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Biomedical subjects

D Kent

Publications and source records attributed to D Kent.

At least 19 recordsLinked to original sources
PubMed2000

The influence of retinopathy of prematurity on ocular growth.

PURPOSE: Retinopathy of prematurity (ROP) stage 3 eyes that require treatment have a greater tendency to myopia compared with eyes with mild ROP. As the mechanisms controlling this myopia are as yet ill understood, we undertook this study to investigate what effect the initial stage of ROP and modality of treatment had on ocular growth. METHODS: Eighty-five children were assessed. All children were refracted and underwent 'through-the-lid' biometry using the Zeiss Humphrey biometer 820. The printout obtained was then recorded on video so that the scan could be captured on computer for formal calibration and measurement by a masked observer. Differences in the distribution of variables between the stages of ROP were analysed by one-way analysis of variance, non-parametric Kruskal-Wallis one-way analysis of variance or Mann-Whitney U-test as appropriate. RESULTS: A difference between the stages of ROP was apparent only for posterior segment length (PSL) (R: p = 0.03; L: p = 0.05) and a borderline difference for anterior chamber depth (ACD) (R: p = 0.06; L: p = 0.06). However, if stage 3 was divided into categories of treated and untreated, axial length (AL) achieved borderline significance (R: p = 0.07; L: p = 0.05) but with no difference between laser-treated and the other stages for AL. Lens thickness (LT) also appears to be influenced by type of treatment (R: p = 0.06; L: p = 0.13). Myopia was associated with stage 3 (R + L: p = 0.0001) and if stage 3 was subdivided the significance was maintained only for the laser- and cryotherapy-treated eyes. CONCLUSIONS: Laser-treated eyes were less myopic than those treated with cryotherapy. AL does not explain all the myopia found in stage 3 treated eyes. The study confirms the tendency towards anterior segment arrest in stage 3 ROP.

Biometry↗
PubMed1999

Modulation of retinal pigment epithelial cell behavior by Agaricus bisporus lectin.

PURPOSE: To determine whether Agaricus bisporus lectin (ABL) binds retinal pigment epithelial cells (RPEs), to conduct a preliminary viability study of RPEs exposed to ABL, and to evaluate the effects of ABL on RPE proliferation and RPE-mediated matrix contraction in vitro. METHODS: Using cultured bovine RPEs, immunohistochemistry was used to study ABL binding. Morphologic and trypan blue exclusion techniques were used for toxicity studies. The effect of ABL on RPE proliferation was investigated by [methyl-3H]-thymidine incorporation. The effect of ABL on RPE-mediated matrix contraction was evaluated with RPE-populated three-dimensional collagen matrices. RESULTS: ABL bound to RPE cells. This binding was inhibited by asialomucin. No change in RPE morphology or trypan blue exclusion compared with controls was observed in RPEs incubated with 5 to 60 microg/ml ABL for 3 days. Twenty-four-hour incubations of RPEs with ABL significantly inhibited RPE proliferation in a dose-dependent way, 40 microg/ml ABL inhibited proliferation by 83% (SE 14, P<0.05). ABL showed a dose-dependent significant inhibition of RPE-mediated collagen matrix contraction over 3 days, with 93% inhibition compared with controls by 40 microg/ml lectin (P<0.05). The inhibitory effect of ABL on proliferation and gel contraction was partly reversible after eliminating ABL from the culture medium. CONCLUSIONS: Bovine RPE cells bind ABL, and preliminary evaluations suggest that levels of ABL that are nontoxic to the cells potently inhibit RPE proliferation and RPE-mediated matrix contraction. ABL deserves further investigation as a potential inhibitor of RPE proliferation and cell-mediated matrix contraction in anomalous reparative processes such as proliferative vitreoretinopathy and as a laboratory tool for RPE behavioral studies.

Animals↗
PubMed1998

Recent immigration and the misery of motherhood: a discussion of pertinent issues.

In this paper it is assumed that the high rates of misery experienced by most new mothers in contemporary Western society are socially and culturally induced. Women from non-English-speaking backgrounds (NESB) recuperate from the stress of birth, often further complicated by morbidity from intervention, frequently alone and without practical household help. They often embark on their new mothering role with little support or guidance. In a Western society which markets a romanticized Anglo image of motherhood, where happy, contented, smiling babies and glamorous mothers appear as the norm, it is not surprising that women from NESB find becoming a mother in Australia difficult. Their difficulties are exacerbated as they frequently come from cultures where women are nurtured, valued and supported at this time in their lives. These women are often socially isolated in their new country, within an alien health system and separated from their normal birth and postpartum practices. Their misery can only be imagined, as mostly it is hidden and suffered alone. Providing a diagnosis of depression in women who are unhappy, but not clinically depressed, is likely to be even less helpful and more damaging for NESB women than for Anglo-Australian women. A diagnosis of depression excuses Western society for accepting responsibility for alleviating the isolation of new mothers by labelling them as 'sick'.

