Patient-reported outcomes (PRO's) in glaucoma: a systematic review

Quality of life in patients with progressive keratoconus treated with corneal collagen crosslinking

PURPOSE

This study aims to analyze the vision-related quality of life (vr-QoL) in keratoconus (KC) patients after corneal crosslinking (CXL).

METHODS

A prospective clinical study was conducted, wherein 41 patients underwent assessment using the "National Eye Institute Visual Functioning Questionnaire" (NEI-25) and the "Keratoconus Outcomes Research Questionnaire" (KORQ) to evaluate vr-QoL, along with the examination of morphology and functional parameters before CXL, and at three and six months post-treatment. Rasch analyses were used to verify the measurement precision of the KORQ with our study population.

RESULTS

There were no statistically significant changes observed in corneal morphology and best corrected visual acuity after CXL. Analysis of the NEI-25 questionnaires and KORQ demonstrated no statistically significant changes throughout the follow-up period. Rasch analyses revealed a high measurement precision of the KORQ within our population.

CONCLUSION

The study indicates that patients with progressive KC maintain stable vr-QoL after undergoing CXL. Based on our findings, we suggest considering very early CXL treatment for KC patients that are at high risk of progression.

Assessment of patient-reported outcomes in vitreomacular interface disorders: A systematic literature review

Patient-reported outcome measures (PROMs) assess the impact of disease on quality of life from the patient's perspective. Our purpose was to provide an overview of current PROMs used for vitreomacular interface disorders: macular hole, epiretinal membrane, and vitreomacular traction. We review the content coverage of all identified PROMs, assess them against quality-of-life issues as identified from earlier qualitative studies, and assess their psychometric quality (measurement properties). We identified 86 studies that used a PROM and 2 qualitative studies on quality of life of patients with a vitreomacular interface disorder. Current PROMs used in vitreomacular interface disorders have a limited content coverage and unknown psychometric quality. The National Eye Institute Visual Functioning Questionnaire was used most. None of the condition-specific PROMs used patient consultation during content development, and there is only a small overlap between the content of PROMs and quality-of-life issues in qualitative studies. Reporting of psychometric quality was sparse and mostly limited to concurrent validity and responsiveness. There is a need for properly developed and validated PROMs in vitreomacular interface disorders.

Peripheral Vision in Patients Following Intraocular Lens Implantation: A Systematic Review and Meta-Analysis

PURPOSE

To update the literature on peripheral optics and vision following intraocular lens (IOLs) implantation.

METHODS

We investigated how current IOLs influence peripheral visual function, peripheral optical quality, and visual perception and performance, in patients following cataract surgery. Peripheral vision is described as vision outside the central foveal region of the eye (beyond 4-5° of eccentricity). We systematically searched PubMed, Cochrane Central Register of Controlled Trials, Embase, and gray literature for relevant references. Randomized controlled trials and observational studies were eligible for inclusion. Finally, 47 studies with a total of 5963 participants were eligible for this review, of which 15 were included in the meta-analysis.

RESULTS

Regarding visual fields, the meta-analysis showed that the pooled estimate of mean deviation (MD) measured with perimetry tests (standard automated perimetry [SAP], short-wavelength automated perimetry [SWAP], and frequency doubling technology [FDT]) appears to be lower than the mean of healthy age-matched controls, regardless of IOL design. Results for pooled estimate show that localized defects (pattern standard deviation [PSD]) were higher than those in the healthy age-matched controls for FDT. We also collected evidence demonstrating that pseudophakia increases peripheral astigmatism and a myopic shift from 20° onward, leading to decreased peripheral image quality compared with that in phakic eyes. Patient-reported outcomes on peripheral vision showed a pooled score estimate of 95.19, indicating high satisfaction, and for the Steps & Stairs questions, a pooled score estimate at 0.23, indicating no to little difficulty seeing steps and stairs.

CONCLUSIONS

Peripheral image quality is degraded in eyes after cataract surgery. Nevertheless, whether this degradation leads to impaired visual function in the periphery requires further investigation.

Efficiency, Precision, Validity, and Reliability of GlauCAT-Asian Computerized Adaptive Tests in Measuring Glaucoma-Related Quality of Life

Purpose

To determine the efficiency, precision, and agreement of GlauCAT-Asian and its corresponding validity and reliability.

Methods

In this cross-sectional study, 219 participants (mean ± standard deviation age, 66.59 ± 8.61 years; 34% female) across the spectrum of glaucoma severity and 50 glaucoma suspects were recruited from glaucoma clinics in Singapore. Participants answered seven computerized adaptive testing (CAT) evaluations (Ocular Comfort, Activity Limitation, Lighting, Mobility, Concerns, Psychosocial, Glaucoma Management) and underwent eye examinations. Efficiency (mean number of items required for each CAT and time taken for CAT versus full item banks [IBs]), agreement (concordance between CATs and full IB person measures, henceforth referred to as scores), and precision (standard error of measurement [SE]) were evaluated. Other validity and reliability metrics were also assessed.

Results

The mean number of items administered ranged from 9 (Mobility/Glaucoma Management) to 12 (Ocular Comfort). Compared to answering the full IBs, CATs provided an average time saving of 38.3% (range, 10% to 70.6% for Lighting and Activity Limitation, respectively). Agreement between scores obtained by CAT versus full IB was high (intracorrelation coefficient ≥0.75), as was precision of score estimates (mean SE range: 0.35 for Psychosocial to 0.29 for Mobility). Scores from Activity Limitation, Mobility, Lighting, and Concerns decreased significantly as glaucoma severity increased (criterion validity; P-trend <0.05). All tests displayed good convergent/divergent validity and test-retest reliability.

Conclusions

GlauCAT-Asian provides efficient, precise, accurate, valid, and reliable measurement of the patient-centered impact of glaucoma.

Translational Relevance

GlauCAT-Asian may provide a valuable clinical tool for ophthalmologists to monitor impact of disease progression and the effectiveness of therapies.

Challenging the "Topical Medications-First" Approach to Glaucoma: A Treatment Paradigm in Evolution

Topical glaucoma medications are effective and safe, but they have numerous well-documented limitations that diminish their long-term utility and sustainability. These limitations can include high rates of nonadherence (with associated glaucoma progression), concerning side effects, inconsistent circadian intraocular pressure (IOP) control, complex dosing regimens, difficulty with self-administration, costs, and decreased quality of life. Despite these limitations, topical medications traditionally have been first-line in the glaucoma treatment algorithm, as no other minimally invasive treatment alternatives existed. In recent years, however, novel interventional therapies-including sustained-release drug-delivery platforms, selective laser trabeculoplasty, and micro-invasive glaucoma surgery procedures-have made it possible to intervene earlier without relying on topical medications. As a result, the topical medication-first treatment approach is being reevaluated in an overall shift toward earlier more proactive interventions.

