[Cytologic evaluation of dry eye by brushing procedure: value of slide preparation by ThinPrep technique]

Recent clinical trials have indicated that an automated smear apparatus (ThinPrep process) of sample preparation has great diagnostic sensitivity. In this study, conjunctival brush cytology prepared using the ThinPrep method was applied in ocular surface disorders especially for dry eye status. To assess its diagnostic value in cellular samples, 35 patients with keratoconjunctivitis sicca (KCS) and 12 normal volunteer patients were examined using this technique. Conjunctival cells from normal controls revealed fine chromatin and polyhedral cytoplasm without keratinized cytoplasm. However, cellular samples from KCS revealed increased keratinized cells with pyknotic nuclei. They also contained extremely elongated cells. In KCS patients, the mean numbers of keratinized cells were significantly higher (32.3 cells/300 cells) than those of the normal control group (0.2 cells/300 cells). In patients with KCS, inflammatory cell counts were also higher than those of normal controls. Conjunctival cytology by the ThinPrep method obviously deserves additional trials as an adjunct to cytological evaluation of dry eye status, especially for quantitative ocular evaluation of various ocular lesions.