Abstract:Objective:To investigate the refraction accuracy of three different measurements and their influencing factors after excimer laser corneal refractive surgery. Methods: Seventy-eight cases(154 eyes) performed with Excimer laser corneal refractive surgery from optometry clinic, the Eye Ear Nose and Throat Hospital, FuDan University were selected randomly from Dec 2008 to Jan 2009. Sphere,cylinder and cylinder axial of all the patients were measured three months(mean 14.2 weeks)before and after surgery by auto-refractomer wavefront analyzer and phoropter inspection(without cycloplegic). Higher-order aberration, corneal curvature and corneal thickness of every patient were also measured at the same time before and after surgery. Results: The cylinder of auto-refractor and phoropter were significantly different respectively(P < 0.05). Sphere, cylinder and cylinder axial of auto-refratomer and phoropter were significantly different (all P < 0.01) respectively. Sphere of wavefront analyzer and phoropter were statistician different (P < 0.01).The differences of sphere between auto-refratomer and phoropter were found to be related to the corneal curvature,(the regression coefficient is -0.07, P=0.009, P < 0.01). The differences of sphere between waverfront analyzer and phoropter were found to be respectively related to high order wave aberration (C7, C12 )and corneal curvature (The regression coefficient is -0.475, 0.489,-0.004,respectively, and P was 0.001, 0.001, 0.024, respectively). Conclusion: The accuracy of low order wave aberration is better than that of auto-refractomer in measuring refraction especially after surgery. The differences of which the accuracy of preoperative and postoperative measurement of the same eye with three instruments mainly relates to the changes of curvature of the cornea and higher-order aberrations after the excimer laser corneal refractive surgery.