Evaluating Measurement Properties of Patient-Reported Outcome Measures in Glaucoma: A Systematic Review

TOPIC

The purpose of the current study was to systematically identify and evaluate existing patient-reported outcome measures (PROMs) for clinical glaucoma practice.

CLINICAL RELEVANCE

Understanding and incorporating patient preferences into decision-making is now recognized as critical for optimal resource allocation, especially in technologically advancing areas, such as minimally invasive surgeries. Patient-reported outcome measures are instruments designed to evaluate the health outcomes that are most important to patients. Despite their recognized importance, especially in the era of patient-centered care, their routine use in clinical settings remains low.

METHODS

A systematic literature search was conducted in 6 databases (EMBASE, MEDLINE, PsycINFO, Scopus, BIOSIS, and Web of Science) from the date of inception. Studies were included in the qualitative review if they reported measurement properties of PROMs in adult patients with glaucoma. COnsensus-based Standards for the selection of health Measurement INstruments guidelines were used to assess the included PROMs. The study protocol is registered with PROSPERO (registration number: CRD42020176064).

RESULTS

The literature search yielded 2661 records. After deduplication, 1259 studies entered level 1 screening, and based on title and abstract review, 164 records proceeded to full-text screening. In 48 included studies, 70 instrument reports discuss 43 distinct instruments in 3 major categories: glaucoma-specific, vision-specific, and general health-related quality of life. Most used measures were glaucoma-specific (Glaucoma Quality of Life [GQL] and Glaucoma Symptom Scale [GSS]) and vision-specific (National Eye Institute Visual Function Questionnaire [NEI VFQ-25]). All 3 have sufficient validity (especially construct), with GQL and GSS having sufficient internal consistency, cross-cultural validity, and reliability, with reports suggesting high methodological quality.

CONCLUSION

The GQL, GSS, and NEI VFQ-25 are the 3 most used questionnaires in a research setting, having considerable validation in a patient population with glaucoma. Limited reports on interpretability, responsiveness, and feasibility in all 43 identified instruments make identifying a single optimal questionnaire for clinical use challenging and highlight the need for further studies.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Patient-reported outcomes in patients with vitreous floaters: A systematic literature review

Seeking treatment for bothersome vitreous floaters is patient driven. To measure the impact of floaters and treatment on an individual's quality of life, patient-reported outcome measurements (PROMs) are essential. We review all studies using a PROM for patients with floaters. We evaluated content coverage against quality-of-life domains previously identified in other ophthalmic disorders, and against a qualitative study investigating quality-of-life issues in patients with floaters. We assessed measurement properties of PROMs using an extensive range of psychometric quality criteria. We identified 59 studies using 28 different PROMs. Many PROMs were not specifically developed for patients with floaters. Floater-specific PROMs were mostly based on content validation from an ophthalmologist or researcher perspective; two included a patient perspective. Using the outcomes of the qualitative study, we found that the floater-specific PROMs were narrow in their content coverage, with most items relating to visual symptoms and activity limitations. Testing the psychometric quality of PROMs was rare, and when employed mostly limited to responsiveness and known group validity. The remarkable high number of floater-specific PROMs reveals a need for such measurements in ophthalmology. Unfortunately, reporting on psychometric quality is limited, and content development is most often done without patient involvement.

Distinguishing Glaucoma, Cataract, and Glaucoma Suspect Based on Visual Symptoms

PRCIS

Cataract, glaucoma, and glaucoma suspect patients report differing visual symptoms. Asking patients about their visual symptoms may provide useful diagnostic information and inform decision-making in patients with comorbid conditions.

PURPOSE

To compare visual symptoms in glaucoma, glaucoma suspect (controls), and cataract patients.

METHODS

Glaucoma, cataract, and glaucoma suspect patients at Wilmer Eye Institute responded to a questionnaire rating the frequency and severity of 28 symptoms. Univariate and multivariable logistic regression determined the symptoms that best differentiate each disease pair.

RESULTS

In all, 257 patients (mean age: 67.4 ± 13.4 y; 57.2% female; 41.2% employed), including 79 glaucoma, 84 cataract, and 94 glaucoma suspect patients, participated. Compared with glaucoma suspects, glaucoma patients were more likely to report poor peripheral vision (OR 11.29, 95% CI: 3.73-34.16), better vision in 1 eye (OR 5.48, 95% CI: 1.33-22.64), and light sensitivity (OR 4.85, 95% CI: 1.78-13.24), explaining 40% of the variance in diagnosis (ie, glaucoma vs. glaucoma suspect). Compared with controls, cataract patients were more likely to report light sensitivity (OR 3.33, 95% CI: 1.56-7.10) and worsening vision (OR 12.20, 95% CI: 5.33-27.89), explaining 26% of the variance in diagnosis (ie, cataract vs. glaucoma suspect). Compared with cataract patients, glaucoma patients were more likely to report poor peripheral vision (OR 7.24, 95% CI: 2.53-20.72) and missing patches (OR 4.91, 95% CI: 1.52-15.84), but less likely to report worsening vision (OR 0.08, 95% CI 0.03-0.22), explaining 33% of the variance in diagnosis (ie, glaucoma vs. cataract).

CONCLUSIONS

Visual symptoms distinguish disease state to a moderate degree in glaucoma, cataract, and glaucoma suspect patients. Asking about visual symptoms may serve as a useful diagnostic adjunct and inform decision-making, for example, in glaucoma patients considering cataract surgery.

The development of a glaucoma-specific health-related quality of life item bank supporting a novel computerized adaptive testing system in Asia

Background

A glaucoma-specific health-related quality of life (HRQoL) item bank (IB) and computerized adaptive testing (CAT) system relevant to Asian populations is not currently available. We aimed to develop content for an IB focusing on HRQoL domains important to Asian people with glaucoma; and to compare the content coverage of our new instrument with established glaucoma-specific instruments.

