Comparison of the ORK-CAM corneal wavefront-guided and the conventional LASIK for myopic correction

Objective To evaluate the outcomes of ORK-CAM corneal wavefi'ont-guided myopic LASIK and compare with the results after conventional ablation.Methods This retrospective study involved 149 eyes of 75 patients that underwent LASIK treatments for myopia and myopic astigmatism.Eighty-one eyes of 41 patients were treated with corneal wavefront-guided ablation managed by ORK-CAM 2.0.The other 68 eyes of 34 patients underwent conventional ablations.The corneal topographies were obtained with the OPTIKON SCOUT 2000 topography system.The patients' information were record preoperatively and 6 months postoperatively respectively including UCVA,refractive error,corneal asphericity,RMSh,RMS3-RMS7,spherical aberration,coma and trefoil.The difference of these items before and after treatment,also between groups was analyzed.Results The shape of anterior corneal surface changed from prolate preoperatively to oblate postoperatively in both groups.The change of corneal asphericity in ORK-CAM group was significantly lower than in conventional LASIK group.The corneal higher-order aberrations increased significantly after surgery in both groups.The postoperative RMSh,RMS3,RMS4,spherical aberration and trefoil in ORK-CAM group were significantly lower than in conventional LASIK group.Corneal wavefront-aberration guided ablation induced higher postoperative secondary spherical aberration resulted in the significantly higher post-op RMS6 in ORK-CAM group.Corneal asphericity had positive correlation with the corneal spherical aberration.Conclusions ORK-CAM corneal wavefront-aberration guided ablation could minimize the abnormal increase of corneal higher-order aberrations after the myopic LASIK.The less oblate anterior corneal surface could be anticipated after custom ablation compared with the conventional treatment.These might ensure better visual performance of the patients after the excimer laser corneal refractive surgery. Key words: Cornea; Wavefront-aberration; LASIK; Corneal aspherictiy