Ocular malaria.
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Eye Infections, Parasitic↗
Biomedical subjects
S Lewallen
Publications and source records attributed to S Lewallen.
Prevention of blindness in leprosy: an overview of the relevant clinical and programme-planning issues.
Visual disability continues to be a significant problem in leprosy patients due to cataract, chronic iridocyclitis, and corneal disease. Clinical and epidemiological aspects of these problems are described and the current status of eye care in leprosy programmes is discussed.
Blindness↗
Excess mortality associated with blindness in leprosy patients in Korea.
Vision loss and blindness are potential complications of leprosy. There is little data available to indicate the impact of eye complications on life expectancy and quality of life. We sought to determine the relative risk of death in blind leprosy patients compared to nonblind leprosy patients. A population-based ocular survey of 510 mycobacteriologically negative leprosy patients in rural South Korea, conducted in 1988, formed the study population. After a 7-year period patients were traced to determine their status (alive, dead, lost to follow up). Blind patients showed a 4.8-fold risk of death, even after adjusting for other factors, compared to nonblind patients. Young blind leprosy patients had the highest relative risk of death. Excess mortality was not associated with any specific cause of blindness, ocular pathology, or type of disease. Findings from our study suggest that all leprosy patients with ocular disabilities (including those released from antileprosy treatment) should be targeted to receive eye care to prevent vision loss. Particular emphasis should be placed on young patients.
Aged↗
Aggressive conjunctival squamous cell carcinoma in three young Africans.
Polymerase chain reaction was used to test for the presence of human papillomavirus in conjunctival squamous cell carcinomas from three young Africans with aggressive disease. Two of these patients had the acquired immunodeficiency syndrome. Test results for human papillomavirus were negative [corrected] in all three cases.
Acquired Immunodeficiency Syndrome↗
Carcinoma of the conjunctiva and HIV infection in Uganda and Malawi.
AIM: To investigate the association of human immunodeficiency virus (HIV) infection and carcinoma of the conjunctiva in Africa, and the role of human papilloma virus type 16 (HPV-16). METHODS: Patients in Uganda and Malawi presenting to eye clinics with lesions suspicious of carcinoma were studied. Pathological confirmation of eye lesions was sought. HIV testing of patients who were biopsied and, in Uganda, of matched case control subjects was carried out as was testing of a sample of fixed biopsies for HPV-16 by polymerase chain reaction (PCR). The HIV-1 serology, histopathology of conjunctival biopsies (conjunctival intraepithelial neoplasia (CIN), invasive carcinoma, other lesions), and prevalence of HPV-16 infection were determined. RESULTS: Of Ugandan patients, 27/38 (71%) with carcinoma (27 invasive carcinoma, 11, CIN) were HIV positive compared with 12/76 (16%) of controls (odds ratio 13, 95% confidence interval 5-38). The calculated population aetiological fraction of carcinoma associated with HIV was 66%. Of 32 Malawian patients (20 invasive carcinoma, 12 CIN), 25/29 tested (86%) were HIV positive. HPV-16 infection was found in 7/20 (35%) of carcinoma samples, 0/9 pingueculae, and 2/6 conjunctivitis samples. CONCLUSIONS: HIV infection is strongly associated with an apparent increase in the incidence of conjunctival carcinoma in Africa. While ultraviolet light is probably the prime risk factor and HPV-16 is implicated in a proportion of cases, the interactions of ultraviolet light, HIV, HPVs, and other factors are unclear in the pathogenesis of carcinoma. The disease represents another model of multifactorial epithelial carcinogenesis.
AIDS-Related Opportunistic Infections↗
Changing patterns of corneal disease and associated vision loss at a rural African hospital following a training programme for traditional healers.
AIMS/BACKGROUND: Use of African traditional eye medicines (TEM) is associated with the presence of corneal disease, delay in presentation, and vision loss. An interactive training programme was conducted with traditional healers in Chikwawa District, Malawi and changes in the pattern of corneal disease assessed in patients presenting to the district hospital after the training. METHODS: All patients presenting to the district hospital with corneal disease for a 15 month period before intervention and a 12 month period after intervention were enrolled in the study. Interviews and examinations were carried out by the same person using a standardised, pretested form. RESULTS: Among the 175 pre-intervention and 97 post-intervention patients, delay in presentation improved only slightly. Blindness among patients reporting the use of TEM decreased from 44% to 21%; bilateral corneal disease in patients using TEM decreased from 31% to 10%. Multivariate analysis demonstrates that poor vision in corneal disease patients continues to be associated with TEM use and distance from the district hospital. CONCLUSION: As there were no other relevant eye health programmes in the district it is believed that this collaborative eye care programme with the traditional healers was likely to have been responsible for many of the changes in the pattern of corneal disease in the district. Although the changing patterns are encouraging and are likely to improve with additional collaboration, distance to a district hospital will continue to be a barrier to timely use of Western eye care services.
