Long Term Follow-up Of Dry Eye And The High-order Aberrations After LASIK And Their Effects On Visual Quality

Objective:To observe dry eye and high-order aberrations(HOAs)before and after laser in-situ keratomileusis(LASIK)and to evaluate their effects on visual quality.Method:Totally 58 myopia patients(116 eyes)were enrolled from June 2008 to June 2010 in our hospital,who were interviewed before and on 1a,3a,5a after operation.Their total HOAs,third-order coma,third-order trefoil and fourth-order spherical aberration of the corneal surface 0s and 10 s after blinking were measured,and their uncorrected visual acuity(UCVA),spherical equivalent(SE),corneal fluorescent staining,Schirmer I test were taken.OSDI questionnaire was scored,dry eye was then diagnosed and graded.Result:The postoperative incidences of dry eye were higher than that before operation,and the ratio of moderate and severe dry eye,especially the latter,was gradually increased.UCVA increased and SE decreased after operation but did not change thereafter(P>0.05).OSDI scores were significantly higher than that before operation and increased with time(P<0.05).SIt decreased initially and restored by 5a after operation,meanwhile BUT remained significantly lower than the preopertive level(P<0.05).The HOAs obtained 10 s after blink were higher than 0s(P<0.01),and the augment of spherical aberration was the most significant.As to the same time point,the post-operative HOAs were higher than that before operation(P<0.01),and the elevation of spherical aberration was still the most significant.After operation,there was no difference among dry eye and non-dry eye patients on HOAs obtained 0s after blinking(P>0.05).There was no difference between mild dry eye and non-dry eye patients on HOAs obtained 10 s after blinking(P>0.05),however,the HOAs of moderate and severe dry eye patients were higher than non-dry eye patients(P<0.05),and the spherical aberrations increased most dramatically.5 years after surgery,the HOAs differences between two testing time points of dry eye patients had no correlation with UCVA(P>0.05),but positively correlated with OSDI scores(P<0.05).Conclusion:LASIK causes long-term and complex changes in the HOAs of the patient’s eye.The instability of tear film caused by dry eye increased patient’s HOAs and eventually impair the patient’s visual quality,which mainly attribute to the increase of spherical aberration.