The Changes Of Conjunctival Goblet Cells Density And MUC5AC In LASIK And The Relation Between Goblet Cells Density , MUC5AC And Tear Films

Objective To study the changes of conjunctival goblet cells density(GCD) and the content of mucin MUC5AC after suction ring application in LASIK and the relation between the changes of goblet cells density , MUC5AC and tear films'stability. To investigate the possible pathogenesy of dry eye after LASIK and to provide methods for preventing and treating dry eye after LASIK.Methods Conjunctival impression cytology was used to collect samples on 60 eyes that underwent LASIK for the correction of myopia. Four pairs of samples were taken on each eye at different times. The first pair was taken preoperatively before application of the suction ring. The second,third and fourth pair were taken from the same sites at 1 week,1 month and 3 month after surgery consecutively.The samples were stained with Periodic Acid Schiff's (PAS) and GCD was measured.Suction time(ST), breakup time of tear films (BUT),schirmer values and corneal fluorescein staining (FLU),the content fo total protein in tear films and OD of MUC5AC were observed preoperatively,1 week,1 month,3 month postoperatively.Correlations were used to determine the significance of relation between the postoperative GCD and ST, BUT,schirmer values and FLU. Correlations were used to determine the significance of relation between the postoperative OD and GCD,BUT ,schirmer values and FLU. Results ST was 10~26s.Compared with peroperative one,postoperative GCD, BUT,shirmer values,FLU,OD showed a statistically significant decrease respectively (P<0.01). Compared with peroperative one , postoperative content of total protein in tear films showed no statistically significant.There was a negative correlation between ST and GCD at 1 week and 1 month after surgery.There was a positive correlation between BUT and GCD postoperatively. Schirmer values were positively correlated with GCD at 1 week and 1 month after surgery. FLU was negatively correlated with GCD at 1 week and 1 month postoperatively. Schirmer values and FLU had no correlation with GCD at 3 month postoperatively. GCD and BUT were positively correlated with OD at 1 week,1 month and 3 month postoperatively. Schirmer values were positively correlated with OD at 1 week postoperatively.There was no correlation between Schirmer values and OD at 1 month and 3 month postoperatively. There was no correlation between FLU and OD at 1 week,1 month and 3 month postoperatively.Conclusion The stability of tear films was decreased after LASIK.Impression cytology showed reduction in goblet cell density where the suction ring exerted pressure on the conjunctiva, probably because of the length of the suction time. The OD of MUC5AC was decreased afer LASIK.And the loss of goblet cells and MUC5AC may contribute to the changes in tear films'stability. .