Ocular leprosy in nine-banded armadillos following intrastromal inoculation.

Leprosy shows a higher percentage of ocular involvement than any other systemic infection. In humans, the cornea is the first ocular tissue affected. Our previous studies in armadillos with naturally acquired and experimental disseminated leprosy showed that 44% had corneal infection. Mycobacterium leprae is found in armadillo burrows in Louisiana, U.S.A., and ocular abrasions may be the portal of entry for these organisms in wild armadillos. To test the cornea as a route of infection, we injected eight armadillos intrastromally with 2 x 10(6) M. leprae in 1 microliters. Two and 4 months later, the armadillos were sacrificed and their eyes processed for light- and electron-microscopy. After 2 months, M. leprae were found in histiocytes mainly in the corneal limbus, sclera and bulbar conjunctiva. At 4 months, however, there was a visible corneal leproma in one animal. Microscopically, it was found to be a histiocytic granuloma with heavy M. leprae invasion. In addition, cells were seen in the anterior chamber. Leprosy is endemic in regions where other corneal infections which compromise the epithelial barrier property are prevalent and where leprosy bacilli are found in the environment. The entry of leprosy bacilli into the cornea may produce lesions which spread posteriorly in the eye.

Histopathological changes in the eyes of mangabey monkeys with lepromatous leprosy.

Leprosy is the third leading cause of preventable blindness; however, little is known about the spread of infection to the eye. We have studied the eyes of three sooty managabey monkeys. Two were experimentally infected with Mycobacterium leprae; the third was not infected. In one of the infected animals there was histopathological evidence of lepromatous leprosy as evidenced by a chronic inflammatory infiltrate at the limbus, and detection of acid-fast bacilli in the corneal stroma, blood vessel walls, and corneal nerves. The latter were damaged as a result of the bacillary invasion. Electron microscopy revealed involvement and distortion of keratocytes with M. leprae and invasion of the corneal stroma by macrophages containing bacilli. Both infected animals showed focal collections of lymphocytes in the superficial stroma of the conjunctiva and in the ciliary body. This is the first report of the ocular manifestations of leprosy in any primate, including man, in which the duration of infection is known.

Blood staining of the cornea in Hansen's disease. A light- and electron-microscopic study.

Blood staining of the cornea was studied by light and electron microscopy: a 55-year-old male with Hansen's disease had blood staining of the cornea due to intracorneal hemorrhage; he received a partial-thickness keratoplasty following 1 year after the onset of the staining. The excised specimens revealed deposits of degraded erythrocytes in the stroma. Numerous dense granules, probably of erythrocytic breakdown products, were phagocytosed by macrophages as well as parenchymal cells. The presence of macrophages was limited to the middle part of the stroma in which newly formed vessels were remarkable.

Blood staining of the cornea in Hansens disease

Blood staining of the cornea was studied by light and electron microscopy: a 55-year-old male with Hansen's disease had blood staining of the cornea due to intracorneal hemorrhage; he received a partial-thickness keratoplasty following 1 year after the onset of the staining. The excised specimens revealed deposits of degraded erythrocytes in the stroma. Numerous dense granules, probably of erythrocytic breakdown products, were phagocytosed by macrophages as well as parenchymal cells. The presence of macrophages was limited to the middle part of the stroma in which newly formed vessels were remarkable.