Purpose: The technique of impression cytology using cellulose acetate filter paper as a debriding agent was evaluated.
Methods: Lesions were assessed using a slit-lamp biomicroscope before and after the impressions were taken and appropriate antibiotic therapy was started. The filter paper impressions were stained with hematoxylin-eosin and examined by light microscopy. The 72 corneal ulcers and three cases of suture infiltration around exposed corneoscleral cataract-related sutures were effectively debrided. Five of the six foreign bodies and all of the filaments in the six filamentary keratitis cases were removed with minimal damage to the surrounding cornea.
Results: Results of microscopic examination showed that the cells that were transferred to the filter paper were primarily the affected cells. In corneal ulcers, the degenerated epithelial cells, inflammatory cells, and organisms were removed. The inflammatory cells superimposed on affected epithelial cells in suture infiltration and the filaments of filamentary keratitis were removed. In cases of superficial corneal foreign bodies, the foreign bodies overlying a sheet of degenerated epithelial cells were lifted up.
Conclusion: "Impression debridement" improves the quality and efficiency of debridement for most of these conditions, with much less risk to the surrounding tissue than the conventional techniques. Besides being an adjunct to therapy, it simultaneously provides replicas of the lesions that give accurate histologic details after microscopic evaluation.