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Biomedical subjects

P M Hart

Publications and source records attributed to P M Hart.

At least 19 recordsLinked to original sources
PubMed2005

Visual functioning and quality of life in the SubFoveal Radiotherapy Study (SFRADS): SFRADS report 2.

AIMS: To determine whether or not self reported visual functioning and quality of life in patients with choroidal neovascularisation caused by age related macular degeneration (AMD) is better in those treated with 12 Gy external beam radiotherapy in comparison with untreated subjects. METHODS: A multicentre single masked randomised controlled trial of 12 Gy of external beam radiation therapy (EBRT) delivered as 6 x 2 Gy fractions to the macula of an affected eye versus observation. Patients with AMD, aged 60 years or over, in three UK hospital units, who had subfoveal CNV and a visual acuity equal to or better than 6/60 (logMAR 1.0). METHODS: Data from 199 eligible participants who were randomly assigned to 12 Gy teletherapy or observation were available for analysis. Visual function assessment, ophthalmic examination, and fundus fluorescein angiography were undertaken at baseline and at 3, 6, 12, and 24 months after study entry. To assess patient centred outcomes, subjects were asked to complete the Daily Living Tasks Dependent on Vision (DLTV) and the SF-36 questionnaires at baseline, 6, 12, and 24 months after enrolment to the study. Cross sectional and longitudinal analyses were conducted using arm of study as grouping variable. Regression analysis was employed to adjust for the effect of baseline co-variates on outcome at 12 months and 24 months. RESULTS: Both control and treated subjects had significant losses in visual functioning as seen by a progressive decline in mean scores in the four dimensions of the DLTV. There were no statistically significant differences between treatment and control subjects in any of dimensions of the DLTV at 12 months or 24 months after study entry. Regression analysis confirmed that treatment status had no effect on the change in DLTV dimensional scores. CONCLUSIONS: The small benefits noted in clinical measures of vision in treated eyes did not translate into better self reported visual functioning in patients who received treatment when compared with the control arm. These findings have implications for the design of future clinical trials and studies.

Activities of Daily Living↗
PubMed2005

Further validation of the Daily Living Tasks Dependent on Vision: identification of domains.

AIM: To examine the Daily Living Tasks Dependent on Vision (DLTV), a visual function questionnaire for domain structure, and redundancy. METHOD: 235 subjects underwent full ophthalmic assessment and completed the DLTV questionnaire by interview. Principal component analysis with varimax rotation and item response theory (IRT) were used to assign the items to domains. The internal consistency of each domain was examined using Cronbach's alpha. Redundancy was assessed by regressing each item in a domain against the remainder of items in that domain. RESULTS: Four domains were identified. Domain 1 was formed by nine items, which after applying IRT were seen to be among the most difficult questions in the instrument. Domain 2 contained eight items, all of which fell in the easier half of the instrument on applying IRT. Domain 3 contained only three items, all of which were among the easier questions and appear to deal with peripheral vision function. Domain 4 consisted of two items dealing with adaptation to light and dark conditions. Cronbach's alpha for each domain was 0.96, 0.93, 0.73, 0.66. Redundancy was found to be present in domain 1, which was therefore reduced by two items, with little effect on internal consistency. CONCLUSIONS: The authors believe using the domains identified in this report will optimise the information provided by patients on their ability to function on visually demanding tasks.

Activities of Daily Living↗
PubMed2004

Reduced vision in older adults with age related macular degeneration interferes with ability to care for self and impairs role as carer.

AIM: To study the relation between visual impairment and ability to care for oneself or a dependant in older people with age related macular degeneration (AMD). METHOD: Cross sectional study of older people with visual impairment due to AMD in a specialised retinal service clinic. 199 subjects who underwent visual function assessment (fully corrected distance and near acuity and contrast sensitivity in both eyes), followed by completion of a package of questionnaires dealing with general health status (SF36), visual functioning (Daily Living Tasks Dependent on Vision, DLTV) and ability to care for self or provide care to others. The outcome measure was self reported ability to care for self and others. Three levels of self reported ability to care were identified--inability to care for self (level 1), ability to care for self but not others (level 2), and ability to care for self and others (level 3). RESULTS: People who reported good general health status and visual functioning (that is, had high scores on SF36 and DLTV) were more likely to state that they were able to care for self and others. Similarly people with good vision in the better seeing eye were more likely to report ability to care for self and others. People with a distance visual acuity (DVA) worse than 0.4 logMAR (Snellen 6/15) had less than 50% probability of assigning themselves to care level 3 and those with DVA worse than 1.0 logMAR (Snellen 6/60) had a probability of greater than 50% or for assigning themselves to care level 1. Regression analyses with level of care as the dependent variable and demographic factors, DLTV subscales, and SF36 dimensions as the explanatory variables confirmed that the DLTV subscale 1 was the most important variable in the transition from care level 3 to care level 2. The regression analyses also confirmed that the DLTV subscale 2 was the most important in the transition from care level 3 to care level 1. CONCLUSIONS: Ability to care for self and dependants has a strong relation with self reported visual functioning and quality of life and is adversely influenced by visual impairment. The acuity at which the balance of probability shifts in the direction of diminished ability to care for self or others is lower than the level set by social care agencies for provision of support. These findings have implications for those involved with visual rehabilitation and for studies of the cost effectiveness of interventions in AMD.

