Cat-PROM5: a brief psychometrically robust self-report questionnaire instrument for cataract surgery.

PurposeTo develop a short, psychometrically robust and responsive cataract patient reported outcome measure suitable for use in high-volume surgical environments.MethodsA prospective study in which participants completed development versions of questionnaires exploring the quality of their eyesight using items harvested from two existing United Kingdom developed parent questionnaires. Participants were 822 patients awaiting cataract surgery recruited from 4 cataract surgical centres based in the UK. Exclusion criteria were other visually significant comorbidities and age <50 years. An iterative multi-stage process of evaluation using Rasch and factor analyses with sequential item reduction was undertaken.ResultsA definitive item set of just five items delivered performance in accordance with the requirements of the Rasch model: no threshold disordering, no misfitting items, Rasch-based reliability 0.90, person separation 2.98, Cronbach's α 0.89, good targeting of questions to patients with cataract with pre-operative item mean -0.41 logits and absence of significant floor or ceiling effects, minor deviations of item invariance, and confirmed unidimensionality. The test-re-test repeatability intra-class correlation coefficient was 0.89 with excellent responsiveness to surgery, Cohen's d -1.45 SD. Rasch calibration values are provided for Cat-PROM5 users.ConclusionsA psychometrically robust and highly responsive five-item cataract surgery patient reported outcome measure has been developed, which is suitable for use in high-volume cataract surgical services.

Cataract surgery patient-reported outcome measures: a head-to-head comparison of the psychometric performance and patient acceptability of the Cat-PROM5 and Catquest-9SF self-report questionnaires.

Background Cataract surgery is the most frequently undertaken NHS surgical procedure. Visual acuity (VA) provides a poor indication of visual difficulty in a complex visual world. In the absence of a suitable outcome metric, recent efforts have been directed towards the development of a cataract patient-reported outcome measure (PROM) of sufficient brevity, precision, and responsiveness to be implementable in routine high volume clinical services.Aim To compare and contrast the two most promising candidate PROMs for routine cataract surgery.Method The psychometric performance and patient acceptability of the recently UK developed five-item Cat-PROM5 questionnaire was compared with the English translation of the Swedish nine-item Catquest-9SF using Rasch-based performance metrics and qualitative semistructured interviews.Results Rasch-based performance was assessed in 822 typical NHS cataract surgery patients across four centres in England. Both questionnaires demonstrated good to excellent performance for all metrics assessed, including Person Reliability Indices of 0.90 (Cat-PROM5) and 0.88 (Catquest-9SF), responsiveness to surgery (Cohen's standardized effect size) of 1.45 SD (Cat-PROM5) and 1.47 SD (Catquest-9SF) and they were highly correlated with each other (R=0.85). Qualitative assessments confirmed that both questionnaires were acceptable to patients, including in the presence of ocular comorbidities. Preferences were expressed for the shorter Cat-PROM5, which allowed patients to map their own issues to the questions as opposed to the more restrictive specific scenarios of Catquest-9SF.Conclusion The recently UK developed Cat-PROM5 cataract surgery questionnaire is shorter, with performance and patient acceptability at least as good or better than the previous 'best of class' Catquest-9SF instrument.

Cost effectiveness of collagen crosslinking for progressive keratoconus in the UK NHS.

BACKGROUND: Keratoconus is a progressive degenerative corneal disorder of children and young adults that is traditionally managed by refractive error correction, with corneal transplantation reserved for the most severe cases. UVA collagen crosslinking is a novel procedure that aims to prevent disease progression, currently being considered for use in the UK NHS. We assess whether it might be a cost-effective alternative to standard management for patients with progressive keratoconus. METHODS: We constructed a Markov model in which we estimated disease progression from prospective follow-up studies, derived costs derived from the NHS National Tariff, and calculated utilities from linear regression models of visual acuity in the better-seeing eye. We performed deterministic and probabilistic sensitivity analyses to assess the impact of possible variations in the model parameters. RESULTS: Collagen crosslinking is cost effective compared with standard management at an incremental cost of £ 3174 per QALY in the base case. Deterministic sensitivity analysis shows that this could rise above £ 33,263 per QALY if the duration of treatment efficacy is limited to 5 years. Other model parameters are not decision significant. Collagen crosslinking is cost effective in 85% of simulations at a willingness-to-pay threshold of £ 30,000 per QALY. CONCLUSION: UVA collagen crosslinking is very likely to be cost effective, compared with standard management, for the treatment of progressive keratoconus. However, further research to explore its efficacy beyond 5 years is desirable.

Comparison of the ETDRS logMAR, 'compact reduced logMar' and Snellen charts in routine clinical practice.

