Experimental siderosis of the cornea--an electron microscopic study
Tanaka, M.
Nippon Ganka Gakkai Zasshi 84(9): 1262-1271
1980
ISSN/ISBN: 0029-0203 PMID: 7223559 Document Number: 162660
Whether the corneal stroma has a channel to transport substances and migrating cells, and whether the keratocyte has a phagocytic activity were investigated. Intrastromal channels and phagocytic activity of the keratocytes were demonstrated by causing corneal siderosis in rabbits under 2 conditions. An injected Hb solution dispersed into the corneal stroma forming a round electron-dense body and was seen in the space between collagen lamellae and keratocytes. At 24 h after the injection the cell membrane of the keratocytes contacting the Hb particles started to invaginate their cell bodies and surrounded them. Three days after the injection, keratocytes started to contain large phagosomes. The number of lysosomes was small in the cytoplasm and the number of wandering cells was as low as under the normal conditions even 60 days after the injection. The formation of gap junctions between the keratocytes associated with Hb particles was frequently observed. The Hb solution injected into the anterior chamber was seen in the corneal stroma during increased intraocular pressure. In these cases endothelium of the cornea disappeared and was replaced with several layers of fibroblasts just underneath the Descemet's membrane. Hb particles were also seen in the Descemet's membrane. In the stroma there were many wandering cells with phagosomes. Numerous Hb particles occurred in the space between the collagen lamellae without being phagocytozed by keratocytes and wandering cells. Hb particles changed their shape, size and electron density toward the anterior stroma. The structure of the particles in the anterior stroma was similar to calcium phosphate.