Blindness↗
Role for traditional healers in eye care.
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Eye Diseases↗
Corneal decompensation after cataract surgery. An outbreak investigation in Asia.
PURPOSE: During 5 days in January 1994, two visiting expatriate ophthalmologists performed extracapsular cataract surgery on 111 patients at a nonprofit hospital in Asia. The authors investigated the development of postoperative corneal edema. METHODS: An epidemiologic and clinical investigation was undertaken by a review of clinical charts, interview of personnel involved, an examination and interview of patients who underwent surgery, and a laboratory simulation of the disinfection procedure used. RESULTS: Follow-up was available on 58% of the patients. The attack rate was at least 37% and likely to be approximately 64%. The attack rate was highest the first 2 days of surgery. Multivariate analysis showed that the day of surgery was the only characteristic significantly associated with the presence of corneal edema. A simulation of the disinfection technique used (soaked in 2% glutaraldehyde and rinsing) showed that significant levels of glutaraldehyde remain in instruments with small lumens after the rinse. CONCLUSION: The epidemiologic data and simulation information are compatible; the lack of adequate rinsing of small lumen instruments soaked in glutaraldehyde is the most probable cause of this incident. Recommendations for surgeons on surgical expeditions are proposed.
Asia↗
Peripheral corneal ulcers associated with use of African traditional eye medicines.
The most common cause of monocular blindness in Africa is corneal opacification. Traditional eye medicines (TEM) are widely used in Africa and their use has been associated with corneal ulceration, however, no controlled studies of the effects of TEM on the cornea have been published. We conducted a case-control study of 39 patients with corneal ulcers matched to controls with severe conjunctivitis. Microbiological investigations were conducted on 20 cases. There was a significant association between corneal ulceration and TEM use and, in particular, peripheral corneal ulcerations were significantly associated with TEM use.
Adolescent↗
Traditional healers in primary eye care.
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Corneal Diseases↗
A population-based survey of the prevalence of refractive error in Malawi.
Refractive errors, particularly myopia, are a common problem in industrialized countries, but the impression exists that myopia may be relatively uncommon in non-industrialized societies. We conducted a population-based survey of refractive error in two groups of Malawians: a group of rural agricultural workers (n = 510) and a group of students at an urban teachers' college (n = 534). The overall prevalence of myopia was low; 2.5% (95% confidence interval 1.3%, 3.7%) of participants had an error of -0.5 D or greater. The mean refractive error (right eye) in the urban student group was +0.52 D compared to +0.62 D among the rural agricultural workers and the excess myopia was accounted for by significant myopia (> or = -0.75 D) in a few individuals, rather than an overall shift towards myopia within the urban student group. Among the rural agricultural workers, literacy predicted refractive error (right eye), with a mean of +0.59 D in the rural literate compared to +0.67 D in the rural illiterate. These findings support the notion that myopia is uncommon in non-industrialized societies and that it is associated with increased literacy but we have not identified specific risk factors within this group to predict the occurrence of significant myopia. In settings such as Malawi, refractive services should be targeted to urban centers, where more educated populations are likely to be found.
Adolescent↗
Lagophthalmos in a multibacillary population under multidrug therapy in the People's Republic of China.
Lagophthalmos may be the most common potentially blinding ocular condition in leprosy. The magnitude of the problem among multibacillary patients has not been determined. We sought to ascertain the magnitude of lagophthalmos in a multibacillary leprosy patient population under multidrug therapy (MDT) (both newly diagnosed and with a prior history of dapsone monotherapy) in China and assess factors associated with its presence. In a survey of 640 multibacillary patients 3.8% of the newly diagnosed patients and 10.2% of the patients with prior dapsone monotherapy had lagophthalmos. Corneal disease and vision loss were common in both groups. Poor compliance with MDT, duration between onset and diagnosis, and duration on dapsone monotherapy were associated with the presence of lagophthalmos. Our findings suggest that there may be a threshold at which MDT must be maintained to prevent lagophthalmos. Early leprosy diagnosis and treatment would also lessen the incidence of lagophthalmos in these patients. The high proportion of lagophthalmos patients with corneal disease suggests that there has been inadequate eye care for these patients.
Adult↗
Current concepts in the surgical management of lagophthalmos in leprosy.
Existing data suggest that, at a minimum, 2% of paucibacillary patients and 5% of multibacillary patients have lagophthalmos; at least 290,000 people worldwide have leprosy-related lagophthalmos. Surgical intervention is the only method for correcting lagophthalmos; effectiveness of the different procedures commonly used has not been measured. Results from a survey of eye care providers revealed that surgeons in Asia used a wide range of different techniques for the correction of lagophthalmos while almost all of the surgeons in Africa used tarsorrhaphy. There is a need to evaluate surgical outcome of these techniques and to develop guidelines to assist in increasing the number of surgeries for lagophthalmos in leprosy patients.