Methods

In this qualitative study of glaucoma patients recruited from the Singapore National Eye Centre (November 2018-November 2019), items/domains were generated from: (1) glaucoma-specific questionnaires; (2) published articles; (3) focus groups/semi-structured interviews with glaucoma patients (n = 27); and (4) feedback from glaucoma experts. Data were analyzed using the constant comparative method. Items were systematically refined to a concise set, and pre-tested using cognitive interviews with 27 additional glaucoma patients.

Results

Of the 54 patients (mean ± standard deviation [SD] age 66.9 ± 9.8; 53.7% male), 67 (62.0%), 30 (27.8%), and 11 (10.2%) eyes had primary open angle glaucoma, angle closure glaucoma, and no glaucoma respectively. Eighteen (33.3%), 11 (20.4%), 8 (14.8%), 12 (22.2%), and 5 (9.3%) patients had no, mild, moderate, severe, or advanced/end-stage glaucoma (better eye), respectively. Initially, 311 items within nine HRQoL domains were identified: Visual Symptoms, Ocular Comfort Symptoms, Activity Limitation, Driving, Lighting, Mobility, Psychosocial, Glaucoma management, and Work; however, Driving and Visual Symptoms were subsequently removed during the refinement process. During cognitive interviews, 12, 23 and 10 items were added, dropped and modified, respectively.

Conclusion

Following a rigorous process, we developed a 221-item, 7-domain Asian glaucoma-specific IB. Once operationalised using CAT, this new instrument will enable precise, rapid, and comprehensive assessment of the HRQoL impact of glaucoma and associated treatment efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41687-022-00513-3.

Integrating Spinal Cord Injury - Quality of Life instruments into rehabilitation: Implementation science to guide adoption of patient-reported outcome measures

Context/objective: This study describes a development strategy for integrating the Spinal Cord Injury - Quality of Life (SCI-QOL) item banks into inpatient spinal cord injury (SCI) rehabilitation and recommendations for protocol implementation.Design: We adopted an implementation science approach to develop a strategy for adapting and contextualizing SCI-QOL use during SCI rehabilitation. We conducted focus groups and stakeholder meetings with clinical assessment champions to (1) identify barriers and supports to SCI-QOL adoption; (2) reduce barriers and emphasize supports; (3) evaluate and select relevant SCI-QOL domains and item banks; (4) develop administration and reporting guidelines; and (5) identify hospital roles to alert with SCI-QOL results.Setting: A regional inpatient rehabilitation hospital. This study focuses on clinicians providing inpatient rehabilitation to patients with SCI.Participants: Fifty-nine clinicians, including physicians, speech language pathologists, occupational and physical therapists, nurses, and social workers providing care to SCI inpatients.Interventions: N/A.Outcome measures: N/A.Results: Clinicians identified the SCI-QOL domains that were most relevant to inpatient care; when SCI-QOL should be administered; what hospital roles were best suited for administering SCI-QOL; how results should be displayed in the electronic medical record; and which clinical roles needed notification of SCI-QOL results.Conclusions: Clinicians acknowledge the value of patient-reported outcome measures in inpatient SCI rehabilitation, but noted barriers to adoption. Engaging clinicians in the decision-making process for developing an implementation and administration protocol can inform strategies to overcome barriers and emphasize supports.

A Scoping Review of Quality of Life Questionnaires in Glaucoma Patients

PRECIS

Multiple questionnaires exist to measure glaucoma's impact on quality of life (QoL). Selecting the right questionnaire for the research question is essential, as is patients' acceptability of the questionnaire to enable collection of relevant patient-reported outcomes.

PURPOSE

QoL relating to a disease and its treatment is an important dimension to capture. This scoping review sought to identify the questionnaires most appropriate for capturing the impact of glaucoma on QoL.

METHODS

A literature search of QoL questionnaires used in glaucoma, including patient-reported outcomes measures, was conducted and the identified questionnaires were analyzed using a developed quality criteria assessment.

RESULTS

Forty-one QoL questionnaires were found which were analyzed with the detailed quality criteria assessment leading to a summary score. This identified the top 10 scoring QoL questionnaires rated by a synthesis of the quality criteria grid, considering aspects such as reliability and reproducibility, and the authors' expert clinical opinion. The results were ratified in consultation with an international panel of ophthalmologists (N=49) from the Educational Club of Ocular Surface and Glaucoma representing 23 countries.

CONCLUSIONS

Wide variability among questionnaires used to determine vision related QoL in glaucoma and in the responses elicited was identified. In conclusion, no single existing QoL questionnaire design is suitable for all purposes in glaucoma research, rather we have identified the top 10 from which the questionnaire most appropriate to the study objective may be selected. Development of a new questionnaire that could better distinguish between treatments in terms of vision and treatment-related QoL would be useful that includes the patient perspective of treatment effects as well as meeting requirements of regulatory and health authorities. Future work could involve development of a formal weighting system with which to comprehensively assess the quality of QoL questionnaires used in glaucoma.

A Review of Studies of the Association of Vision-Related Quality of Life with Measures of Visual Function and Structure in Patients with Glaucoma in the United States

Purpose: To investigate the association of quality of life (QoL) with ocular structure and function in glaucoma patients, and to identify which aspects of QoL are most closely tied to Visual Field (VF) and Visual Acuity (VA).Methods: We conducted a comprehensive review of studies on QoL in glaucoma patients using PubMed, Web of Science, and Google Scholar (from 1 January 1997 to 7 December 2019). A total of 21 studies in the United States that used the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ) or 51-item NEI VFQ were included. A descriptive analysis of data from the selected studies was conducted. The association between QoL scores and visual function and structure was investigated by ranking the strength of association on a scale from 1 (weakest) to 12 (strongest).Results: Studies reported correlations between QoL scores and Visual Structure. Associations were also reported between QoL and Visual Function both cross-sectionally and longitudinally, with a stronger association of VF and VA with distance activities (average ranking 9.1 and 9.6), vision-specific dependency (8.7 and 8.9), and driving (8.6 and 9.7). Vision-specific mental health (6.5 and 4.9), vision-specific social functioning (8.4 and 6.2), and vision-specific role difficulties (7.1 and 6.6) domains were more associated with VF than with VA.Conclusion: Our study was the first to quantify and rank the strength of association between visual function and QoL domains. Driving and psycho-social QoL domains tended to be most affected by glaucoma-related deterioration of visual function. QoL scores could be used for more patient-centered disease management.

