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Biomedical subjects

N A Frost

Publications and source records attributed to N A Frost.

18 recordsLinked to original sources
PubMed2005

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.

Aged↗
PubMed2005

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.

Aged↗
PubMed2005

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.

Adult↗
PubMed2001

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.

Age Distribution↗
PubMed2001

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.

Cataract↗
PubMed2000

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.

Aged↗
PubMed2000

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.

Cataract↗
PubMed2000

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.

Adult↗
PubMed1998

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.

Adult↗
PubMed1995

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.

Aged↗
PubMed1995

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.

Adolescent↗
PubMed1993

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.

Arthritis↗
PubMed1991

Symptomatic intraventricular xanthogranulomata. A report of 2 cases.

Intraventricular xanthogranulomata may occasionally be seen as incidental findings at post-mortem. It is however, exceptionally rare for them to become symptomatic, but if they do, it is usually attributable to obstruction of the CSF pathways. Two further symptomatic cases are presented and the literature is reviewed. Treatment is surgical excision, but stereotactic biopsy should be avoided due to the often impenetrable nature of the capsule.

Adult↗