Experimental ocular onchocerciasis in cynomolgus monkeys. II. Chorioretinitis elicited by intravitreal Onchocerca lienalis microfilariae

Richard David Semba, J. J. Donnelly, J. H. Rockey, J. B. Lok, A. A. Sakla, H. R. Taylor

Research output: Contribution to journalArticle


Chorioretinitis due to onchocerciasis is a major cause of blindness, and the pathogenesis is poorly understood. We have developed an experimental model for onchocercal chorioretinitis using cynomolgus monkeys (Macaca fascicularis). Two normal monkeys and two monkeys which had received prior sensitization with subcutaneous injections of live Onchocerca lienalis microfilariae were given intravitreal injections of either 0, 10, 50 or 500 live microfilariae. Posterior segment changes included disc edema, venous engorgement, retinal vasculitis, intraretinal hemorrhage, and progressive retinal pigment epithelial (RPE) disturbances. Histopathological findings included perivascular infiltrates with eosinophils, eosinophilic choroiditis, and RPE hypertrophy, hyperplasia and loss of pigment. Microfilariae in the retina had no surrounding inflammation but were found adjacent to areas of RPE alterations. Overall the inflammatory reaction in the two unsensitized monkeys was more severe than that seen in the sensitized monkeys. The retinal appearance of the monkeys resembled that found in human onchocerciasis, and this model appears to be a promising one for future investigations.

Original languageEnglish (US)
Pages (from-to)1642-1651
Number of pages10
JournalInvestigative Ophthalmology and Visual Science
Issue number11
Publication statusPublished - 1988


ASJC Scopus subject areas

  • Ophthalmology

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