Activities of Daily Living↗
PubMed2002

Visual outcomes in the subfoveal radiotherapy study: a randomized controlled trial of teletherapy for age-related macular degeneration.

OBJECTIVE: To determine whether teletherapy with 6-mV photons can reduce visual loss in patients with subfoveal choroidal neovascularization in age-related macular degeneration. DESIGN: A multicenter, single-masked, randomized controlled trial of 12 Gy of external beam radiation therapy delivered to the macula of an affected eye vs observation only. SETTING: Three United Kingdom-based hospital units. PARTICIPANTS: Patients with age-related macular degeneration, aged 60 years and older, who had subfoveal choroidal neovascularization and a visual acuity of 20/200 (logMAR 1.0) or better. METHODS: Two hundred three patients were randomly assigned to radiotherapy or observation. Treatment was undertaken at designated radiotherapy centers, and patients assigned to the treatment group received a total dosage of 12 Gy of 6-mV photons in 6 fractions. Follow-up was scheduled at 3, 6, 12, and 24 months. After excluding protocol violators, the data from 199 patients were analyzed. MAIN OUTCOME MEASURES: The primary outcome measure was mean loss of distance visual acuity in the study eye at 12 and 24 months. Other outcome variables analyzed were near visual acuity and contrast sensitivity. The proportions of patients losing 3 or more or 6 or more lines of distance and near acuity and 0.3 or more or 0.6 or more log units of contrast sensitivity at each follow-up were also analyzed. RESULTS: At all time points, mean distance visual acuity was better in the radiotherapy-treated group than in the control group, but the differences did not reach statistical significance. At 24 months, analysis of the proportions of patients with loss of 3 or more (moderate) (P =.08) or 6 or more (severe) (P =.29) lines of distance vision showed that fewer treated patients had severe losses, but there was no statistically significant difference between groups. For near visual acuity, although there was no evidence of treatment benefit at 12 and 24 months, a significant difference in favor of treatment was present at 6 months (P =.048). When analyzed by the proportions of patients losing 3 lines of contrast sensitivity, there was a significant difference in favor of treatment at 24 months (P =.02). No adverse retinal effects were observed during the study, but transient disturbance of the precorneal tear film was noted in treated patients. CONCLUSION: The results of the present trial do not support the routine clinical use of external beam radiation therapy in subjects with subfoveal choroidal neovascularization in age-related macular degeneration.

Aged↗
PubMed2001

Improvements in measures of vision and self-reported visual function after cataract extraction in patients with late-stage age-related maculopathy.

PURPOSE: A recent study indicated that patients with cataracts and early age-related maculopathy may benefit from cataract extraction. To ascertain whether cataract extraction in the presence of concurrent advanced age-related maculopathy was also associated with a clear benefit, we studied visual function and self-reported visual functioning in a cohort of 12 patients pre- and post-phakoemulsification. METHODS. All 12 patients had a diagnosis of advanced age-related maculopathy in the eye scheduled for cataract surgery. Preoperative assessment included refraction and recording of best corrected distance and near acuity and contrast sensitivity in both eyes. The Daily Living Tasks Dependent on Vision questionnaire was administered. After phakoemulsification and intraocular lens implantation, all patients were reviewed and assessed. RESULTS: After surgery, improvement in acuity was recorded in nine operated eyes, whereas acuity remained unchanged in three eyes. Improvement in contrast sensitivity in the operated eye occurred in 10 patients, but in two patients contrast was reduced postoperatively. In terms of self-reported visual functioning, improvement in the ability to undertake many daily living tasks dependent on vision was recorded after cataract surgery. CONCLUSIONS: Significant improvements in specific areas of self-reported visual functioning and measures of vision were recorded after cataract surgery. During the follow-up period, none of the operated eyes suffered a fall in visual acuity. There was also no evidence of worsening of the pre-existing macular lesion as judged by clinical examination and fundus photography.

