HISTOPATHOLOGY OF THE OCULAR SURFACE AFTER EYE RUBBING

Purpose. This study demonstrates the effects of eye rubbing on ocular surface tissue. Methods, Rabbits (3-4 kg; n = 24) were killed at 0, 4- h, 8-h, and 12-h intervals after a 5-min period of eye rubbing. Ocular surface tissues were studied by light and scanning electron microscop y. Contralateral eyes served as controls. Eye rubbing was accomplished by using digital pressure over the closed eyelid with a force suffici ent to appreciate by palpation the orbital rim. Biomicroscopic examina tion revealed marked vascular injection of the conjunctiva. Ocular sur face tissues studied included the lid margins, the upper and lower tar sal conjunctivae, the bulbar conjunctiva, and the cornea. Results, Cha nges in the ocular surface included dramatic alteration in the upper t arsal conjunctiva when compared with controls. The cornea and bulbar a nd lower tarsal conjunctiva were not altered when compared with contro l tissues, except for some increase in exfoliating cells in the cornea . The surface epithelial cells of the upper tarsal conjunctiva had a s pheroidal structure and were markedly elevated, the microprojections w ere altered, and there was evidence of increased cellular exfoliation. These changes were most pronounced at the 0 and 4-h time points, less noticeable at 8 h, and no appreciable changes were observed when comp ared with control tissues at 12 h. Conclusion, This study demonstrates that eye rubbing causes surface alterations in the stratified cuboida l to columnar epithelial surface of the upper tarsal conjunctiva while sparing the stratified squamous epithelial surface of the distal lid margins and cornea.