Impression cytology in conjunctivitis.

A technique is described for studying the cellular response in various conjunctival disorders. A round plastic disc (Thermanox) is pressed against the patient's conjunctive, and the material adhering to the disc is stained with a modified Wright's stain (Diff-Quik) for light microscopy. This method compares favourably with the classic conjunctival scraping method. The advantages of the impression technique are that no local anesthetic is needed for abtaining conjunctival samples, it is painless and can readily be used in children, repeated samples can be taken within a short time, the staining procedure can be completed within 15 seconds, and the discs can be processed for electron microscopic studies of the cellular samples.