The Computerized Glaucoma Visual Function Test: A Pilot Study Evaluating Computer-Screen Based Tests of Visual Function in Glaucoma

Purpose

We aimed to develop and evaluate the Computerized Glaucoma Visual Function Test (CoGVFT), among a cohort of glaucoma patients, and identify potential new items to optimize the test.

Method

A cross-sectional study involving 84 patients with open-angle glaucoma of varying severity and 18 controls without glaucoma were recruited. Better and worse eye visual field parameters, visual acuity, contrast sensitivity, 6-Part Cognitive Impairment Test (6CIT) and Glaucoma Activity Limitation-9 (GAL-9) questionnaire responses were recorded. The CoGVFT was administered to all participants. Rasch analysis was used to assess the psychometric properties of the CoGVFT, which was then evaluated with criterion, convergent, and divergent validity tests. Regression modeling determined factors predictive of CoGVFT performance.

Results

The 38-item CoGVFT demonstrated convergent validity with statistically significant differences in glaucoma severity groups (P < 0.001, analysis of variance). The correlation coefficient for CoGVFT person measures (logits) with GAL-9 person measures (logits) and better eye (BE) mean deviation was 0.528 (P < 0.001) and 0.762 (P < 0.001), respectively, demonstrating convergent validity. Divergent validity was suboptimal as the 6CIT score demonstrated moderate correlation (r = 0.463, P < 0.001) with CoGVFT person measures (logits). Multivariable analysis revealed that better BE contrast sensitivity, lower age, and better BE visual acuity were associated with better CoGVFT performance (P < 0.001).

Conclusions

The CoGVFT retains most of the features of its predecessor to estimate vision-based activity limitation related to glaucoma.

Translational Relevance

The CoGVFT is an easily accessible tool that can potentially be used in the community to help detect undiagnosed glaucoma in the population.

Practical Barriers to Medication Adherence: What Do Current Self- or Observer-Reported Instruments Assess?

Introduction

Practical adherence barriers (e.g., medication frequency) are generally more amenable to intervention than perceptual barriers (e.g., beliefs). Measures which assess adherence barriers exist, however these tend to measure a mix of factors. There is a need to identify what practical barriers are captured by current measures.

Aim

To identify and synthesise the practical adherence barriers which are assessed by currently available self- or observer-report adherence measures.

Methods

A search for systematic reviews of self- or observer-report report adherence measures was conducted. Three electronic databases (Embase, Ovid Medline, and PsycInfo) were searched using terms based on adherence, adherence barriers and measures. Systematic reviews reporting on adherence measures which included at least one self- or observer-report questionnaire or scale were included. Adherence measures were extracted and coded on whether they addressed perceptual or practical barriers, or both. Practical items were then analysed thematically.

Results

Following screening of 272 initial abstracts, 20 full-text papers were reviewed. Four were excluded after full-text review, leaving 16 systematic reviews for data extraction. From these, 187 different adherence measures were extracted and coded, and 23 unique measures were identified as assessing practical barriers and included in the final analysis. Seven key themes were identified: formulation; instructions for use; issues with remembering; capability—knowledge and skills; financial; medication supply and social environment.

Conclusion

Existing adherence measures capture a variety of practical barriers which can be grouped into seven categories. These findings may be used to inform the development of a measure of practical adherence barriers.

Advanced glaucoma at diagnosis: current perspectives

Presentation with advanced glaucoma is a significant risk factor for lifetime blindness. The asymptomatic nature of glaucoma, particularly in early disease, means that substantial vision loss in one eye does not always translate into a perceptible loss of visual function. This, along with the lack of an effective screening strategy, contributes to late presentation. Those most at risk of presenting with advanced glaucoma have asymptomatic high intraocular pressure (IOP), no family history of glaucoma, are socially disadvantaged, and do not attend sight testing. Patients with glaucoma may have impaired functionality for daily activities, such as reading, walking and driving. Quality of life measures have shown this to be significantly worse in patients with more severe visual field loss, particularly if bilateral. In addition, quality of life decreases faster with further bilateral visual field loss when advanced visual field damage is present. Management of these patients requires disproportionally more resources than those with earlier disease. Both medical and surgical options are used as the initial approach to treat patients presenting with advanced glaucoma. The most recently published National Institute for Health and Care Excellence (NICE) guidelines suggest that patients presenting with advanced disease should be offered trabeculectomy as a primary intervention. However, more evidence is required to determine the best initial management. The Treatment of Advanced Glaucoma Study (TAGS) is being conducted, comparing primary medical management with primary mitomycin C-augmented trabeculectomy for people presenting with advanced open-angle glaucoma. The results of TAGS will provide robust evidence for the most appropriate initial intervention.

How do different lighting conditions affect the vision and quality of life of people with glaucoma? A systematic review

This article is a systematic review of evidence regarding the impact of different lighting conditions on the vision and quality of life (QoL) of people with primary open-angle glaucoma (POAG). A systematic literature search was carried out using CINAHL, MEDLINE, PsycARTICLES, PsycINFO, Embase, and Ovid Nursing Database for studies: published up to April 2019; including people diagnosed with POAG; and assessing visual function or QoL in response to changing lighting/luminance levels or glare. Two researchers independently screened studies for eligibility. Data were extracted from eligible studies regarding study design, participant characteristics, outcomes, and results. Quality of included studies was critically appraised. Of 8437 studies, 56 eligible studies were included. Studies investigated the effects of lighting on the following domains among people with POAG: QoL (18/56), psychophysical measures (16/56), functional vision (10/56), activities of daily living (10/56), and qualitative findings (2/56). POAG negatively affects low-luminance contrast sensitivity, glare symptoms, and dark adaptation time and extent. In vision-related QoL questionnaires, people with POAG report problems with lighting, glare, and dark adaptation more frequently than any other domain. These problems worsen with progressing visual field loss. Early-stage POAG patients experience significantly more difficulties in low-luminance or changing lighting conditions than age-matched controls (AMCs), challenging perceptions of early-stage POAG as asymptomatic. However, performance-based studies seldom show significant differences between POAG participants and AMCs on tasks simulating daily activities under non-optimal lighting conditions. Further research with larger samples is required to optimise ambient and task-oriented lighting that can support patients' adaptation to POAG.

