PLEOMORPHISM OF STROMAL EOSINOPHILS IN MURINE EXPERIMENTAL ONCHOCERCAL KERATITIS

Onchocercal keratitis (river blindness) is one of the leading worldwid e causes of blindness. Light microscopic analysis of human specimens a nd corneal tissue from experimental models has implicated the eosinoph il as an important cell in the inflammatory response, Our previous stu dies in experimental murine onchocercal keratitis have demonstrated th at the inflammatory infiltrate is composed primarily of eosinophils di splaying ring shaped or bilobed nuclei. However, a number of cells wer e not characterizable by light microscopy, presumably due to mechanica l distortion. To more fully characterize the inflammatory cell infiltr ate, we examined corneal specimens by transmission electron microscopy . In addition to typical eosinophils with bilobed and ring shaped nucl ei, this approach revealed cells with variable nuclear morphology and cell shape which contained the dense cored granules characteristic of eosinophils, Hence, the degree of pleomorphism of eosinophils is broad er than appreciated and underscores the importance of this cell in exp erimental murine onchocercal keratitis.