Aged↗
PubMed2001

Relation between macular morphology and visual function in patients with choroidal neovascularisation of age related macular degeneration.

AIM: To examine the relation between three measures of visual function (distance acuity, near acuity, and contrast sensitivity) and specific fluorescein angiographic characteristics of the macular lesion in patients with subfoveal choroidal neovascularisation (CNV) due to age related macular degeneration (AMD). METHODS: Visual evaluation and digital fundus fluorescein angiography were performed in 93 patients with subfoveal CNV. Standard morphometric techniques were used on two frames from the angiographic series closest to 30 seconds and 60 seconds respectively, to ascertain total lesion size (defined as the entire area of abnormal fluorescence), the size of the classic component, and the distance from the fovea to the closest point of healthy retina. Correlations were sought using Pearson's correlation coefficients. Stepwise regression was used to minimise multiple colinearity. RESULTS: When the study eye was the better eye of a patient's pair of eyes, the strongest correlation was between the size of the classic component and contrast sensitivity (r= 0.48, p <0.001) and was highly significant. When the study eye was the worse eye, significant correlations were observed between total lesion size and all three measures of visual function. The strongest correlation was observed between overall lesion size and contrast sensitivity (r = 0.52, p <0.001). CONCLUSIONS: This study has shown that the status of the study eye (that is, better or worse eye of a pair of eyes) influences the impact of macular pathology in AMD on visual function. The distance of the fovea from healthy retina was found to be an important factor in predicting visual function.

Aged↗
PubMed2000

Macular degeneration: do conventional measurements of impaired visual function equate with visual disability?

AIMS: To examine the relation between measures of vision and ability to perform daily living tasks in those visually impaired with macular degeneration. METHODS: A visual functioning index (daily living tasks dependent on vision: DLTV) was used to evaluate patients' perception of their ability to perform vision dependent tasks. Distance visual acuity, near visual acuity, reading speed, and contrast sensitivity were measured in all patients. In addition, a new measure of reading ability was derived, designated the reading index. This takes into account both the size of the text read and the time to read it and is equivalent to the reading speed in words per minute divided by text size in M. RESULTS: The reading index was found to show best associations with the majority of items within the DLTV. Stepwise regression identified the combination of reading index and distance visual acuity as having the best associations with DLTV items. The present study also demonstrated that specific levels of vision as measured by acuity, reading index, and contrast sensitivity corresponded with different perceived amounts of difficulty in the performance of daily living tasks. CONCLUSIONS: This study showed that reading index is valuable in predicting the ability to perform daily living tasks and therefore may be useful in the visual assessment of the visually impaired individual. In addition, this study identified specific levels of vision at which individuals reported different degrees of difficulty in performing daily living tasks.

Activities of Daily Living↗
PubMed2000

Amblyopia: is visual loss permanent?

AIM: To ascertain whether recovery of visual function in amblyopic eyes is likely to occur when the fellow eye is lost as a result of age related macular degeneration. METHODS: The records of 465 patients with an established diagnosis of age related macular degeneration who had attended a specialist macular clinic between 1990 and 1998 were scrutinised. A full clinical examination and standardised refraction had been carried out in 189 of these cases on a minimum of two occasions. Cases were looked for where an improvement of one or more lines of either distance or near acuity was recorded in the eye unaffected by macular disease. In each one of these cases the improvement in visual acuity could not be attributed to treatment of other existing pathology. RESULTS: 12 such cases were detected. In nine of these the eye showing improvement of acuity had a history of amblyopia. The mean improvement in distance and near acuity in amblyopic eyes by 12 months was 3.3 and 1.9 lines logMAR respectively. The improvement in acuity generally occurred between 1 and 12 months from baseline and remained stable over the period of follow up. CONCLUSIONS: Older people with a history of amblyopia who develop visual loss in the previously normal eye can experience recovery of visual function in the amblyopic eye over a period of time. This recovery in visual function occurs in the wake of visual loss in the fellow eye and the improvement appears to be sustained.

Amblyopia↗
PubMed2000

Development of the school organisational health questionnaire: a measure for assessing teacher morale and school organisational climate.