Beyond intraocular pressure: Optimizing patient-reported outcomes in glaucoma

Glaucoma, an irreversible blinding condition affecting 3-4% adults aged above 40 years worldwide, is set to increase with a rapidly aging global population. Raised intraocular pressure (IOP) is a major risk factor for glaucoma where the treatment paradigm is focused on managing IOP using medications, laser, or surgery regimens. However, notwithstanding IOP and other clinical parameters, patient-reported outcomes, including daily functioning, emotional well-being, symptoms, mobility, and social life, remain the foremost concerns for people being treated for glaucoma. These outcomes are measured using objective patient-centered outcome measures (PCOMs) and subjective patient-reported outcome measures (PROMs). Studies using PCOMs have shown that people with glaucoma have several mobility, navigational and coordination challenges; reading and face recognition deficits; and are slower in adapting to multiple real-world situations when compared to healthy controls. Similarly, studies have consistently demonstrated, using PROMs, that glaucoma substantially and negatively impacts on peoples' self-reported visual functioning, mobility, independence, emotional well-being, self-image, and confidence in healthcare, compared to healthy individuals, particularly in those with late-stage disease undergoing a heavy treatment regimen. The patient-centred effectiveness of current glaucoma treatment paradigms is equivocal due to a lack of well-designed randomized controlled trials; short post-treatment follow-up periods; an inappropriate selection or availability of PROMs; and/or an insensitivity of currently available PROMs to monitor changes especially in patients with newly diagnosed early-stage glaucoma. We provide a comprehensive, albeit non-systematic, critique of the psychometric properties, limitations, and recent advances of currently available glaucoma-specific PCOMs and PROMs. Finally, we propose that item banking and computerized adaptive testing methods can address the multiple limitations of paper-pencil PROMs; customize their administration; and have the potential to improve healthcare outcomes for people with glaucoma.

Ocular surface response and subjective symptoms associated to lens care solutions in Palestine

PURPOSE

To compare the biocompatibility and subjective symptoms of four multipurpose solutions marketed in Palestine with hydrogel contact lenses.

METHODS

50 habitual soft contact lens wearers were recruited in this interventional crossover study. Subjects were asked to attend the optometry clinic five times. A new pair of hydrogel lenses (Bioxifilcon-B) were fitted each time. This pair was soaked randomly overnight in one of the following four-multipurpose solutions (NEOPLUS®, AvizorUnicaSensitive®, ReNuMultiPlus® and COMPLETERevitaLens®) which contain different disinfecting agents (PHMB, Phx, PAPB, and PQ-1+Alexidine, respectively), or non-preserved saline. At each visit, corneal staining, ocular redness and subjective symptoms were assessed.

RESULTS

The percentage of corneal staining increased significantly (P≤0.050) after soaking the lenses with PHMB (86%), PAPB (64%) and Phx (32%) based-solutions. However, a non-significant increase was noticed after the use of PQ-1+Alexidine based solution (30%, P=0.083). Ocular redness evaluation showed a significant increase (P≤0.050) in limbal hyperemia after the use of all solutions, while bulbar redness was significantly increased after the use of biguanide-based solutions (P≤0.050). The subjective assessment analysis showed a non-significant change in comfort, dryness, photophobia and scratchiness (P≥0.050) at 2-h intervention using all solutions, except for the PHMB based solution which showed a significant change in subjective symptoms (P≤0.050).

CONCLUSION

The combination of Bioxifilcon-B hydrogel contact lenses and solution containing PHMB, PAPB and Phx-disinfectants induced a significant increase in corneal staining after 2h of CL-wear with a higher severity when the PHMB-based solution was used, while the PQ-1+Alexidine-based solution did not. Only the PHMB-based solution triggered a significant change in subjective symptoms which might which suggests that it might be related to the severity of staining rather than the induction of staining.

Glaucoma-Associated Visual Task Performance and Vision-Related Quality of Life in South India

OBJECTIVE/PURPOSE

Performance-based measures may provide an objective assessment of how glaucoma affects daily functioning. We sought to validate a clinically-applicable performance-based measure of visual ability for patients with glaucoma in south India and to describe its relationship to clinical and patient-reported outcomes.

DESIGN

Cross-sectional validation study.

SUBJECTS/PARTICIPANTS/CONTROLS

145 participants with glaucoma were recruited at Aravind Eye Hospital.

METHODS/INTERVENTION/TESTING

We modified the compressed assessment of activities related to vision (CAARV), a performance-based measure validated in the U.S., to be culturally relevant in south India. Participants underwent a series of tests, including the Indian CAARV (I-CAARV), Indian Visual Functioning Questionnaire (IND-VFQ), Spaeth/Richman Contrast Sensitivity (SPARCS) test, standard automated perimetry, and visual acuity (VA). Factor analysis and Rasch modeling were used to validate the I-CAARV. Correlations between the I-CAARV and other outcomes were evaluated.

MAIN OUTCOME MEASURE

Psychometric properties of the I-CAARV for individuals with glaucoma in south India.

RESULTS

The study included 142 participants (51.7% female, mean age 56.4 years). Average presenting visual acuity and visual field mean deviation (MD) in the better-seeing eye were 0.26 logMAR and -6.57 dB, respectively. The four tasks of the I-CAARV were found to measure a single underlying construct. Rasch analysis of the I-CAARV revealed that the outcome measure had moderate reliability, good construct and content validity, and fair measurement precision. Tasks were well-targeted to the study sample. Rasch-calibrated scores on the I-CAARV were significantly correlated with Rasch-calibrated IND-VFQ scores (r=-0.54) and with visual field MD, presenting VA, best-corrected VA, and SPARCS contrast sensitivity in both the better-seeing eye (r=0.60, -0.51, -0.53, 0.76, respectively) and worse-seeing eye (r=0.48, -0.61, -0.46, 0.69, respectively).

CONCLUSIONS

The I-CAARV is a valid performance-based measure of vision-dependent functioning in glaucoma in south India. This study also found that I-CAARV task performance was strongly correlated with contrast sensitivity and suggests that performance-based and patient-reported outcomes are related but distinct measures of the impact of glaucoma on functioning and vision-related quality of life. Future studies are needed to determine the sensitivity of the I-CAARV to detect changes due to disease progression that are relevant to functioning and vision-related quality of life.

The impact of primary open-angle glaucoma: Comparison of vision-specific (National Eye Institute Visual Function Questionnaire-25) and disease-specific (Glaucoma Quality of Life-15 and Viswanathan 10) patient-reported outcome (PRO) instruments

Purpose:

To compare a general vision-specific patient-reported outcomes (PRO) instrument, National Eye Institute Visual Function Questionnaire-25 (NEIVFQ-25) with two disease-specific PRO instruments, Glaucoma Quality of Life-15 (GQL-15), and Viswanathan 10 in patients with varying severity of primary open angle glaucoma (POAG).

