The use of impression cytology in ocular surface diseases

Impression cytology (IC), using cellulose acetate filter papers is a simple, noninvasive technique that aids in the diagnosis of several disorders of the ocular surface.These disorders include ocular surface squamous neoplasia, dry eye syndrome, limbal stem-cell deficiency, specific viral infections, vitamin A deficiency, allergic disorders, conjunctival melanosis, and malignant melanoma. IC has been used increasingly to assist in diagnosis of ocular surface disease, improve our understanding of the pathophysiology of ocular surface disease, and provide biomarkers to be used as outcome measures in clinical trials.