BACKGROUND: A growing body of empirical evidence suggests that organisational factors are more important than classroom specific issues in determining teacher morale. Accordingly, it is necessary to have available measures that accurately assess morale, as well as the organisational factors that are likely to underpin the experience of morale. AIM: Three studies were conducted with the aim of developing a psychometrically sound questionnaire that could be used to assess teacher morale and various dimensions of school organisational climate. SAMPLE: A total of 1,520 teachers from 18 primary and 26 secondary schools in the Australian state of Victoria agreed to participate in three separate studies (N = 615, 342 and 563 in Studies 1, 2 and 3, respectively) that were used to develop the questionnaire. The demographic profile of the teachers was similar to that found in the Department as a whole. METHOD: All teaching staff in the participating schools were asked to complete a self-report questionnaire as part of the evaluation of an organisational development programme. RESULTS: A series of exploratory and confirmatory factor analyses were used to establish the questionnaire's factor structure, and correlation analyses were used to examine the questionnaire's convergent and discriminant validity. CONCLUSIONS: The three studies resulted in the 54-item School Organisational Health Questionnaire that measures teacher morale and 11 separate dimensions of school organisational climate: appraisal and recognition, curriculum coordination, effective discipline policy, excessive work demands, goal congruence, participative decision-making, professional growth, professional interaction, role clarity, student orientation, and supportive leadership.

Adolescent↗
PubMed1999

Dinucleotide repeat polymorphisms in EDN1 and NOS3 are not associated with severe diabetic retinopathy in type 1 or type 2 diabetes.

PURPOSE: Endothelin-1, and constitutive endothelial nitric oxide synthase, have been implicated in the pathogenesis of diabetic retinopathy. We therefore screened polymorphisms within the genes encoding these two vasoactive agents in a sample of individuals with 15 years of diabetes and no retinopathy (ETDRS level 10 or better) and those with severe retinopathy (ETDRS level 50 or worse). METHODS: PCR primers for highly polymorphic sites within the EDN1 and NOS3 genes were used to genotype individuals with type 1 or type 2 diabetes with severe or no retinopathy. Allele frequencies were compared between groups using chi-squared analysis and adjusting for multiple comparisons. RESULTS: No significant differences were observed in allele frequencies for these two markers between the patients who had retinopathy and the patients who did not. CONCLUSION: Polymorphic variability in the EDN1 and NOS3 genes does not appear to have a major impact on determining susceptibility or resistance to diabetic retinopathy.

Adult↗
PubMed1999

Genotyping and functional analysis of a polymorphic (CCTTT)(n) repeat of NOS2A in diabetic retinopathy.

Accumulating evidence shows that the severity and rapidity of onset of diabetic retinopathy are influenced by genetic factors. Expression of the nitric oxide synthases is altered in the retinal vasculature in the early stages of diabetic retinopathy. We analyzed the allele distribution of a polymorphic pentanucleotide repeat within the 5' upstream promoter region of the NOS2A gene in samples of diabetic patients. In diabetic patients from Northern Ireland, the 14-repeat allele of the NOS2A marker was significantly associated with the absence of diabetic retinopathy. Carriers of this repeat had 0.21-fold the relative risk of developing diabetic retinopathy than noncarriers of this allele. They also had significantly fewer renal and cardiovascular complications. The ability of differing numbers of (CCTTT)(n) pentanucleotide repeats to induce transcription of the NOS2A gene was analyzed using a luciferase reporter gene assay in transfected colonic carcinoma cells. Interleukin 1beta (IL-1beta) induction was most effective in constructs carrying the 14-repeat allele. When cells were incubated in 25 mM glucose to mimic the diabetic state, IL-1beta induction was inhibited in all cases, but to a significantly lesser extent with the 14-repeat allele. These unique properties of the 14-repeat allele may confer selective advantages in diabetic individuals, which may delay or prevent microvascular complications of diabetes.

Adult↗
PubMed1999

A vision specific functional index for use in patients with age related macular degeneration.

AIM: To develop and evaluate a new vision specific functional index for use in individuals with age related macular degeneration (AMD). METHODS: Following consultation with patients with AMD and healthcare professionals, a questionnaire entitled the Daily Living Tasks Dependent on Vision (DLTV) was constructed. It was administered by interview to three separate groups of individuals aged 50 years or older: people with AMD, people with cataract, and people with no visual disability. The relations between DLTV, distance visual acuity, and disorder were examined using Pearson's product moment correlation coefficients, stepwise regression, and principal component analysis. RESULTS: There was a positive correlation between DLTV items and distance visual acuity in the better eye. Principal component analysis showed that the DLTV has a major single dimension within it. This first principal component accounted for 59% of the variation and correlated well with distance visual acuity in the better eye. Other components were found, one of which correlated with the difference in vision in the two eyes and one which featured in the differentiation of AMD subjects from individuals with cataracts. CONCLUSIONS: The DLTV provided information on visual impairment in patients over and above that obtained from a measure of visual acuity. It also showed that patients with AMD experience greater difficulty with daily living tasks for any given level of acuity than do patients with cataract.

