Cartography of impression cytology

Impression cytology is a minimally invasive diagnostic procedure allowing the collection of a monolayer of cells from the conjunctival surface. Both light and electron microscopy study of individual cellular changes, as well as the analysis of two-dimensional ocular surface changes, can be evaluated. Its most widespread application is for the detection and grading of squamous metaplasia. Grades for the morphological changes of squamous metaplasia have been described. We have developed a regional mapping technique that records the distribution of the various grades over the ocular surface areas sampled. This technique may offer greater sensitivity to variations in the distribution of squamous metaplasia in response to disease or therapy.