Establishment Of A Rat Dry Eye Model And Study Of Pathogenesis Of Dry Eye

Abstract Objective To establish a dry eye rat model and then study the pathogenesis of dry eye. Methods We chose adult healthy Wistar rats for the model, and exposed their cornea and conjunctiva for 1/2, 6, 12, 24 hours and one week separately by suturing their eyelids to the skin. Then observed the pathologic and ultrastructural changes of the corneal and conjunctival epithelium and the lacrimal glands, and studied the expression of bcl-2 and bax in these tissues by immunohistochemical staining. Results From the study we learned that in the dry eye rat model, (1)the epithelium of cornea was absent, keratinized and even formed ulceration, and neovascular and inflammatory cells were found in the severe dry eye rat models; (2)the epithelium of conjunctiva was absent, the goblet cells were hyperplastic and neovascular and inflammatory cells soakaged in the tissue; (3) the lacrimal glands were hyperplastic and hypersecreted and inflammatory cells soakaged in the severe dry eye models; (4) ultrastructurally, the microvilli of epithelial cells reduced and even disappeared; and apoptotic cells were found in corneal and conjunctival epithelium; endoplast hyperplasia and mitochondria swelling were observed in the lacrimal glands; (5) along with the prolonged-time of exposing, the expression of Bax in corneal and conjunctival epithelium increased while Bcl-2 reduced. Conclusions (1) we can make successful dry eye rat model by mechanically exposing their cornea and conjunctiva; (2) in the dry eye rat model, the cornea, conjunctiva and lacrimal glands took on lots of changes both structurally and functionally; (3)the changes above probably be relevant to apoptosis of the corneal and conjunctival epithelium.