Explain the Conjunctival impression Cytology (CIC)?

Conjunctival impression cytology (CIC) is a simple, rapid and inexpensive method which is suitable for a field survey. By touching with a filter paper the lower temporal portion of the conjunctiva for about 3-5 seconds the desquamated layers of cells are transferred to the filter paper. This strip is then stained and examined. CIC is a useful test for the assessment of subclinical VAD. It detects the progressive loss of goblet cells in tile conjunctiva and the appearance of enlarged, keratinized epithelial cells.

CIC provides an early measure of the histological changes in the eye i. e, changes in the conjunctional epithelium with eventual keratinization. These changes are used to differentiate between normal children and those with mild xerophthalmia. Diagnosis is based on the absence or rare, appearance of goblet cells or mucin spots in sufficient quantity. The CIC technique is modified by another method in which cells are immediately transferred to a glass slide. This method is called Conjunctival impression cytology with transfer.