Oncocercosis

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British Journal of Ophthalmology 1995; 79: 157-162

157

Onchocerciasis in Ecuador: ocular findings in Onchocercavolvulus infected individuals
P J Cooper, R Proaflo, C Beltran, M Anselmi, R H Guderian

Abstract Little is known of the epidemiology and clinical picture of ocular onchocerciasis in South America. Asurvey of onchocercal eye disease was performed in the hyperendemic area of a rain forest focus of onchocerciasis in Esmeraldas Province in Ecuador. A total of 785 skin snip positive individuals fromblack and Chachi Amerindian communities were examined. The blindness rate attributable to onchocerciasis was 0.4%, and 8.2% were visually impaired. Onchocercal ocular lesions were seen in a highproportion of the study group: 33.6% had punctate keratitis, microfilariae in the anterior chamber and cornea were seen in 2890/o and 33.5% respectively, iridocyclitis was seen in 1.5%, optic atrophy in5.1%, and chorioretinopathy in 28.0%. Sclerosing keratitis was not seen. The prevalence of all ocular lesions increased with age. Punctate keratitis was strongly associated with microfilarial counts inthe cornea and chorioretinopathy was correlated with infection intensities in the cornea and anterior chamber. Chachi Amerindians had higher anterior chamber microfilarial counts and a greaterprevalence of punctate keratitis than blacks though blacks had a greater prevalence of iridocyclitis and optic nerve disease. The pattern of ocular disease resembled rain forest onchocerciasis in west Africawith few severe ocular lesions in the anterior segment and all blinding lesions attributable to posterior segment disease.
(BrJ Ophthalmol 1995; 79: 157-162)

which is largely absent from the rainforest.7 In the Americas, foci of disease have been described in Mexico, Guatemala, Colombia, Venezuela, Brazil, and Ecuador. Earlier reports from Guatemala58 and Venezuela9 indicated ocular...