Onchocerciasis and other eye problems in developing countries: a challenge for optometrists.

BACKGROUND: Onchocerciasis, also known as River Blindness, affects about 18 million people around the world, resulting in severe visual impairment or blindness for approximately 2 million. METHODS: The disease is transmitted through the bite of a tiny black fly, which breeds in fast moving rivers and streams. The fly injects immature forms of the parasite worm, Onchocerca volvulus, whose microfilariae migrate to superficial tissues, and may invade any part of the eye. In the eye, living microfilariae may be found in any ocular structure, however, sclerosing keratitis, a severe corneal involvement is the major cause of blindness from the disease. RESULTS: Substantial efforts are currently underway to control the disease in Latin America and equatorial Africa, now that an effective, nontoxic medication, ivermectin, is available. CONCLUSIONS: Optometrists are helping to solve the logistic challenges for treatment of this disease, as most onchocerciasis endemic areas are remote with difficult access.

PIP: Onchocerciasis is commonly known as River Blindness and affects about 18 million people around the world. It is transmitted by black flies that breed in river and stream rapids and transmit the parasitic microfilariae, Onchocerca volvulus, to people who live and work near such rivers. Infection with the microfilariae results in blindness or visual impairment for 1 or 2 million people. The microfilariae migrate to superficial tissues and may invade any part of the eye and ocular structure. Living worms cause little damage, however, their death triggers a localized inflammation which can lead to blindness. Sclerosing keratitis, a severe corneal involvement, is the major cause of blindness from the disease. The World Health Organization (WHO) Expert Committee on Onchocerciasis has estimated that 9% of the disease is found in Africa, the rest occur in Yemen and Latin America. Treatment with ivermectin is contraindicated for pregnant and lactating women, children under 5 years of age, asthmatics, and people with other diseases. The WHO Onchocerciasis Control Program in 11 countries of West Africa has eliminated the risk of onchocerciasis by aerial spraying of black fly breeding sites only from 1 country. A single annual oral dose (150 mg/kg) of ivermectin can reverse early lesions in the cornea. Ivermectin must be taken annually to sustain protection against blindness, thus its incorporation into primary health care along with malaria, AIDS, trachoma, xerophthalmia, and cataract is most cost effective. Nigeria and Tanzania have optometry schools, and optometrists can play a significant role in onchocerciasis control and blindness prevention programs by training local health care workers to distribute invermectin in vision screening programs.

Testing the FOCOMETER--A new refractometer.

The FOCOMETER, an optometer which measures spherical refractive errors, is intended to provide rural or economically disadvantaged populations spherical prescriptions without the need for complicated protocols, expensive equipment, or electricity. FOCOMETER readings were compared with the spherical equivalent determined from autorefraction and subjective trial lens refractions in children, and with retinoscopy in adults. Over the range of refractive errors tested (-4 to +5 D) reasonably close readings, within one-half a diopter, were found for comparisons with autorefraction and retinoscopy and about one-tenth of a diopter difference was found between subjective refractions and the FOCOMETER.

"Mradi Wa Afya Mashuleni:" the Tanzania School Health Program.

PIP: The Tanzania School Health Program has been functioning for about 1 year; its main objective is to make use of the educational system to promote health and resolve problems associated with poor environment or lack of knowledge about health. Another objective is to use the capability of lay medical care to remedy minor illnesses. The principal goals are: 1) to improve the health of primary school children through first aid, health education, preventive care, safe water, sanitation, and improved school farms; 2) to extend these benefits to the schools' villages by community participation; 3) to test and measure strategies in pilot programs in Dodoma and Singida Regions in order to recommend a plan for national expansion. Tables give statistics for: 1) proportion of schools with water supply; 2) proportion with latrines; 3) health and medical problems; 4) proportion of schools with a shamba (farm); and 5) average distance of primary school to the nearest main road, dispensary, and hospital. Further plans to assess improvement in health status will be possible when a more intensive medical survey has been completed.^ieng