The incidence of microfilariae in the eye and of ocular lesions in relation to the age and sex of persons living in communities where onchocerciasis is endemic

The prevalence of the ocular lesions of onchocerciasis, amongst persons resident in endemic villages in savannah and forest regions of West Africa, is recorded in age and sex groups. The findings demonstrate a relationship between invasion of the eye by microfilariae and the appearance of ocular lesions. Microfilariae are more commonly found in the eyes of males than in those of females, and ocular lesions show a similar preponderance in males. The findings show that the transient “fluffy” corneal opacities are a feature of the early stages of ocular invasion by microfilariae, but that few permanent ocular lesions develop at this stage: the latter tend to develop in greatest numbers at the age when microfilariae are most common in the eye.