Corneal Diseases↗
Barriers to acceptance of cataract surgery among patients presenting to district hospitals in rural Malawi.
The objective of this research was to assess the barriers to cataract surgical acceptance by blind rural Malawians recognized and referred for surgical correction at district hospitals. Cataract blind recognized and referred for surgery by the ophthalmic assistants in Chikwawa and Nsanje Districts were interviewed 9-12 months after enrolment to determine if they had undergone cataract surgery and to assess factors associated with surgical acceptance. There were significant gender-specific baseline differences between men and women presenting to the ophthalmic assistants. Patients living near the district hospital were also most likely to present to the ophthalmic assistant. Men with lower socioeconomic status were more likely to accept surgery than men with higher socioeconomic status. Men and women who either talked to someone about cataract surgery or knew another aphakic patients were more likely to accept surgery. The best approaches to improving cataract acceptance given existing resources might be to encourage patients undergoing cataract surgery to educate and motivate others to accept surgery and to train existing village level health staff in cataract recognition and referral. Economic barriers and lack of family support are likely to continue to impede improved cataract surgical acceptance, especially among women.
Cataract Extraction↗
Herpes zoster ophthalmicus in Malawi.
OBJECTIVE: The objective was to describe the complications and outcomes of herpes zoster ophthalmicus in a population of young Africans with a high seroprevalence of human immunodeficiency virus type 1 in which treatment often is delayed and in which antiviral drugs are not available. METHODS: Twenty-seven patients with herpes zoster ophthalmicus presenting consecutively to a large urban hospital were examined and followed. Treatment was limited to that which was locally available. RESULTS: Visual outcomes were poor. Sixty-six percent of eyes had final visual acuity less than 20/60. Forty percent had light perception or no light perception visual acuity. Severe keratouveitis and corneal perforation were common and responsible for most poor visual outcomes. CONCLUSION: Young Africans with herpes zoster ophthalmicus are at a high risk for significant visual loss.
Adolescent↗
Multidrug therapy and eye disease in leprosy: a cross-sectional study in the People's Republic of China.
BACKGROUND: Factors associated with leprosy-related eye disease in a multidrug therapy (MDT) treated population in China were assessed to determine if status prior to inclusion in the MDT programme (newly diagnosed leprosy patient or leprosy patient on prior dapsone monotherapy) contributed to the prevalence of ocular pathology. METHODS: Trained leprosy paramedical workers in Sichuan Province examined 974 leprosy patients in a standardized fashion. Univariate analyses and multiple logistic regression were used to assess the contribution of demographic and clinical parameters to leprosy-related eye disease. RESULTS: In both groups (prior dapsone and new MDT) leprosy-related eye disease was associated with a longer distance to leprosy health worker or health centre. Among patients with a history of prior dapsone monotherapy, age and duration on dapsone monotherapy were also associated with leprosy-related ocular morbidity. Among newly diagnosed leprosy patients the prevalence of ocular morbidity remained between 8% and 11% regardless of when the patient started MDT. CONCLUSIONS: Our findings suggest that, even when case detection is good, ocular pathology will still occur in MDT treated leprosy patients. There remains an important role for health workers in the prevention of ocular morbidity. Our data also demonstrated that pooling of results from all patients (newly diagnosed and on prior dapsone monotherapy) in a leprosy control programme will likely give rise to inadequate estimates of risk of ocular disease due to variable clinical disease histories in these groups.
Adult↗
Retinal findings in Malawian patients with AIDS.
The purpose of this study was to determine the prevalence of retinal disease in a group of patients with AIDS in Malawi. Indirect ophthalmoscopy was performed on 99 patients with AIDS who were admitted consecutively to a medical ward at a central hospital. Necrotising retinitis was present in one eye of one patient examined. Non-infectious retinopathy was present in 13%. Retinitis is less common in AIDS patients from Africa compared with those from developed countries; it is believed that most patients die before acquiring it. Non-infectious retinopathy may also be less common.
AIDS-Related Opportunistic Infections↗
Traditional eye medicine use among patients with corneal disease in rural Malawi.
Over a 15 month period all patients with corneal ulcers presenting at two district hospitals were interviewed regarding demographic and clinical characteristics and their use of traditional eye medicines (TEM). Of the 583 patients interviewed, 33.8% reported using TEM. There were no age or sex differences in TEM use. Patients who reported TEM use took, on average, 51 days between onset of symptoms and presentation while patients who denied TEM use took 13 days. Sixteen per cent of TEM users had a vision in the affected eye of < 3/60 on presentation compared with 5% of non-TEM users. The frequent use of TEM and the presence of numerous traditional healers in rural areas of Africa suggest that eye care programmes could benefit greatly by including traditional healers in primary eye care activities.
Adolescent↗