AIM: To compare the performance of the ETDRS logMAR, compact reduced logMAR and Snellen charts in an ophthalmic outpatient setting. METHODS: The reliability and reading times of the charts were compared in a stratified sample of 40 eyes of 40 ophthalmic patients with a variety of stable eye diseases. In order to simulate a clinical setting, forced-choice testing was not used. RESULTS: Similar acuity results were recorded from all three charts, suggesting a lack of a systematic bias as regards chart design. A small practice effect was observed for all charts but was greatest for Snellen and least for ETDRS. The test-retest variability of the charts was similar, with the 95% tolerance limit for change being +/-0.14 logMAR for ETDRS, +/-0.16 for reduced logMAR and +/-0.18 for Snellen. The mean reading times for the subjects were 34.65 s for ETDRS, 21.17 s for reduced logMAR and 18.67 s for Snellen. CONCLUSION: The performance of the compact reduced logMAR chart was intermediate between Snellen and ETDRS. The theoretical advantages of the ETDRS design were still measurable in a clinical setting but the magnitude of the advantage in terms of test-retest reliability was fairly small and the time taken to complete the EDTRS was 1.86 times that of the Snellen chart.

Risk factors for cataract subtypes waterclefts and retrodots: two case-control studies.

UNLABELLED: Waterclefts and retrodots are independently associated with visual impairment, yet a review identified no data on risk factors. PURPOSE: To investigate risk factors for these two human lens cataract subtypes. METHOD: Two nested case-control studies: The host study comprised 1078 subjects (55 years) attending the Somerset and Avon Eye Study (SAES). In total, 197 watercleft cases (Oxford grade 0.2 in either eye) and 199 retrodot cases (Oxford grade 1.0 in either eye) were individually age/gender matched to controls. Detailed ophthalmic and potential risk factor data were collected, including body mass index (BMI), smoking, alcohol, diabetes, hypertension, analgesics, vitamin supplementation, nutrition, sunlight exposure, dehydration, hormonal (women), blood lipids, glucose, urea, creatinine, uric acid, and vitamin levels. RESULTS: For waterclefts, univariable analysis identified BMI, alcohol intake, vitamin status, sunlight, urea, creatinine, and uric acid as possible risk factors. Multivariable analysis identified two independent associations. Total number of 'any' analgesics in the previous year: adjusted P<0.01 (U-shaped risk profile, unadjusted high vs medium use (=reference) OR 2.39, 95% CI 1.35-4.26 with medium use vs none (=reference) OR 0.43, 95% CI 0.26-0.72); total sunlight: adjusted P=0.03 (unadjusted highest exposure vs lowest (=reference) OR 3.25, 95% CI 1.11-9.50). For retrodots, univariable analysis identified alcohol, HRT, and lipids. Multivariable analysis identified two independent associations. Mean number of alcohol units consumed per month, adjusted P=0.02 and HDL cholesterol levels, adjusted P=0.02 (unadjusted ORs NS both). CONCLUSION: This is the first available published information on risk factors for the human cataractous lens features waterclefts and retrodots.

Quality of life and visual function in patients with intermediate uveitis.

AIMS: To assess visual function, vision related quality of life (VR-QOL), and general health related quality of life (HR-QOL) in intermediate uveitis (IU). METHODS: VR-QOL and HR-QOL were evaluated in 42 patients with IU using the VCM1 and SF-36 questionnaires, respectively. LogMAR visual acuity (VA), Pelli-Robson contrast sensitivity (CS), Farnsworth-Munsell 100 hue colour vision (CV), and Estermann visual field (VF) were recorded monocularly and binocularly. RESULTS: Median (interquartile range) visual acuity (VA) and CS of 72 affected eyes were 0.1 (0.015-0.3) and 1.55 (1.35-1.65), respectively. 9.5% of patients had a VCM1 score of more than 2.0, indicating "more than a little" concern over vision. Worse eye VA (p=0.045) and CS (p=0.042) were predictive of a VCM1 score of more than 2.0 independently of age, sex, uveitis duration, laterality and activity, systemic uveitis therapy, and medical co-morbidity. The physical and mental component summary scores of the SF-36 were significantly worse in those who reported significant impairment of vision on the VCM1 than those who did not. CONCLUSIONS: The majority of patients with IU maintain good visual function and quality of life. VR-QOL impairment in IU correlates with vision in the worse eye and is associated with impaired HR-QOL.

The Bristol cataract listing survey: profile of listed patients with visual acuity 6/12 or better.

