Impression Cytology On The Ocular Surface After Laser Excimer Surgery

ObjectivesWe apply with the technique of impression cytology to observe the change of ocular surface after laser in situ keratomileusis and laser assisted sub-epithelial keratectomy. We analyses the pathological change of conjunctiva, the squamous metaplasia of conjunctiva, to compare and reveal the relationship of tear secretion, tear film stability, and the staging of squamous metaplasia.To learn to the pathological change of ocular surface after corneal surgery. To evaluate the usefulness of impression cytology in analyzing of ocular surface after excimer.MethodsIn this randomized study, 40 eyes of 20 patients underwent LASIK and 40 eyes of 20 patients underwent LASEK to correct myopia during March to November in 2005 in Changzheng Hospital were selected. Tear secretion, tear film stability and impression cytology were examined preoperatively and 1, 3and 6 months postoperation. Accoding to the technique of Nelson's methods, we collected conjunctival cells from nasal bulbar conjunctiva with cellulose filters. We used PAS to stain goblet cells and their secretions and hematoxylin as counterstain to stain epithelial cells. We collected the different stage of squamous metaplasia during the different stage before and after surgery. Data were entered in an Excel (Microsoft) spreadsheet and analyzed with SPSS 11.0. The Wilcoxon signed rank test was used to compare preoperative and postoperative values of all measurements. The relationship among tear film break-up time, tear secretion and the stage of squamous metaplasia of conjunctiva were evaluated by Spearman rank correlation analysis. Results are presented as mean values ±standard error of the mean. Probalility (P) values less than 0.05 were considered significant.Results1 . The mean stage of squamous metaplasia value of LASIK patients was 0.20...