Attitude to Health↗
PubMed1998

Management of Irish patients with intraocular melanoma referred to Liverpool, England.

PURPOSE: This study reviews the results of patients referred from Ireland for treatment of an intraocular melanoma at the Ocular Oncology Service at St Paul's Eye Unit, Liverpool. PATIENTS AND METHODS: There were 57 patients with a median age of 55 years. Management included plaque radiotherapy (14), proton beam radiotherapy (17), local resection (10), endoresection (6), and enucleation (10). Fifty-two tumours involved the choroid. The tumours had a mean diameter of 11.4 mm and a mean thickness of 5.2 mm. RESULTS: The follow-up period had a median of 267 days. Retention of the eye was achieved in all 47 cases who underwent conservative management. Ninety percent of patients retained a vision of counting fingers, with an acuity of 6/12 or better in 50%. CONCLUSION: This group of patients gives an indication of the results that can be expected when uveal melanoma is managed by a variety of conservative techniques in a specialised ocular oncology service.

Brachytherapy↗
PubMed1998

Acute intraoperative suprachoroidal haemorrhage in ocular surgery.

PURPOSE/BACKGROUND: Acute intraoperative suprachoroidal haemorrhage (AISH) is the most sight-threatening complication of ocular surgery. We investigated the visual outcomes following this intraoperative event, patient characteristics that may predispose to it and the clinical features that may be of prognostic significance. METHODS: The records of 45 cases of AISH collected from ophthalmic centres in the United Kingdom, Republic of Ireland and Switzerland were reviewed. Two satisfactory controls in terms of operative procedure, surgeon, age (+/- 5 years) and gender were found for each of 33 of our cases. Systemic and ocular characteristics were compared for cases and controls, and the visual results of all cases of AISH are analysed. RESULTS: Cases and controls differed only in terms of axial length and pre-operative intraocular pressure, both of which were significantly greater for eyes that experienced an AISH (p < 0.05). Ten eyes (22.2%) achieved a final Snellen acuity of 6/12 or better. Statistically significant associations with a final acuity of counting fingers or worse included spontaneous nuclear expression (p = 0.02), retinal detachment (p < 0.0001), four-quadrant suprachoroidal haemorrhage (p = 0.007) and vision of perception of light or worse at the first dressing (p = 0.0001). Four of the 6 eyes that experienced an AISH during phacoemulsification surgery had a visual outcome of 6/12 or better, and this was significantly greater than for cases involving extracapsular cataract surgery (p = 0.004). CONCLUSION: The results indicate that longer axial length and higher pre-operative intraocular pressure are associated with increased risk of AISH. Poor visual results are more likely following spontaneous nuclear expression, retinal detachment, four-quadrant suprachoroidal haemorrhage or vision of perception of light or worse at the first dressing. The results also suggest that AISH complicating a phacoemulsification procedure has a more favourable visual prognosis than AISH that occurs during extracapsular cataract surgery.

Acute Disease↗
PubMed1998

Preventing disability and managing chronic illness in frail older adults: a randomized trial of a community-based partnership with primary care.

BACKGROUND: Effective new strategies that complement primary care are needed to reduce disability risks and improve self-management of chronic illness in frail older people living in the community. OBJECTIVE: To evaluate the impact of a 1-year, senior center-based chronic illness self-management and disability prevention program on health, functioning, and healthcare utilization in frail older adults. DESIGN: A randomized controlled trial. SETTING: A large senior center located in a northeast Seattle suburb. The trial was conducted in collaboration with primary care providers of two large managed care organizations. PARTICIPANTS: A total of 201 chronically ill older adults seniors aged 70 and older recruited through medical practices. INTERVENTION: A targeted, multi-component disability prevention and disease self-management program led by a geriatric nurse practitioner (GNP). MEASUREMENTS: Self-reported Physical function, physical performance tests, health care utilization, and health behaviors. RESULTS: Each of 101 intervention participants met with the GNP from 1 to 8 times (median = 3) during the study year. The intervention group showed less decline in function, as measured by disability days and lower scores on the Health Assessment Questionnaire. Other measures of function, including the SF-36 and a battery of physical performance tests, did not change with the intervention. The number of hospitalized participants increased by 69% among the controls and decreased by 38% in the intervention group (P = .083). The total number of inpatient hospital days during the study year was significantly less in the intervention group compared with controls (total days = 33 vs 116, P = .049). The intervention led to significantly higher levels of physical activity and senior center participation and significant reductions in the use of psychoactive medications. CONCLUSIONS: This project provides evidence that a community-based collaboration with primary care providers can improve function and reduce inpatient utilization in chronically ill older adults. Linking organized medical care with complementary community-based interventions may be a promising direction for research and practice.

Activities of Daily Living↗
PubMed1997

Pulsatile ocular blood flow in eyes with untreated choroidal melanoma.