INTRODUCTION: The aim of this study was to assess the vision-related quality of life (VR-QOL) in patients with good distance Snellen visual acuity (VA) who are listed for cataract surgery. METHODS: An observational cross-sectional prospective study of patients listed for cataract surgery. VA and VR-QOL data using the VCMI questionnaire were collected on patients attending preoperative assessment during June 2002. RESULTS: A total of 397 cataract patients were listed during this month. Following exclusions there were 378 eligible individuals, 210 (56%) of whom had a VA of 6/12 or better in the eye scheduled for surgery. Of these, 40% patients had only mild VR-QOL impairment. More than half of the patients with good VA (6/12 or better) in the surgery eye and mild VR-QOL impairment described their vision as poor in this eye. However, most of these patients were not dissatisfied with their overall level of vision. CONCLUSION: A significant number of patients listed for cataract surgery with VA of 6/12 or better had only mild VR-QOL impairment and were not dissatisfied with their overall level of vision. The decision to list a patient for surgery may have been based on the patient's perception of monocular vision rather than their quality of life.

Reliability of the VCM1 Questionnaire when administered by post and by telephone.

PURPOSE: To assess the reliability of different methods of administration of the VCM1 vision-related quality-of-life questionnaire by: a) comparing responses obtained by post to responses obtained in a research clinic and b) comparing responses obtained by telephone to responses obtained in a research clinic. METHOD: Questionnaire responses given in advance by post (96 subjects) or by telephone (92 subjects) were compared to those subsequently given at a visit to a research clinic. The questionnaire included the VCM1 and two other questions commonly used in surveys of visual impairment (reading small print and recognising a face across the street). RESULTS: Similar levels of vision-related quality-of-life (VR-QOL) impairment were reported by post and in the research clinic. However, the participants in the telephone test group reported less VR-QOL impairment by telephone than they subsequently reported in the clinic (P = 0.0001). The mean score difference between telephone and clinic administration was 3.2% of the VCM1 questionnaire scale. Lower social class (P = 0.002) and increasing duration of interview (P = 0.003) were associated with a tendency to under-report VR-QOL impairment by telephone. Interference with reading small print (P = 0.0001) and recognising a face across the street (P = 0.0001) were also under-reported by telephone. CONCLUSIONS: Telephone interviewing caused a general bias towards under-reporting of visual problems which was not confined to the VCM1. Care is required when planning outcome studies and questionnaire surveys to ensure that different methods of questionnaire administration produce comparable results.

The assessment of lens opacities in clinical practice: results of a national survey.

AIM: To investigate the examination of lens opacities in routine ophthalmic clinical practice. METHOD: A questionnaire survey was mailed to 703 consultant ophthalmologists in the UK. The surgeons were asked which lens feature(s) they assessed in their clinics when deciding whether to offer cataract surgery. RESULTS: 489 replies were received. A broad range of lens opacities was assessed, with differences between surgeons for some opacities with high prevalences in the population, particularly cortical opacities. Many (74% of 467) surgeons assessed one or more lens opacities (anterior subcapsular cataract, vacuoles, water clefts, coronary flakes, focal dots, retrodots, fibre folds) which may be visually important but which have received relatively little attention by researchers. CONCLUSIONS: Some classes of lens opacity which are traditionally measured by researchers may be ignored in clinical practice and opacities which are traditionally ignored by some researchers are regarded as clinically important by a substantial number of surgeons.

Visual function and subjective quality of life compared in subjects with acquired macular disease.

PURPOSE: To determine the objective measures of visual function that are most relevant to subjective quality of vision and perceived reading ability in patients with acquired macular disease. METHODS: Twenty-eight patients with macular disease underwent a comprehensive assessment of visual function. The patients also completed a vision-related quality-of-life questionnaire that included a section of general questions about perceived visual performance and a section with specific questions on reading. RESULTS: Results of all tests of vision correlated highly with reported vision-related quality-of-life impairment. Low-contrast tests explained most of the variance in self-reported problems with reading. Text-reading speed correlated highly with overall concern about vision. CONCLUSIONS: Reading performance is strongly associated with vision-related quality of life. High-contrast distance acuity is not the only relevant measure of visual function in relation to the perceived visual performance of a patient with macular disease. The results suggest the importance of print contrast, even over print size, in reading performance in patients with acquired macular disease.

Use of vision tests in clinical decision making about cataract surgery: results of a national survey.

AIM: To provide information on the use of vision tests in clinical decision making about cataract surgery in the UK. METHOD: A questionnaire survey was mailed to 703 consultant ophthalmologists. RESULTS: A response rate of 70% was obtained. Monocular distance visual acuity was the only visual function that was tested routinely by all surgeons. Supplementary use of contrast sensitivity and glare testing was low. Many surgeons (35%) were willing to consider surgery at acuity levels better than 6/9 and a small but substantial number (12%) indicated that they did not use an acuity criterion. Being prepared to consider surgery at relatively good levels of acuity was not associated with more common use of other tests of vision. CONCLUSION: Many UK surgeons are prepared to consider cataract extraction at relatively good levels of visual acuity and use other vision tests infrequently.

