Effect Of 0.1% And 0.3%SH On Tear Film And Visual Quality Post FS-LASIK

Objective To study the effect of 0.1%and 0.3%SH on the dry eye related subjective symptoms,clinical signs and visual quality over time after the instillation in the mild and severe dry eye patients post FS-LASIK with the application of Keratograph 5M?OCULUS,Germany?and Optical Quality Analysis System?OQAS?,Visiometrics,Spain?.Methods A prospective randomly-controlled study.Pre surgery normal patients were evaluated again at 1week post FS-LASIK.30mild and 30severe dry eye patients were enrolled from April 2016 to April 2017 in Tianjin Medical University Eye Hospital.0.1%and 0.3%SH were randomly given in each dry eye group.OSDI?VAS?TFBUT?TMHs?NIBUT-avg?Schirmmer I test?corneal staining?OQAS were repeated at 1week?pre and 15min?30min?60min?120min and 180min post instillation?,1month and 3months at follow-up examination.The visual quality related parameters were OSI?mean OSI from the tear film analysis and MTF cut off.Difference in each parameter between two concentration groups were analyzed with the Multiple factor analysis of variance for repeated measurements.Results 0.3%group is better than 0.1%in alleviating OSDI(F_group=10.913,P=0.003)and cornea staining at 3months?P=0.027?and reducing the score of dry eye sensation?blurred vision?photophobia?itchness(F_group=5.082,9.184,4.831,8.972,P=0.032,0.005,0.037,0.006)in the mild dry eye group and there is a significant difference between 0.1%and 0.3%on blurred vision of VAS in severe dry eye group(F_group=-1.596,P=0.122).SIt and TFBUT were significantly improved after instillation in mild and severe dry eye group?P<0.05?.No statistic difference was observed between the concentration of SH in increasing the TMHs and NIBUT-avg in both mild and severe dry eye group;in the mild dry eye group TMHs increased at the 30min and 120min post instillation?P=0.032;P=0.05?,and was significantly reduced at 180min compared to 30min and 120min?P=0.029;P=0.019?;in severe dry eye group TMHs increased significantly at 15min post instillation at 1week follow-up?P<0.001?,and then gradually reduced.NIBUT-avg in 0.1%SH increased after the instillation,no significant difference compared to preoperation was observed among the following 3hours?all at P>0.05?.In 0.3%SH group NIBUT-avg were increased at 15min,30min,and were significantly reduced at60min,120min and 180min post instillation?P=0.040;0.047;0.041?,lower than pre FS-LASIK at 1month and 3months?P=0.053;0.044?.There is no statistic difference between the concentration of SH in the optical related parameters in both the mild and severe dry eye group?P>0.05?,the optical related parameters were not significantly different over time in 0.1%SH group but significantly different over time in 0.3%SH group(OSI:F _time=2.897,P=0.017;MTF:F _time=2.043;P=0.043;total OSI means:F _time=2.749,P=0.006);OSI were significantly increased at different time points in mild dry eye group(F_time=3.748,P=0.004).Mean values of total OSI were significantly increased in the severe dry eye group post the instillation.?Ftime=2.667,P=0.008?.In 0.1%SH group the mean value of total OSI at 1week post surgery?1.26±0.71?was siginifcantly higher than that at pre FS-LASIK?0.90±0.38??P=0.046?,the mean values of total OSI at various timepoints among 3hours post instillation were not statistically different from that at pre FS-LASIK?all at P>0.05?,were 1.26±0.55 and 1.25±0.55 at 1month and 3month post operation,higher than pre FS-LASIK level?P=0.047;0.017?;In 0.3%SH group total OSI at 1week post surgery?1.25±0.66?was siginifcantly higher than that at pre FS-LASIK?1.16±0.91??P=0.06?,till 120min post instillation total OSI were all significantly higher than that at pre FS-LASIK?all P<0.05?,no statistical difference was observed at 180min post instillation,were 1.65±0.79 and 1.30±0.49 at 1month and 3month post operation?P=0.046;P=0.667?.No significant difference of the blink times during the 20s tear film analysis between the 2 concentration was observed.There is no significant change of the blink times over time in mild dry eye while in the severe dry eye group there is a statistically increase at 1month post FS-LASIK compared to pre surgery and 1week post FS-LASIK?P=0.047,P=0.029?.A significant positive correlation was found between the blink times and OSDI?1week:r=0.590,p=0.021?,TH?1week:r=0.572,p=0.026;?,a negative correlation between the blink and TFBUT?1month:r=-0.557,p=0.031?,NIBUT-avg?1month:r=-0.524,p=0.045?.Conclusion Dry eye related symptoms are worse,the tear film stability is reduced post FS-LASIK.0.3%SH is better than 0.1%in alleviating the subjective symptoms and cornea staining in the mild dry eye post FS-LASIK,while no significant difference with optical related parameters.The dynamic change in the tear film will have a great influence on the optical quality in the dry eye patients post FS-LASIK.During the 3 hours post the instillation of 0.3%SH,the total OSI means increased in the severe dry eye;the total OSI means recover to the presurgery level earlier than the0.1%SH in the severe dry eye group after 3-month 0.3%SH application.