Impression cytological study for ocular surface disorders of late stage eye burns.

OBJECTIVE This study aims to explore the ocular surface of late stage eye burns by impression cytology (IC) and analyze the cytological changes and their relationship to ocular surface abnormalities. PATIENTS AND METHODS 68 eyes with late stage eye burns (thermal burn: 28 eyes; alkali burn: 26 eyes; acid burn: 14 eyes), procured from 68 patients (aged ranges from 17 to 70 years old). Ocular surface abnormalities were assessed under slit lamp and graded. These were broadly classified as eyelid, corneal, conjunctival, and tear film abnormalities. Impression cytological examination was taken by cellulose acetate filter paper for all eyes. Samples were analyzed and scored under light microscope, including the status of epithelial cells, goblet cells, mucus and inflammatory cells. All the results and data were compared and analyzed by SPSS software (version 16.0). RESULTS According to the IC results, loosed cell-to-cell density and nuclear abnormality, keratinization, reduced goblet cell amount, disorder of mucus, and existing of inflammatory cells were observed in almost all the cases. The IC results were significantly correlated to the ocular surface injury severity (r=0.458, p<0.01). The ocular surface injury severity mostly contains three aspects: the corneal neovascularization scales, the present or absent of recurrent epithelial erosion and the tear film break-up time. Eyes with the foreword three symptoms were inclined to have higher IC scores. The epithelial cell-to-cell density, goblet cell and mucus amount were all correlated to tear film break-up time. However, inflammatory cell density showed no significant correlation to the conjunctival hyperemia grade. But inflammatory cell density correlated to the corneal opacity grade and epithelial stability status. CONCLUSIONS IC examinations could reflect the cytological disorders and relative injury severity of the ocular surface in late stage eye burns. It provides further information which will be useful in surgery and therapy.