Decimalization of The Oxford Clinical Cataract Classification and Grading System.

BACKGROUND: A secure methodology for the classification of cataracts into subtypes and for their separate quantification forms a fundamental underpinning of cataract research. The Oxford Clinical Cataract Classification and Grading System provides for this need across a wide range of cataract subtypes. Consideration of the advantages of finer scale intervals in terms of both increased precision and increased sensitivity to change (responsiveness) has stimulated the development of a decimal version of the Oxford system. AIM: To describe rules for the decimalization of the Oxford system and to document the performance following decimalization. METHOD: Theoretical considerations followed by iterative piloting were used to define a set of rules for the decimalization of grading for 10 cataract features. The performance of the decimal version was then formally tested by means of inter- and intra-observer comparisons of repeated measurements. 217 paired observations were pooled to produce a statement relevant to the 'multi-user' environment typical of many clinical research programmes. RESULTS: Repeatability indices were good to excellent for most features. The use of finer scale intervals improved the system's ability to detect change (reduced 95% tolerance limits for change) by a factor of around 2 for most features. CONCLUSION: The finer scale intervals provided by decimalization of the Oxford system have produced substantial improvements in reliability as evidenced by high levels of repeatability and scale sensitivity. These improvements provide practical advantages in clinical cataract research.

Development of a questionnaire for measurement of vision-related quality of life.

PURPOSE: To define vision-related quality of life, to outline the development of a vision-specific quality of life instrument and to present the characteristics of a 10-item 'core' questionnaire. METHOD: A standard method included: 1. Generation of relevant issues by individual interviews with 38 visually impaired adults, consultation with 37 professionals and support workers and literature review. 2. Operationalisation, involving 58 ophthalmic patients. 3. Pre-testing, to maximise face validity and content validity, involving 184 individuals with a variety of different visual problems and social backgrounds. 4. Adoption of a modular approach to item selection. 5. Formal piloting in 92 individuals to establish reliability and construct validity. RESULTS: More than 232 items were tested of which 139 were considered suitable for a final question pool or 'parent' questionnaire (the VQOL). From this parent questionnaire individual items or groups of items can be selected. Ten broadly applicable items referring to physical, social and psychological issues were selected for the core questionnaire (the VCM1). The VCM1 has high reliability (alpha = 0.93) and validity. CONCLUSIONS: Any self-reported problem relating to vision may constitute a quality of life issue. A modular approach to item selection may provide the flexibility to investigate vision-related quality of life in a wide range of clinical settings, allowing detailed assessment of specific problems and also cross-study comparisons where appropriate.

Iris dialysis and retinal dialysis caused by coin throwing.

A 13-year old boy was hit in the right eye by a coin that was thrown at him. He presented to the accident and emergency (A&E) department with an oblique corneal abrasion, microscopic hyphaema, iris-ciliary body dialysis, commotio retinae with retinal haemorrhages and a large retinal dialysis. The limited amount of available data in the medical literature suggests that eye injuries as a result of coin throwing are serious and should always be referred to an ophthalmologist for evaluation.

Vitreous loss in planned extracapsular cataract extraction does lead to a poorer visual outcome.

Forty-six cases of vitreous loss during planned extracapsular cataract extraction salvaged by anterior vitrectomy and primary anterior chamber lens implantation were compared in a retrospective cohort study with 92 individually matched controls. The postoperative visual outcome for cases with vitreous loss was significantly poorer than that for controls even after adjustment for confounding variables. Part of this visual morbidity was explained by cystoid macular oedema and retinal detachment, but even after adjusting for these two complications visual outcome remained worse among cases than controls. There was a significantly higher incidence of clinically apparent cystoid macular oedema amongst cases compared with controls (20% versus 1%). Two retinal detachments occurred among the cases but this difference in incidence was not statistically significant.

Idiopathic polymyositis complicated by arthritis and mesangial proliferative glomerulonephritis: case report and review of the literature.

A 56-yr-old male developed a systemic illness while receiving cyclical oral etidronate therapy for idiopathic osteoporosis. The illness, characterized by fever, proximal myopathy and inflammatory synovitis, was associated with interstitial lung disease and mesangial proliferative glomerulonephritis. Elevated plasma creatine phosphokinase level and inflammatory muscle biopsy findings confirmed a diagnosis of polymyositis (PM). Antibodies to Jo-1 were also detected. A review of the literature reveals that mesangial proliferation is the commonest glomerular lesion and suggests a possible association between arthritis and glomerulonephritis in PM. The prognosis of this renal lesion appears to be good, although only limited data is available.