease. The overall burden increases as glaucomatous damage and vision loss progress. The economic burden of glaucoma is significant and increases as the disease worsens. CONCLUSIONS: Early identification and treatment of patients with glaucoma and those with ocular hypertension at high risk of developing vision loss are likely to reduce an individual's loss of health-related quality of life as well as the personal and societal economic burdens.

Towards integrated care: Australia's new model of care for patients with glaucoma.

Using shared care to tackle the complexity of optimal patient management.

Use of glaucoma medications: state of the science and directions for observational research.

PURPOSE: To summarize observational studies that focus on the use of glaucoma medications and to identify gaps in knowledge to guide future investigation. DESIGN: Literature study. METHODS: We searched the electronic databases MEDLINE, EMBASE, and PubMed for English language articles published through December 2009 using the search terms physician's practice patterns, drug prescriptions, pharmaceutical services, medication adherence, ophthalmology, glaucoma, and ophthalmic solutions. We categorized studies by areas of focus and extracted and summarized key features: study population, data sources, and main findings. RESULTS: We identified 2224 articles by the search. Fifty-five described glaucoma medication use using large databases. Predominant areas of focus were: trends in prescription choices (n = 13); adherence, persistence, or both (n = 31); rational use of medications (n = 9); and policy-related issues (n = 2). Over the last decade, use of ß-blockers and miotics has decreased substantially, whereas new agents, particularly prostaglandin analogs, have become more popular. Nonadherence was an issue in more than 25% of patients. A significant proportion of patients with comorbidities, contraindications, or both had received topical ß-blockers. CONCLUSIONS: To date, most studies have focused on adherence to glaucoma medications and changes in treatment choices. Major gaps in knowledge include prescribing patterns by prescriber specialty (ophthalmologists, primary care physicians, and optometrists), medication-related problems, and subsequent adverse health outcomes. Well-designed longitudinal observational studies addressing these gaps are warranted to improve patient safety.

Depression and quality of life in patients with glaucoma: a cross-sectional analysis using the Geriatric Depression Scale-15, assessment of function related to vision, and the Glaucoma Quality of Life-15.

PURPOSE: To determine the prevalence of depression and its association with visual field impairment, quality of life, objective assessment of visual function, and glaucoma severity in elderly patients with glaucoma. DESIGN: Cross-sectional study. PARTICIPANTS AND CONTROLS: One hundred sixty-five patients with mild (n=60), moderate (n=43), or severe (n=28) glaucoma and 34 controls with ocular hypertension were enrolled. Severity was stratified according to the Nelson Glaucoma Severity Scale (based on the degree of binocular visual field loss). Groups were substratified according to age. METHODS: Demographic information was collected via interviews; the Geriatric Depression Scale-15 and Glaucoma Quality of Life-15 (GQL-15) questionnaires were administered. Visual function was assessed by clinical examination and visual field testing. A subset of patients (n=68) underwent objective assessment of function related to vision. Group differences were evaluated using analysis of variance; Kruskall-Wallis analysis of ranks was performed with significance set at P<0.05. Age-adjustment of P values was performed using analysis of covariance for parametric data and Kruskall-Wallis analysis on age-stratified nonparametric data. A binary univariate regression analysis modeled depression to suspected risk factors. Significant predictive variables were modeled in a multivariate regression analysis. RESULTS: Depression was more prevalent with increasing glaucoma severity, reaching statistical significance in patients aged 70 to 79 years (P<0.02). Summary and subfactor GQL-15 scores reflected decreased quality of life with increasing glaucoma severity. Assessment of function related to vision scores indicated worsening visual function with increasing glaucoma severity. On multivariate regression analysis, depression status was correlated with age and GQL-15 summary score. CONCLUSIONS: Depression is more common in patients with increasing glaucoma severity (age, 70 to 79 y). In patients with glaucoma or ocular hypertension, age and GQL-15 summary score are independent risk factors for depression.

Is this neuroprotective drug good for my glaucoma patients? Some key factors in clinical decision-making.

Neuroprotection protects neurons from death after a primary insult, independent of that insult. Important clinical considerations include minimal interference with physiological processes, possible simultaneous or sequential treatment strategies, and most effective method of drug delivery. Clinicians' assessment of the neuroprotective value of any agent hinges on demonstration of efficacy by prospective randomized controlled trials. Use of a neuroprotectant will depend on the glaucomatous threat to a patient's visual function, as well as the agent's therapeutic index and its cost.

Glaucoma prescribing trends in Australia and New Zealand.

PURPOSE: To summarize current practice styles and patterns associated with glaucoma management in ophthalmologists of Australia and New Zealand as derived from a survey. METHOD: A questionnaire was sent to all Australian and New Zealand ophthalmologists, which anonymously assessed demographic characteristics and prescribing patterns for each major class of glaucoma medication. RESULTS: A total of 761 questionnaires were sent with a response rate of 51%. Of respondents 14% were glaucoma subspecialists. In 69%, the first-line drug-class of choice was a prostaglandin analogue. New Zealand ophthalmologists favoured beta-blockers as their first-line agent because of cost, government restrictions and familiarity. Most respondents stated "hypotensive efficacy" as the most important factor in class choice. Alpha-2-agonists, carbonic anhydrase inhibitors and miotics were considered second-line agents, because of side-effects and lack of hypotensive potency. CONCLUSIONS: The choice of first-line agent for the treatment of glaucoma differed between Australian and New Zealand ophthalmologists, in part as the result of government restriction of prostaglandin-class drugs. Practice patterns seen in Australasia parallel the current evidence base reported in peer-reviewed literature.

Comparison of clinical optic disc assessment with tests of early visual field loss.

PURPOSE: Clinical optic disc assessment may identify glaucomatous optic neuropathy prior to a patient developing visual field abnormalities on achromatic automated peri-metry (AAP). Tests targeting axons that are selectively damaged or whose redundancy is low, such as short wavelength automated perimetry (SWAP) and frequency doubling perimetry (FDP), may detect visual field loss before it is seen on AAP. This study investigated whether patients in whom characteristic glaucomatous optic disc damage was present without AAP abnormalities had visual field abnormalities with SWAP and FDP. METHODS: A sample of patients (n = 50) with ocular hypertension (normal AAP) were selected, who had SWAP, FDP and stereofundus photography performed. The photographs were then analysed by two glaucoma subspecialists who were masked to the assessments of the other and to the patients' SWAP and FDP results. A categorization of the optic discs was made as either normal or abnormal and this was compared with their SWAP and FDP findings. RESULTS: On comparing SWAP and FDP with clinical optic disc assessment as the 'gold standard', the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 33%, 92%, 57% and 81%, respectively, for SWAP and 25%, 89%, 49% and 79%, respectively, for FDP. CONCLUSION: In glaucoma suspects, the study suggests that SWAP and FDP identify subjects with early glaucomatous optic neuropathy missed by AAP.