The natural history of ocular onchocerciasis over a period of 14--15 years and the effect on this of a single course of suramin therapy.

In 1959 a population of 638 persons over the age of seven years, suffering from heavy endemic onchocerciasis in the Sudan-Savannah of West Africa was examined, and approximately half were allotted to a group for treatment with suramin (up to a total of 4-2 g for healthy adults). In 1973 and 1974 it was possible to re-examine 145 persons allotted to the treatment group and 118 persons allotted to the control group. Measurements were made of the incidence of new "eye lesions", the progress of pre-existing "eye-lesions" and the deterioration in visual acuity. These were greater in men than in women, and increased with age. They were also greater in persons who in 1959 had microfilariae in the anterior chamber, and particularly in those who had already developed "eye lesions". Severe reactions occurred in a significant proportion of patients who received suramin, and one died. However, these was less deterioration in the eyes of persons in the treated than in the control group.