[The ultrastructural changes in the corneal lens stroma of wound healing process following epikeratophakia in rabbits].

We investigated the ultrastructural change of corneal lens+ stroma histologically following epikeratophakia in rabbits. Epikeratophakia was performed on rabbit corneas using cryolathed corneal lens+. At days 10, 16, 45, 63 and 90 after the operation, pachymetry was performed, and corneas were excised and analyzed histologically using an electron microscope. At days 16 to 63, collagen fibril density (CFD) in corneal lens+ stroma decreased 57 to 63% of that in the control cornea, but returned to 78% at day 90. The results of pachymetry revealed that postoperative increase of corneal thickness was greater than the expected value at days 10 and 16. However, after that the corneal thickness decreased gradually and became thinner than the expected value after 45 days postoperatively. At days 45 to 90, many activated keratocytes with dilated and well developed rough endoplasmic reticulum, suggestive of active collagen production, were observed in corneal lens+ stroma. Furthermore, at day 90, keratocytes with extended pseudopoidia that suggested phagocytic activity were also observed, especially in the subepithelial zone. These findings indicated that collagen fibrils in the corneal lens+ stroma were damaged under the influence of the cryolathing process and partially exfoliated postoperatively, however, collagen-producing activity increased gradually and the reconstruction of corneal lens+ stroma continued through day 90 after the operation.