Methods:

This hospital-based, prospective study enrolled 140 glaucoma patients. The patients were classified into mild, moderate, and severe glaucoma based on visual field defects. All these patients were administered the three PRO instruments and the results were statistically analyzed.

Results:

All the three instruments showed high internal consistency (Cronbach's alpha for GQL-15, NEIVFQ-25, and Viswanathan 10 were 0.918, 0.937, and 0.929, respectively) There was a statistically significant difference between patients with mild, moderate, and severe POAG with all instruments (P ≤ 0.001). The instruments correlated well across several parameters especially the peripheral vision and glare/dark adaptation. The disease-specific scales however are simpler and faster to administer.

Conclusion:

All three instruments were reliable in assessment of mild, moderate, and severe glaucoma. They correlated strongly with each other in most of the related subscales, domains, and questions. NEIVFQ-25 additionally gave information regarding the general, psychological, and social effects of the disease.

The use of patient-reported outcome research in modern ophthalmology: impact on clinical trials and routine clinical practice

This review article considers the rising demand for patient-reported outcome measures (PROMs) in modern ophthalmic research and clinical practice. We review what PROMs are, how they are developed and chosen for use, and how their quality can be critically appraised. We outline the progress made to develop PROMs in each clinical subspecialty. We highlight recent examples of the use of PROMs as secondary outcome measures in randomized controlled clinical trials and consider the impact they have had. With increasing interest in using PROMs as primary outcome measures, particularly where interventions have been found to be of equivalent efficacy by traditional outcome metrics, we highlight the importance of instrument precision in permitting smaller sample sizes to be recruited. Our review finds that while there has been considerable progress in PROM development, particularly in cataract, glaucoma, medical retina, and low vision, there is a paucity of useful tools for less common ophthalmic conditions. Development and validation of item banks, administered using computer adaptive testing, has been proposed as a solution to overcome many of the traditional limitations of PROMs, but further work will be needed to examine their acceptability to patients, clinicians, and investigators.

Usage of glaucoma-specific patient-reported outcome measures (PROMs) in the Singapore context: a qualitative scoping exercise

Background

Despite the increasing emphasis on the role of glaucoma-specific patient-reported outcome measures (PROMs) as relevant outcome measures for the impact of glaucoma and its intervention on patients' daily lives, the feasibility of implementing PROMs in the routine clinical setting in Singapore remains undefined. We aim to evaluate the comprehensibility, acceptability, and relevance of four glaucoma-specific PROMs at healthcare professionals' and patients' level in a Singapore context.

Methods

Sixteen ophthalmic healthcare professionals and 24 glaucoma patients, with average age 60 years (SD = 15), were invited from a tertiary hospital in Singapore. Semi-structured interviews were conducted to explore participants’ perceptions on the content and administration of four glaucoma-specific PROMs - the Glaucoma Quality of Life-15, Glaucoma Symptom Identifier, Independent Mobility Questionnaire and Treatment Satisfaction Survey of Intra-ocular Pressure. Semi-structured interviews were hand transcribed, and analysed thematically. Each participant filled out a feasibility survey at the end of interview.

Results

79% of glaucoma patients and 94% of glaucoma healthcare professionals felt selected PROMs relevant to patients. 63% of glaucoma patients and 50% of healthcare professionals felt that selected PROMs were sufficiently comprehensive for clinical use. 46% of glaucoma patients and 56% of healthcare professionals felt selected PROMs were user-friendly.

Conclusions

Using PROMs in the Singapore clinical setting receives promising support from both healthcare professionals and patients. The identified potential barriers tailored to Singapore clinical setting will help successful implementation of PROMs into routine clinical care.

Patient-reported Outcomes for Assessment of Quality of Life in Refractive Error: A Systematic Review

SIGNIFICANCE

This review has identified the best existing patient-reported outcome (PRO) instruments in refractive error. The article highlights the limitations of the existing instruments and discusses the way forward.

PURPOSE

A systematic review was conducted to identify the types of PROs used in refractive error, to determine the quality of the existing PRO instruments in terms of their psychometric properties, and to determine the limitations in the content of the existing PRO instruments.

METHODS

Articles describing a PRO instrument measuring 1 or more domains of quality of life in people with refractive error were identified by electronic searches on the MEDLINE, PubMed, Scopus, Web of Science, and Cochrane databases. The information on content development, psychometric properties, validity, reliability, and responsiveness of those PRO instruments was extracted from the selected articles. The analysis was done based on a comprehensive set of assessment criteria.

RESULTS

One hundred forty-eight articles describing 47 PRO instruments in refractive error were included in the review. Most of the articles (99 [66.9%]) used refractive error-specific PRO instruments. The PRO instruments comprised 19 refractive, 12 vision but nonrefractive, and 16 generic PRO instruments. Only 17 PRO instruments were validated in refractive error populations; six of them were developed using Rasch analysis. None of the PRO instruments has items across all domains of quality of life. The Quality of Life Impact of Refractive Correction, the Quality of Vision, and the Contact Lens Impact on Quality of Life have comparatively better quality with some limitations, compared with the other PRO instruments.

CONCLUSIONS

This review describes the PRO instruments and informs the choice of an appropriate measure in refractive error. We identified need of a comprehensive and scientifically robust refractive error-specific PRO instrument. Item banking and computer-adaptive testing system can be the way to provide such an instrument.

The ELPAT living organ donor Psychosocial Assessment Tool (EPAT): from 'what' to 'how' of psychosocial screening - a pilot study

Thorough psychosocial screening of donor candidates is required in order to minimize potential negative consequences and to strive for optimal safety within living donation programmes. We aimed to develop an evidence-based tool to standardize the psychosocial screening process. Key concepts of psychosocial screening were used to structure our tool: motivation and decision-making, personal resources, psychopathology, social resources, ethical and legal factors and information and risk processing. We (i) discussed how each item per concept could be measured, (ii) reviewed and rated available validated tools, (iii) where necessary developed new items, (iv) assessed content validity and (v) pilot-tested the new items. The resulting ELPAT living organ donor Psychosocial Assessment Tool (EPAT) consists of a selection of validated questionnaires (28 items in total), a semi-structured interview (43 questions) and a Red Flag Checklist. We outline optimal procedures and conditions for implementing this tool. The EPAT and user manual are available from the authors. Use of this tool will standardize the psychosocial screening procedure ensuring that no psychosocial issues are overlooked and ensure that comparable selection criteria are used and facilitate generation of comparable psychosocial data on living donor candidates.

