Conjunctival Impression Cytology by Using a Thermosensitive Adhesive: Polymerized N-isopropyl Acrylamide

Purpose: We aimed to evaluate a new technique using a thermosensitive glue coating for impression cytology of the ocular Surface. Methods: We prepared plasma polymerized N-isopropyl acrylamide (pNIPAM)-coated parylene C (poly(monochloro-p-xylylene)) films to obtain cytological samples from the conjunctival surface. We compared this new technique with the conventional nitrocellulose paper method in regards to the quality of impression cytology and quantity of the cells in 30 postmenauposal women with dry eye complaints. Results: The cellular material was adequate for evaluation in 28 (93%) of 30 eyes in pNIPAM-coated parylene group and in 18 (60%) of 30 eyes in the nitrocellulose group (P = 0.0002). pNIPAM-coated parylene technique was superior to the nitrocellulose technique regarding the mean number of cells per microscopic field (P = 0.00003), integrity of the cells (P = 0.00001), and cellular preservation (P = 0.0002). Conclusion: The number of cells and the quality scores were significantly higher in the pNIPAM-coated impression cytology technique than the nitrocellulose method.