PubMed Health⌕ Search

Biomedical subjects

Susan Lewallen

Publications and source records attributed to Susan Lewallen.

7 recordsLinked to original sources
PubMed2006

Surgery for trachomatous trichiasis: findings from a survey of trichiasis surgeons in Tanzania.

AIMS: To measure the productivity and factors associated with high productivity of trichiasis surgeons. METHODS: A standardised, pretested questionnaire was posted to all trichiasis surgeons trained in Tanzania at the address listed at the time of training, and then followed up by post and telephone with those who did not return the form. Questions asked related to place of work, number of surgeries carried out, supplies and equipment available, and outreach activities. A random selection of high-productivity and low-productivity surgeons was invited to a focus group meeting to discuss factors that affected productivity. RESULTS: 28 of the trained surgeons had died, retired or could not be located. Forms were retrieved from 95 others. Productivity (averaged over the past 4 years) was low overall, but highly variable. The mean number of surgeries per year was 22.3 (SD 48.1) and the median was 7. The most important factor associated with higher productivity was conducting outreach activities. Conducting outreach was associated with having a complete set of instruments and consumables and with being able to identify a supervisor. CONCLUSIONS: Redesigning the provision of trichiasis surgery (in particular, supervision, support and community programmes/outreach) is necessary to ensure that the investment from training is used adequately.

Adult↗
PubMed2006

Malarial retinopathy: a newly established diagnostic sign in severe malaria.

Severe malaria is commonly misdiagnosed in Africa, leading to a failure to treat other life-threatening illnesses. In malaria-endemic areas, parasitemia does not ensure a diagnosis of severe malaria because parasitemia can be incidental to other concurrent disease. The detection of malarial retinopathy is a candidate diagnostic test for cerebral malaria. Malarial retinopathy consists of a set of retinal abnormalities that is unique to severe malaria and common in children with cerebral malaria. Its presence and severity are related to risk of death and length of coma in survivors. A large, prospective autopsy study of children dying with cerebral malaria in Malawi found that malarial retinopathy was better than any other clinical or laboratory feature in distinguishing malarial from non-malarial coma. However, visualization has to date relied on specialist examination techniques. Further studies are planned to evaluate the usefulness of funduscopy by general clinicians in a variety of settings across Africa. Studies of the retina and retinal blood vessels provide an unparalleled opportunity to visualize an infected microvasculature and its effect on neural tissue in vivo. This report reviews current knowledge of malarial retinopathy, including its use as a diagnostic test in the comatose child, and its value as a tool for research into the pathophysiology of cerebral malaria.

Eye Infections, Parasitic↗
PubMed2004

Differentiating the pathologies of cerebral malaria by postmortem parasite counts.

To study the pathogenesis of fatal cerebral malaria, we conducted autopsies in 31 children with this clinical diagnosis. We found that 23% of the children had actually died from other causes. The remaining patients had parasites sequestered in cerebral capillaries, and 75% of those had additional intra- and perivascular pathology. Retinopathy was the only clinical sign distinguishing malarial from nonmalarial coma. These data have implications for treating malaria patients, designing clinical trials and assessing malaria-specific disease associations.

Animals↗
PubMed2004

Cataract surgical coverage and outcome of cataract surgery in a rural district in Malawi.

BACKGROUND: Cataract is the leading cause of blindness in Malawi. We sought to determine the cataract surgical coverage and the outcome of cataract surgery in a rural district in Malawi to assess past performance of cataract surgical services. METHODS: From July to October 1999 we conducted a multistage random cluster survey to include 1630 residents aged 50 years or more in Chikwawa District. Visual acuity, cause of vision loss, history of cataract surgery and cause of poor vision (if less than 6/60) were assessed. Cataract surgical coverage, sight restoration rate and outcome were calculated by person and eye and for men and women separately. RESULTS: We examined 1384 people (84.9% of target). Twenty-one people (12 men and 9 women) (30 eyes) had received cataract surgery. The cataract surgical coverage rate was 35.6% (44.4% for men and 28.1% for women [odds ratio 2.0, 95% confidence interval 0.6-7.0]) at a visual acuity level of 6/60, and 55.3% (60.0% for men and 50.0% for women [odds ratio 1.5, 95% confidence interval 0.3-6.7]) at a level of 3/60. Only one eye of one subject had received an intraocular lens. Presenting visual acuity was 6/18 or better in 7 eyes (23.3%), 6/24 to 6/60 in 7 eyes, and worse than 6/60 in 16 eyes (53.3%). Among the 16 eyes with visual acuity less than 6/60, the vision could be improved in 8 with provision of aphakic spectacles. INTERPRETATION: Cataract surgical coverage in this population is similar to that reported from other countries in Africa. As in other settings, cataract surgical coverage was lower in women than in men. Poor outcomes in this population are partly due to surgical complications and partly due to a lack of aphakic correction. Surgical promotion programs will need to focus on differentiating intraocular lens surgery from (previously practised) intracapsular cataract extraction surgery.

Blindness↗
PubMed2002

Gender and use of cataract surgical services in developing countries.

OBJECTIVE: To determine, from the existing literature, cataract surgical coverage rates by sex and the proportion of cataract blindness that could be eliminated if women and men had equal access to cataract surgical services. METHOD: Methodologically sound population-based cataract surveys from developing countries were identified through a literature search. Cataract surgical coverage rates were extracted from the surveys and rates for women were compared to those for men. Peto odds ratios were calculated for each survey and a meta-analysis of the surveys was performed. FINDINGS: From a literature review and meta-analysis of cataract surveys in developing countries, we found that the cataract surgical coverage rate was 1.2-1.7 times higher for males than for females. For females, the odds ratio of having surgery, compared to males, was 0.67 (95% confidence interval (CI): 0.60- 0.74). Despite their lower coverage rate, females accounted for approximately 63% of all cataract cases in the study populations, and if they received surgery at the same rates as males, the prevalence of cataract blindness would be reduced by a median of 12.5% (range 4-21%). CONCLUSION: Closing the gender gap could thus significantly decrease the prevalence of cataract blindness, and gender-sensitive intervention programmes are needed to improve cataract surgical coverage among females.

Cataract↗
PubMedDate not supplied

Routine bilamellar tarsal rotation surgery for trachomatous trichiasis: short-term outcome and factors associated with surgical failure.

PURPOSE: To determine risk factors for early failure of the bilamellar tarsal rotation procedure in trachomatous trichiasis. METHODS: This was a prospective study in which the bilamellar tarsal rotation procedure was performed on 638 eyelids in Menofiya governorate in Egypt over a 4-year period. An analysis was performed to determine the incidence of early surgical failure (defined as one or more lashes touching the eyeball) after 8 weeks and to determine the risk factors for these failures. RESULTS: Follow-up data were available on 599 eyes at 8 to 10 weeks after surgery. Considering all eyes, failure (one or more lashes touching the eyeball) was noted in 98 eyes (16.4%). Failure was associated with preoperative corneal staining (RR, 3.27; 95% CI, 2.34 to 4.57), preoperative corneal opacity (RR, 1.64; 95% CI, 1.15 to 2.34), the use of silk sutures (RR, 54.82; 95% CI, 7.72 to 389.4), and the use of 4 or more sutures (RR, 1.24; 95% CI, 1.04 to 1.48). CONCLUSIONS: The finding that specific sutures or needles was associated with early failure of the bilamellar tarsal plate rotation procedure for trachomatous trichiasis was unexpected and deserves further study.

Blepharoplasty↗