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. 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. Substantial efforts are currently underway to control the disease in Latin America and equatorial Africa, now that an effective, nontoxic medication, ivermectin, is available. Optometrists are helping to solve the logistic challenges for treatment of this disease, as most onchocerciasis endemic areas are remote with difficult access.