PURPOSE: To investigate the effect of choroidal melanoma on pulsatile ocular blood flow (POBF). METHODS: Seventeen patients (10 men and 7 women) with unilateral untreated choroidal melanoma and 22 controls matched for age and sex were studied. Intraocular pressure (IOP), pulse amplitude (PA) and POBF were measured using the OBF Tonograph. In each patient, mean inter-ocular differences were analysed using the paired t-test. The correlation coefficient between tumour thickness and POBF was calculated. To assess the variation of this parameter, the coefficient of variation for three repeated readings was determined for healthy and affected eyes. RESULTS: In the control group, there was no significant difference between eyes in any parameter. In patients with melanoma, there was no significant difference in IOP and PA between affected and unaffected eyes. Mean POBF was significantly higher in affected eyes (1040 microliters min-1) than unaffected eyes (876 microliters min-1) (p = 0.003). There was no correlation between tumour thickness and absolute POBF (r = -0.24) or between tumour thickness and inter-ocular difference in POBF between affected and unaffected eyes (r = -0.17). Mean coefficient of variation of three repeated readings of POBF was 7.76% in healthy eyes and 8.97% in affected eyes. CONCLUSIONS: These findings suggest a high tumour blood flow or a global increase in choroidal blood flow in the presence of melanoma. POBF measurement may be useful in the clinical assessment of eyes with choroidal melanoma.

Aged↗
PubMed1994

Screening for ophthalmic manifestations of sickle cell disease in the United Kingdom.

There are marked variations in the manifestations of sickle disease in different populations. The ocular complications of this condition amongst the Afro-Caribbeans living in the United Kingdom have not previously been reported. We present the preliminary results of an ophthalmic screening programme at King's College Hospital, London. One hundred eyes of 50 patients with sickle cell disease were assessed. Full ocular examination was performed including fundus fluorescein angiography. We have looked at the haematological and clinical profile of the patients involved as well as the number of days spent in hospital during the year preceding the eye examination. The incidence of grade II retinopathy was found to be significantly higher than grade I in SC disease. This concurs with the results of the Jamaican screening and confirms that these patients are at higher risk of visual impairment than those with SS disease. Our results also agree with the Jamaican experience which suggest that visual morbidity is mostly due to complications of proliferative sickle retinopathy (PSR). However, the findings in patients without proliferative changes are different; in particular, angioid streaks leading to disciforms are an important cause of visual loss in Jamaica, but were not seen in any of the 98 eyes examined in this study. No correlation was found between the grade of retinopathy and age, sex, systemic complications and various haematological parameters except for the percentage of haemoglobin F, which was significantly higher in patients with grade I (7.6) compared with grade II (4.2) retinopathy (p = 0.0127).

Adolescent↗
PubMed1993

Risk factors for complications of chronic anticoagulation. A multicenter study. Warfarin Optimized Outpatient Follow-up Study Group.

OBJECTIVE: To define risk factors for complications that occur during warfarin therapy. DESIGN: Retrospective cohort study. SETTING: Five anticoagulation clinics. PATIENTS: Nine hundred twenty-eight consecutive patients receiving 1103 courses of warfarin. MAIN OUTCOME MEASURES: Hemorrhagic and thromboembolic complications. RESULTS: In 1950 patient-years of follow-up, there were 1332 bleeding events (4 were classified as fatal, 31 as life-threatening, 226 as serious, and 1071 as minor). The cumulative incidence of fatal bleeding was 1% at 1 year and 2% at 3 years. The cumulative incidences of first episodes of life-threatening and serious bleeding at 1, 2, 4, and 8 years were 1%, 2%, 5%, and 9% and 12%, 20%, 28%, and 40%, respectively. Of 156 patients who had a serious or life-threatening hemorrhage, 32% suffered a recurrence, typically within 1 year. Independent predictors of a first episode of serious bleeding included a mean prothrombin time ratio (PTR) of 2.0 or more during the course of treatment (relative risk, 3.0; 95% CI, 1.9 to 4.7); recent initiation of warfarin therapy (relative risk during the first 3 months compared with the rest of the first year, the second year, and anytime thereafter, 1.9 [CI, 1.3 to 3.0], 3.0 [CI, 1.8 to 4.8], and 5.9 [CI, 3.8 to 9.3], respectively); variability of the PTR over time (relative risk for the highest compared with the lowest tertile, 1.6 [CI, 1.2 to 2.7]); and the presence of 3 or more comorbid conditions (RR, 1.4 [CI, 1.1 to 2.5]). Age, reason for anticoagulation, use of interfering drugs, and hypertension were not associated with risk for bleeding. The risk for a thromboembolic complication at a PTR of less than 1.3 was 3.6 (CI, 2.1 to 6.4) times higher than at a PTR of 1.3 to 1.5. CONCLUSIONS: The incidence of warfarin-associated bleeding may be reduced by attending to modifiable risk factors (that is, highly variable PTRs and values greater than 2.0), frequent monitoring early in treatment, and careful patient selection. Older age, in and of itself, is not a risk factor.

Adult↗