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Biomedical subjects

T R Carmichael

Publications and source records attributed to T R Carmichael.

15 recordsLinked to original sources
PubMed2005

Effective and accurate screening for diabetic retinopathy using a 60 degree mydriatic fundus camera.

UNLABELLED: OBJECTIVES. To establish whether an experienced endocrinologist could screen accurately for diabetic retinopathy using mydriatic 60 degree fundus photographs compared with a reference standard, viz. the combined highest scores of two experienced ophthalmologists. DESIGN: Retrospective review of 60 degree colour transparency photographs taken over a 6-year period. Retinopathy was graded in a standardised way. SETTING: Patients attending the diabetic clinic at Johannesburg Hospital, South Africa. SUBJECTS: Fifteen hundred and seventeen patients (2446 eyes) formed the basis for the study. Patients were included if there was more than 50% readability of the fundus photographs. OUTCOME MEASURES: Outcome measures were prevalence of any retinopathy and presence of referable (severe) retinopathy. Interobserver agreement was measured using the kappa statistic, and sensitivity and specificity of the screener were evaluated. RESULTS: The prevalence of retinopathy at the clinic was approximately 30%, but only about 12% was severe enough to warrant referral to the ophthalmology outpatient department. The endocrinologist was very accurate in determining cases requiring referral; there was 97% agreement with the reference standard, viz. the combined highest score of two experienced ophthalmologists (gold standard). Correlation on the determination of any retinopathy was less accurate (80% agreement), mostly owing to the endocrinologist reporting more isolated microaneurysms than the ophthalmologists. The screening method used gave a sensitivity of 83% and specificity of 99% which are within recommended standards. CONCLUSIONS: The screening strategy using a mydriatic fundus camera at the diabetic clinic was found to be effective and accurate and greatly reduced the number of possible referrals to the ophthalmology outpatient department.

Adult↗
PubMed2001

Clinical evaluation of twice-daily emedastine 0.05% eye drops (Emadine eye drops) versus levocabastine 0.05% eye drops in patients with allergic conjunctivitis.

PURPOSE: The efficacy and safety of emedastine 0.05% eye drops (Emadine; Alcon Laboratories, Inc, Fort Worth, Texas), a new H(1) antagonist, were studied in comparison to levocabastine 0.05% eye drops (Livostin; Janssen-Cilag N V, Berchem, Belgium) during a twice-daily treatment schedule for 6 weeks in adult and pediatric patients with seasonal allergic conjunctivitis. METHODS: In a prospective, multicenter, randomized, double-masked, parallel group study, 222 patients with allergic conjunctivitis were randomized (221 received treatment) to either emedastine or levocabastine, instilled twice daily for 6 weeks. Patient diaries were completed four times daily (before the morning and evening instillations, at noon, and in the afternoon), and clinical examinations were conducted at regular intervals. Primary efficacy variables of ocular redness and itching and secondary efficacy variables of chemosis, eyelid swelling, patient diary data, and physician's global assessment were analyzed. RESULTS: Both emedastine and levocabastine produced a statistically significant (P =.0001) reduction in itching and redness within 5 minutes of the first instillation. All signs and symptoms improved progressively over the 6-week treatment period. After 7 days of use, and throughout the remainder of the study, emedastine was statistically superior to levocabastine (P <.006) in preventing and alleviating the signs and symptoms (itching, redness, chemosis, and eyelid swelling) of allergic conjunctivitis. CONCLUSIONS: Emedastine 0.05% eye drops administered twice daily are more efficacious than levocabastine 0.05% eye drops in the prevention and treatment of the signs and symptoms of allergic conjunctivitis in adults and children of 4 years and above. Both emedastine 0.05% eye drops and levocabastine 0.05% eye drops were well tolerated.

Adolescent↗
PubMed1990

Topical steroids in the treatment of central and paracentral corneal ulcers.

During an 18-month period a prospective randomised trial was conducted on 40 selected patients with bacterial corneal ulcers. Two groups were compared: one was treated with antibiotic only and the other with antibiotic plus steroid. Complications were similar in the two groups. No delay in healing rate of the ulcers was seen with the use of topical steroid. Two methods of assessing visual improvement are discussed, but it was not possible to demonstrate a difference in visual outcome between the two groups.

Administration, Topical↗
PubMed1987

Factors predisposing to central corneal ulceration in a developing population.

Over a 1-year period all patients presenting to St John's Eye Hospital with corneal ulceration were studied. The local and general factors predisposing to central (primarily infective) corneal ulceration are discussed. Episodes of corneal trauma and climatic droplet keratopathy were the major local factors and these occurred against the background of a generally poor nutritional status.

Adult↗
PubMed1987

Use of contrast sensitivity measurement in the detection of subclinical ethambutol toxic optic neuropathy.

Contrast sensitivity was measured by means of Arden grating plates in 100 patients on medication for pulmonary tuberculosis. The scores were abnormal in 38.2% of the patients whose therapy included ethambutol for three months, and 36.7% of the patients on similar treatment for six months. In comparison with age matched groups of patients on a regimen where streptomycin replaced ethambutol a statistically significant number of the patients on ethambutol had abnormal scores. This study suggests that Arden contrast sensitivity plates would be effective in detecting subclinical toxic optic neuropathy due to ethambutol and therefore could be used for routine monitoring of ocular function of patients on ethambutol. Loss of contrast sensitivity may explain why some patients on ethambutol with normal visual acuity and colour perception may still complain of visual disturbance.

Adult↗
PubMed1985

Corneal ulceration at an urban African hospital.

During a one-year survey 283 corneal ulcers from 274 patients were seen at St John's Eye Unit of Baragwanath Hospital. Central bacterial ulcers constituted the largest problem, and the commonest isolate in this group was Streptococcus pneumoniae. Mycotic and dendritic keratitis were relatively uncommon, while marginal catarrhal ulceration secondary to chronic staphylococcal lid disease was frequently seen. The microbiology of the various ulcers is described, and the placing of organisms into classes is stressed in determining significance of isolates. Many of the patients were male Africans who were either manual labourers or unemployed. Half the patients had used topical antibiotics before presentation.

Adult↗
PubMed1985

Plasma exchange in the treatment of Mooren's ulcer.

We report a case of early progressive Mooren's ulcer in which plasma exchange was attempted as a means of modifying the immune response. This therapy alone was not successful, but might be successfully combined with cytostatics and conjunctivectomy.

Adult↗
PubMed1982

Measles notifications -- the first year.

Measles is a major cause of childhood mortality in the developing world. Observed trends in the USA confirm the efficacy of a measles control programme. South Africa launched such a programme in 1975 with the introduction of free vaccine for all children. In order to enhance and monitor this campaign, measles became a notifiable condition on 24 August 1979. Notifications received in the first year are reviewed and the observed patterns are discussed.

Adolescent↗
PubMed1982

Blinding trachoma--a public health challenge.

Trachoma constitutes a public health problem in several areas of the RSA. The epidemiology of trachoma is examined. The notifications of trachoma for the past decade are presented and the value of notification of this disease is discussed. Control of blindness due to trachoma may be achieved by involving the community in which it occurs.

Adolescent↗
PubMed1981

The spread of cholera in South Africa.

The current cholera epidemic in the RSA began in October 1980 and is part of the seventh pandemic. Initial investigation of the epidemic revealed a virtually closed system of water supply, which explained the distribution of the early cases. The spread of cholera in the RSA is examined and local factors contributing to cholera transmission are discussed. Attempts are being made to prevent cholera from becoming endemic in the RSA and long-term improvements in health facilities in the susceptible areas of the country are being undertaken.

Adult↗