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Biomedical subjects

A P Rotchford

Publications and source records attributed to A P Rotchford.

8 recordsLinked to original sources
PubMed2006

Epithelial proliferative potential of organ cultured corneoscleral rims; implications for allo-limbal transplantation and eye banking.

AIMS: To determine the epithelial proliferative capacity of organ cultured limbal tissue and correlate this with various donor and eye banking factors. METHODS: 24 corneoscleral limbal (CSL) rims left over from penetrating keratoplasty were split in half and set up as in vitro explant cultures. Corneal epithelial proliferative potential (CEPP) was assessed by the number of "cycles" of growth achieved before explants underwent exhaustion and failure to generate an epithelium to subconfluence. The dependence of CEPP on the age of the donor, time of death to enucleation, time of enucleation to organ culture, and time in organ culture in the eye bank was determined. RESULTS: CSL rims were capable of up to four cycles of culture with a wide variation between tissue samples. Of the various factors examined, death to enucleation time was the only statistically significant factor affecting the CEPP (regression coefficient: -0.062 (cycles/hour), CI -0.119 to -0.004, p = 0.037). Time in organ culture had little effect on CEPP. CONCLUSIONS: Preselected organ cultured CSL rims from eye banks may offer a viable alternative tissue source for use in allo-limbal transplantation.

Adult↗
PubMed2004

The effect of corneal thickness on intraocular pressure measurement in patients with corneal pathology.

BACKGROUND/AIM: To compare intraocular pressure (IOP) measurements taken by the Goldmann applanation tonometer, the Tono-Pen and the ocular blood flow pneumotonometer in eyes with varying central corneal thickness (CCT) due to penetrating keratoplasty (PK), keratoconus (KC), and Fuchs' endothelial dystrophy (FED). METHODS: IOP was measured with the Goldmann applanation tonometer, Tono-Pen XL, and OBF pneumotonometer in 127 eyes with the following corneal abnormalities. There were 56 eyes that had undergone PK, 37 eyes with KC, and 34 eyes with FED. CCT was measured using an ultrasound pachymeter after IOP determinations had been made. RESULTS: Mean IOP measurements in all three patient groups were significantly higher when measured by OBF pneumotonometer. Linear regression analysis showed that patients with FED had a significant increase in IOP with increasing CCT of 0.18 mm Hg/10 microm using the Goldmann tonometer, 0.15 mm Hg/10 microm with the Tono-Pen, and 0.26 mm Hg/10 microm with the OBF pneumotonometer. In patients with KC and after PK, linear regression analysis did not show a significant effect of CCT on IOP. A multivariate linear regression model controlling for age, sex, graft size, and patient group, showed that the effect of CCT on IOP for Tono-Pen (0.13 mm Hg/10 microm CCT) and Goldmann (0.14 mm Hg/10 microm CCT) were significantly lower than for the OBF pneumotonometer (0.26 mm Hg/10 microm CCT). CONCLUSIONS: This study found that mean IOP measurements using the OBF pneumotonometer were significantly higher than those made using the Goldmann applanation tonometer or Tono-Pen in eyes with a variety of cornel pathologies. The OBF pneumotonometer was found to be most affected by variation in CCT. For all three instruments, the relation between IOP and CCT depended on the corneal pathology and was greatest for FED.

Aged↗
PubMed2002

Reasons for poor cataract surgery uptake - a qualitative study in rural South Africa.

OBJECTIVES: To understand the reasons for poor cataract surgery uptake in people with blindness or severe visual impairment in rural South Africa. METHODS: A qualitative analysis of detailed, domiciliary interviews with a community-based random sample of elderly Zulus who were blind or severely visually impaired as a result of operable cataract, who had previously been invited for surgery but had failed to attend. RESULTS: Fear of surgery and a fatalistic attitude to the inevitability and irreversibility of blindness in old age were the main reasons for failure to attend for surgery. There was a lower level of disability and perceived need than had been assumed for people with such poor visual acuity. Non-surgical western style health care for systemic illness was common but few patients had sought any form of assistance for their poor vision. Issues of cost and accessibility were relatively unimportant. CONCLUSION: Provision of affordable and accessible cataract surgery for the blind and severely visually impaired members of a community does not guarantee that it will be taken up. Other barriers to surgery may be revealed when practical issues such as cost and accessibility are addressed. Perceptions of visual disability among subjects with cataract may differ from simple objective clinical standards.

Aged↗
PubMed2002

Assessing diabetic control--reliability of methods available in resource poor settings.