Association of Glaucoma-Related, Optical Coherence Tomography-Measured Macular Damage With Vision-Related Quality of Life

Importance

Little is known about the association between structural macular damage and self-reported visual function of people with glaucoma.

Objective

To determine the association between vision-related quality of life among patients with primary open-angle glaucoma with structural macular retinal ganglion cell plus inner plexiform layer (RGC+IPL) loss identified by spectral-domain optical coherence tomography (SD-OCT) machine-generated deviation maps and thickness measurements.

Design, Setting, and Participants

This cross-sectional prospective study was conducted from March 1, 2014, to March 30, 2015, at the Department of Ophthalmology at Columbia University Medical Center. The participants were 107 patients who were enrolled in the study and represented the entire range of glaucomatous damage. All 214 eyes of the 107 participants underwent 10-2 visual field tests and SD-OCT scans, and all participants completed the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). They also received ophthalmologic examination, including medical history review, best-corrected visual acuity, slitlamp biomicroscopy, intraocular pressure measurement, gonioscopy, dilated ophthalmoscopy, and standard automated perimetry. Macular RGC+IPL loss was determined by diffuse or focal patterns on SD-OCT-generated deviation maps (probability map that compared patients with aged-matched normative database) and thickness measurements.

Main Outcomes and Measures

Regression analyses to assess the association of NEI VFQ-25 scores (score range: 41.9-99.5; higher scores indicate better functioning) with patterns of RGC+IPL loss and with RGC+IPL thickness measurements.

Results

Of the 107 patients, 48 (45%) were men and the mean (SD) age was 65 (11) years. The self-reported race/ethnicity of participants consisted of 45 (46%) black, 47 (48%) white, and 6 (6%) "other" individuals. In the univariable analyses, patients with diffuse macular RGC+IPL loss had mean composite Rasch-calibrated NEI VFQ-25 scores that were 6.15 points lower than the scores of patients with focal damage (β = -6.15; 95% CI, -11.7 to -0.59; P = .03). The effect remained significant even after controlling for mean RGC+IPL thickness (β = -7.64; 95% CI, -14.2 to -1.03; P = .02).

Conclusions and Relevance

Characteristic patterns of glaucoma-related macular RGC+IPL loss appeared to be more important predictors of vision-related quality of life than thickness measures, with diffuse RGC+IPL loss as an indicator for diminished vision-related quality of life.

Quality of Life in Glaucoma: A Review of the Literature

The ultimate goal of glaucoma management is the preservation of patients’ visual function and quality of life (QoL). The disease itself as well as the medical or surgical treatment can have an enormous impact on a patient’s QoL. Even the mere diagnosis of a chronic, irreversible, potentially blinding disorder can adversely affect the patient’s sense of well-being and QoL by eliciting significant anxiety. Patients with primary open-angle glaucoma rarely present with visual symptoms, at least early in the course of the disease. A better understanding of patient-reported QoL can improve patient–physician interaction and enhance treatment adherence by customizing treatment options based on individual patient profile, thus optimizing long-term prognosis. These aspects are summarized and critically appraised in this article.

Association between progressive retinal nerve fiber layer loss and longitudinal change in quality of life in glaucoma

IMPORTANCE

Evaluation of structural optic nerve damage is a fundamental part of diagnosis and management of glaucoma. However, the relationship between structural measurements and disability associated with the disease is not well characterized. Quantification of this relationship may help validate structural measurements as markers directly relevant to quality of life.

OBJECTIVE

To evaluate the relationship between rates of retinal nerve fiber layer (RNFL) loss and longitudinal changes in quality of life in glaucoma.

DESIGN, SETTING, AND PARTICIPANTS

Observational cohort study including 260 eyes of 130 patients with glaucoma followed up for a mean (SD) of 3.5 (0.7) years. All patients had repeatable visual field defects on standard automated perimetry (SAP) at baseline. The 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was performed annually, and spectral-domain optical coherence tomography and SAP were performed at 6-month intervals. A joint model was used to investigate the association between change in NEI VFQ-25 Rasch-calibrated scores and change in RNFL thickness, adjusting for confounding socioeconomic and clinical variables.

MAIN OUTCOMES AND MEASURES

Association between change in binocular RNFL thickness (RNFL thickness in the better eye at each point) and change in NEI VFQ-25 scores.

RESULTS

Progressive binocular RNFL thickness loss was associated with worsening of NEI VFQ-25 scores over time. In a multivariable model adjusting for baseline disease severity and the rate of change in binocular SAP sensitivity, each 1-μm-per-year loss of RNFL thickness was associated with a decrease of 1.3 units (95% CI, 1.02-1.56) per year in NEI VFQ-25 scores (P < .001). After adjusting for the contribution from SAP, 26% (95% CI, 12%-39%) of the variability of change in NEI VFQ-25 scores was associated uniquely with change in binocular RNFL thickness. The P value remained less than .001 after adjusting for potential confounding factors.

CONCLUSIONS AND RELEVANCE

Progressive binocular RNFL thickness loss was associated with longitudinal loss in quality of life, even after adjustment for progressive visual field loss. These findings suggest that rates of binocular RNFL change are valid markers for the degree of neural loss in glaucoma with significant relationship to glaucoma-associated disability.

A randomized control trial to evaluate the effect of adjuvant selective laser trabeculoplasty versus medication alone in primary open-angle glaucoma: preliminary results

Background

The objective of this study was to investigate the effects of adjuvant selective laser trabeculoplasty (SLT) versus medication alone on intraocular pressure (IOP) control, medication use, and quality of life in patients with primary open-angle glaucoma.

Methods

This prospective, randomized control study recruited 41 consecutive primary open-angle glaucoma subjects with medically-controlled IOP ≤21 mmHg. The SLT group (n=22) received a single 360-degree SLT treatment. The medication-only group (n=19) continued with their usual treatment regimen. In both groups, medication was titrated to maintain a target IOP defined as a 25% reduction from baseline IOP without medication, or <18 mmHg, whichever was lower. Outcomes, which were measured at baseline and at 6 months, included the Glaucoma Quality of Life-15 (GQL-15) and Comparison of Ophthalmic Medications for Tolerability (COMTOL) survey scores, IOP, and the number of antiglaucoma medicines.