Activities of Daily Living↗
PubMed1998

Questionnaire-based survey on the importance of quality of life measures in ophthalmic practice.

PURPOSE: To assess the awareness of the existence of quality of life (QOL) instruments and their perceived relative merit in the management of various eye conditions among ophthalmologists in the United Kingdom. METHODS: A self-administered questionnaire was circulated among various grades of ophthalmologists attending a major UK ophthalmology conference. The respondents were asked to rank from a list in order of importance various tests of visual function in different ophthalmic conditions. RESULTS: Distance and near visual acuity were consistently rated high with mean ranks lower than 4.0. Contrast sensitivity and reading speed were consistently rated as low in importance with mean ranks ranging from 4 to 5.8. QOL instruments were deemed to be of some importance in the management of cataract and to a lesser extent in the management of age-related macular degeneration. Only 2 respondents of 36 could name either a generic or a vision-specific QOL instrument. CONCLUSION: UK ophthalmologists appear to be unfamiliar with QOL measures, despite the fact that in health economics they have become the standard means of assessing the results of health care interventions and of prioritizing funding. Notwithstanding the evolution of a variety of tests for the assessment of visual function, ophthalmologists still rely primarily on distance and, to a lesser extent, near visual acuity to plan their patient management. It is important to identify those tests of visual function that correlate best with the patient's ability to function in the seeing world, and to develop appropriate QOL instruments for use in ophthalmic disorders.

Attitude of Health Personnel↗
PubMed1996

Teletherapy for subfoveal choroidal neovascularisation of age-related macular degeneration: results of follow up in a non-randomised study.

AIM: A preliminary report indicated stable or improved vision in 12 of 19 patients with subfoveal choroidal neovascularisation treated with 12 or 15 Gy of 6 MV photons to the affected macula after an average follow up of 18 months. Here the prolonged follow up findings in this group of treated patients is reported which was further increased to 41. METHODS: Forty one patients with subfoveal choroidal neovascularisation were treated with 10, 12, or 15 Gy of 6 MV photons to the macula of the affected eye. Thirteen eyes of 12 patients were also observed as a non-randomised comparison group. RESULTS: At 12, 18, and 24 months of follow up the mean change in visual acuity in eyes treated with radiotherapy was less than 1 Bailey-Lovie line from that measured at presentation. By contrast, the eyes in the comparison group lost 3.7 lines of acuity at 12 months which increased to 4.5 at 24 months. These differences were highly significant at each of the time points. When initial visual acuity was taken into account, treated eyes lost on average 12% of baseline acuity throughout follow up, whereas eyes belonging to the untreated group lost 50% of baseline acuity at 1 year, and 75% at 2 years. There was no significant difference in visual outcome between the three dose regimens used, which may simply be a reflection of the small sample size in each group. There was no evidence of radiation induced retinopathy or optic neuropathy in any treated patients. CONCLUSIONS: Teletherapy appeared to have a treatment effect in eyes with subfoveal choroidal neovascularisation resulting in maintained visual function without significant radiation induced morbidity.

Aged↗
PubMed1995

Conventional wisdom is a poor predictor of the relationship between discipline policy, student misbehaviour and teacher stress.

Will an effective discipline policy improve student misbehaviour and result in a reduction of teacher stress? It is commonly believed that student misbehaviour is a major cause of teacher stress, and that the degree of student misbehaviour is reflected in student suspension rates. Moreover, it is believed that student misbehaviour can be reduced by improving a school's discipline policy through the collaborative efforts of whole school communities. As a result of growing concern about student misbehaviour and teacher stress, a Whole School Approach to Discipline and Student Welfare programme was implemented throughout the Australian state of Victoria. This paper reports on the evaluation studies that were conducted to assess the effectiveness of the programme and examine the assumptions which underpinned its implementation. Data were obtained from 4,072 primary and secondary school teachers. Although longitudinal analyses suggested that the programme was effective in reducing teacher stress, there was no mean change in student misbehaviour. Structural equation analyses showed that there was little relationship between a school's discipline policy and the perceived level of student misbehaviour. It was also found that student suspension rates were not related to student misbehaviour, but could be predicted on the basis of a school's discipline policy and the self-esteem of teachers. Two and three wave causal analyses also demonstrated the problems associated with using cross-sectional research to support major policy decisions. Overall, these studies showed that there is little point in trying to reduce teacher stress by reducing student misbehaviour. Rather, it is more appropriate to develop a supportive organisational climate that enables teachers to cope with the student misbehaviour that confronts them.

Adolescent↗