AIM: To observe the dry eye and high-order aberrations(HOAs)before and after laser in situ keratomileusis(LASIK)and to evaluate their effects on visual quality.

METHODS: Totally 58 myopia patients(116 eyes)were enrolled from June 2008 to June 2010, 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 10s after blinking were measured, and uncorrected visual acuity(UCVA), spherical equivalent(SE), corneal fluorescent staining, S I t were taken. OSDI questionnaire was scored, dry eye was diagnosed and graded.

RESULTS: Five years after LASIK, OSDI scores gradually increased from 10.003±1.462 to 20.252±2.540, BUT decreased from 8.402±2.640s to 6.897±3.408s and S I t decreased from preoperative level 14.382±6.241mm/5min, but recovered to preoperative level of 13.432±4.206mm/5min. The HOAs obtained 10s after blink were higher than 0s, 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, and the elevation of spherical aberration was still the most significant. 5a after operation, there was no difference between dry eye and non-dry eye patients on HOAs obtained 0s after blinking(all P>0.05). There was no significant difference between mild dry eye and preoperative HOAs 10s after blink 5a after operation(all P>0.05). However, the HOAs of moderate and severe dry eye patients were higher than non-dry eye patients(all P<0.05). 5a after surgery, the HOAs differences between two time points of dry eye patients had positively correlated with OSDI scores.

CONCLUSION: The instability of tear film caused by dry eye in patients long-term after LASIK increases patient's HOAs and ultimately impair patient's visual quality, which mainly owe to the significant increase of spherical aberration.