Results

The baseline IOP was 15.8±2.7 mmHg and 14.5±2.5 mmHg in the SLT and medication-only groups, respectively (P=0.04). Both groups had a comparable number of baseline medication (P=0.2), GQL-15 (P=0.3) and COMTOL scores (P=0.7). At 6 months, the SLT group had a lower IOP (P=0.03) and required fewer medications compared with both baseline (P<0.0001) and with the medication-only group (P=0.02). There was no statistically significant difference in the 6-month GQL-15 or COMTOL score as compared to baseline (P≥0.4) or between the two treatment groups (P≥0.2).

Conclusion

A single session of adjuvant SLT provided further reductions in IOP and medication without substantial changes in quality of life or medication tolerability at 6 months.

Quality assessment of ophthalmic questionnaires: review and recommendations

PURPOSE

The aim of this article was to systematically review all the available ophthalmic patient-reported outcome (PRO) instruments (questionnaires) that demonstrated interval measurement properties to identify the instruments with the highest psychometric quality for use in different eye diseases and conditions.

METHODS

An extensive literature review was carried out to identify all existing ophthalmic PRO instruments. Instruments were then excluded if they did not have demonstrable interval measurement properties; the remaining instruments were reviewed. The quality of the following psychometric properties was assessed: content development (initial item development process), performance of the response scale, dimensionality (whether the instrument measures a single construct), measurement precision, validity (convergent, concurrent, discriminant, and known groups), reliability (test-retest), targeting (whether the items are appropriate [e.g., difficulty level] for the population), differential item functioning (whether subgroups of people respond differently to an item), and responsiveness.

RESULTS

The search identified 48 PRO instruments that demonstrated interval measurement properties, and these were relevant to nine applications: glaucoma, dry eye, refractive errors, cataract, amblyopia and strabismus, macular diseases, adult low vision, children low vision, and others. These instruments were evaluated against the psychometric property quality criteria and were rated for quality based on the number of criteria met.

CONCLUSIONS

This review provides a descriptive catalog of ophthalmic PRO instruments to inform researchers and clinicians on the choice of the highest-quality PRO instrument suitable for their purpose.

Dutch-Flemish translation of 17 item banks from the patient-reported outcomes measurement information system (PROMIS)

BACKGROUND

The Patient-Reported Outcomes Measurement Information System (PROMIS(®)) is a new, state-of-the-art assessment system for measuring patient-reported health and well-being of adults and children that has the potential to be more valid, reliable and responsive than existing PROMs. The PROMIS items can be administered in short forms or, more efficiently, through computerized adaptive testing. This paper describes the translation of 563 items from 17 PROMIS item banks (domains) for adults from the English source into Dutch-Flemish.

METHODS

The translation was performed by FACITtrans using standardized methodology and approved by the PROMIS Statistical Center. The translation included four forward translations, two back-translations, three to five independent reviews (at least two Dutch, one Flemish) and pre-testing in 70 adults (age range 20-77) from the Netherlands and Flanders.

RESULTS

A small number of items required separate translations for Dutch and Flemish: physical function (five items), pain behaviour (two items), pain interference (one item), social isolation (one item) and global health (one item). Challenges faced in the translation process included: scarcity or overabundance of possible translations, unclear item descriptions, constructs broader/smaller in the target language, difficulties in rank ordering items, differences in unit of measurement, irrelevant items or differences in performance of activities. By addressing these challenges, acceptable translations were obtained for all items.

CONCLUSION

The methodology used and experience gained in this study can be used as an example for researchers in other countries interested in translating PROMIS. The Dutch-Flemish PROMIS items are linguistically equivalent. Short forms will soon be available for use and entire item banks are ready for cross-cultural validation in the Netherlands and Flanders.

Comparison of resource utilization in the treatment of open-angle glaucoma between two cities in Finland: is more better?

INTRODUCTION

Glaucoma is a progressive optic neuropathy associated with neural rim loss of the optic disc and the retinal nerve fibre layer typically causing visual field (VF) deterioration. Generally, glaucomatous lesions in the eye and in the visual field progress slowly over the years. In population-based cross-sectional studies, the percentage of unilateral or bilateral visual impairment varied between 3-12%. In screening studies, 0.03-2.4% of patients have been found to suffer visual impairment. Glaucoma has previously been associated with substantial healthcare costs and resource consumption attributable to the treatment of the disease. The disease also causes reduction in health-related quality of life (HRQoL) in patients with glaucoma.

OBJECTIVE AND METHODS

This study compares patients with diagnosed open-angle glaucoma from two geographically different regions in Finland. A total of 168 patients were examined, 85 subjects from an area with higher per patient treatment costs (Oulu) and 83 patients from a region with lower per patient treatment costs (Turku). All patients had a history of continuous glaucoma medication use for a period of 11 years. For each patient, the total direct costs from glaucoma treatment were calculated and the total amount of resource consumption was determined from registries and patient records. Each patient underwent a clinical examination with visual field assessment and fundus photography. These data were used to determine the current stage of disease for each patient. Health-related quality of life questionnaire (15D) was used in determining each patient's subjective HRQoL score.

RESULTS

When applying the current diagnostic criteria for open-angle glaucoma, a total of 40% of patients did not to display any structural or functional damage suggesting glaucoma after 11 years of continuous medical treatment and follow-up. Patients with higher glaucoma stage (worse disease) were found to have statistically higher treatment costs compared with those at lower disease stages. Resource consumption was also greater in the patients in higher glaucoma stage. Patients in the Oulu district consumed more resources, and glaucoma treatment was more expensive than in the Turku area. The total treatment cost in Oulu and Turku was 6010 € and 4452 €, respectively, for the whole 11-year period. There was no statistically significant difference in quality-of-life scores between the two areas. No difference was noted between the higher-spending and lower-spending areas in this respect. However, when the population was analysed as a whole, patients with higher glaucoma stage were found to have lower vision-based 15D scores compared with those at lower disease stages. This observation was made also at both districts independently.

CONCLUSIONS

Major cost source in open-angle glaucoma treatment is medication, up to 74% of annual costs. In addition, it seems that higher resource consumption and higher treatment costs do not increase the patients' HRQoL as assessed by the 15D instrument.