AIMS AND METHODS: To examine the reliability of random venous or capillary blood glucose testing, random urine glucose testing, and a current symptom history in predicting a high HbA1c in Type 2 diabetic patients taking oral hypoglycaemic agents in a poorly controlled rural African population. RESULTS: For a cut-off point for HbA1c of > or = 8%, for random venous plasma glucose of > or = 14 mmol/L (present in 47.2% of subjects), specificity was 97.1% (95% CI 85.1-99.9), sensitivity 56.8% (48.8-64.5) and positive predictive value (PPV) 98.9% (94.2-99.9). HbA1c > or = 8% is predicted by a random capillary blood glucose of 17 mmol/L (present in 28.4% of subjects) with specificity 100% (90.0-100.0), PPV 100% (93.7-100.0) and sensitivity of 34.3% (27.2-42.1). HbA1c > or = 8% is predicted by the presence of heavy glycosuria (> or = 55 mmol/L) (present in 35.6%) with specificity 94.1% (80.3-99.3), sensitivity of 41.9% (34.1-49.9) and PPV 97.1% (89.9-99.6). Polyuria/nocturia (present in 31.3%) was the only symptom found to be associated with poor control, with a specificity for predicting HbA1c of > or = 8% of 81.5% (61.9-93.7), PPV 89.1% (76.4-96.4) and sensitivity 30.6% (22.9-39.1). CONCLUSIONS: Where resources are short, random glucose testing can be used to detect a significant proportion of those with the worst control with a high degree of specificity enabling primary care staff to modify treatment safely. Where facilities are limited capillary blood or urine testing with reagent strips, may be substituted for venous plasma testing in the laboratory. A symptom history was insufficient to replace biochemical testing, but where this is unavailable, urinary symptoms may be helpful.

Black People↗
PubMed2002

Diabetes in rural South Africa--an assessment of care and complications.

OBJECTIVES: To describe the diabetic population under care of the public health sector in a district in rural KwaZulu-Natal, to assess the nature of their care, their glycaemic control and the extent of their complications. SUBJECTS AND METHODS: Two hundred and fifty-three diabetic patients consecutively attending clinics for review were interviewed and examined, and where available a 12-month retrospective review of clinical records was performed. Random blood glucose, haemoglobin A1c (HbA1c) and urine albumin/creatinine ratio were assayed. RESULTS: Acceptable glycaemic control (HbA1c < 2% above normal population range) was found in only 15.7% of subjects (95% confidence interval (CI): 11.4-20.8%). Mean HbA1c was 11.3%. The prevalence of hypertension (blood pressure > or = 160/95 mmHg and/or prescribed antihypertensive medication) was 65.4% (CI: 59.0-71.1%). Of 129 patients who were prescribed antihypertensives, 14.0% (CI: 8.5-21.2%) were normotensive (< 140/90 mmHg). Severe obesity was present in 36.5% (CI: 30.4-42.9%). Rates of attendance for review and compliance with diabetic medications were high. Blood glucose monitoring was not regularly performed and medications were rarely modified. Complications were common and mostly undiagnosed. Retinopathy of any grade was found in 40.3% of patients (CI: 33.2-50.9%) and was severe enough to warrant laser photocoagulation in 11.1% (CI: 8.5-21.2%). Microalbuminuria was found in 46.4% (CI: 40.0-53.0%) and foot abnormalities attributable to diabetes in 6.0% (CI: 3.4-9.7%). CONCLUSIONS: Care and control of diabetes in this rural community is suboptimal. There is a need for primary care staff to focus on modifying prescriptions in the face of poor blood glucose control and/or uncontrolled hypertension. Additional training and support for nursing staff and education for patients will be central to achieving this level of intervention.

Age Distribution↗
PubMed2000

Rapid assessment of cataract surgical coverage in rural Zululand.

OBJECTIVE: Cataract surgical coverage (CSC) is a useful indicator of the degree of success of a cataract intervention programme. However, because previously described methods are time-consuming and labour-intensive, they are rarely performed. This study describes a simple and inexpensive assessment of CSC based on screening of pensioners at pension delivery sites in a rural district. DESIGN: Random cluster-based cross-sectional survey. SETTING: State pension distribution sites in Hlabisa, a rural district in KwaZulu-Natal, South Africa. SUBJECTS: 562 old-age pensioners. METHOD: Subjects found to be blind (visual acuity < 3/60) and those reporting a history of eye surgery were examined using a torch and direct ophthalmoscope by an ophthalmologist. OUTCOME MEASURES: Cases of blindness due to operable cataract and post-cataract surgical subjects were identified. RESULTS: CSC was found to be 38.5% (95% confidence interval 29.1-47.9%). Blindness prevalence was 10.3%, with 69.0% due to cataract.

Aged↗
PubMed1998

Compliance with timolol treatment in glaucoma.

PURPOSE: To assess levels of compliance in elderly patients on timolol eyedrops for glaucoma. METHODS: A postal questionnaire was sent from the general practitioner to 86 patients over 55 years of age on repeat prescriptions for timolol eyedrops. The questionnaire asked details about the duration of treatment, family history, the level of understanding of the disease and the importance of treatment, other regular medication, side-effects attributed to the drops and how often patients omitted their drops. A search of practice and local hospital dispensing data was carried out to assess how frequently monthly repeat prescriptions for timolol eyedrops were dispensed over a 12 month period. This allowed a total volume to be calculated for each patient. RESULTS: Twenty-four per cent of patients admitted to omitting eyedrops either occasionally or frequently. Fifty-one per cent were found to have had insufficient drops dispensed to comply with treatment as prescribed. In non-complaint patients the mean period without drops was 85 days of the year, with a maximum of 165 days. CONCLUSION: Compliance with treatment is poor and patients underestimate their level of defaulting when questioned.

Aged↗