RESUMO
Objective To compare the efficacy and predictability of sphere-cylinder-combined LASIK and two-zone cross-cylinder LASIK for the correction of moderate and high astigmatism.Design Prospective,comparative case series.Participants 40 eyes of 35 patients with mixed astigmatism undergoing LASIK.Methods All patients were treated with Visx Star IV LASIK system.20 eyes of 19 cases were used for sphere-cylinder combined LASIK mode and 20 eyes of 16 cases for two-zone-cross-cylinder LASIK mode.All sub- jects were followed more than 6 months.Main Outcome Measures Uncorrected visual acuity (UCVA),best spectacle-corrected visual acuity (BSCVA),spherical diopter,residual astigmatism and corneal thickness.Results For the patients who received two-zone-cross-cylinder LASIK mode,the UCVA at 6 months after surgery was 0.5 or above,and 13 eyes (65.0%) were 1.0 or above. For the patients who received sphere-cylinder-combined LASIK mode,the UCVA at 6 months after surgery was 0.5 or above,and 11 eyes (55.0%) was 1.0 or above (P=0.683).The residual astigmatism for the patients received sphere-cylinder-combined LASIK mode was (1.15?1.00)D,while for the patients received cross-cylinder LASIK mode was (1.13?0.62)D(P=0.045).The remotion depth of cornea for sphere-cylinder-combined LASIK mode and cross-cylinder LASIK mode was (36.73?13.12)?m and (15.60?6.85)?m,respectively (P= 0.031).Condusion The UCVA,residual astigmatism and corneal thickness after surgery in two-zone-cross-cylinder LASIK mode were better than that in sphere-cylinder-combined LASIK mode for the correction of moderate and high astigmatism.