The efficacy of multi-zone cross-cylinder method for astigmatism correction

The purpose of this study is to assess the efficacy of the multi-zone cross-cylinder method as compared with the single method for astigmatism correction using LASIK. This prospective study enrolled 40 patients (52 eyes) who underwent the cross-cylinder method using LASIK, and 52 patients (60 eyes) who underwent the single method using LASIK: all patients were given a diagnosis of complex myopic astigmatism from the department of ophthalmology of this hospital between January 2002 and July 2003. Preoperatively, the mean spherical equivalent refraction was -3.85 +/- 1.13 D in the cross-cylinder group and -4.05 +/- 1.20 D in the single method group (p = 0.23). The mean cylinder was -2.05 +/- 1.58 D in the cross-cylinder group and -1.95 +/- 1.12 D in the single method group (p = 0.31). 6 months after treatment the results were a mean spherical equivalent refraction of -0.26 +/- 0.30 D in the cross-cylinder group and -0.34 +/- 0.35 D in the single method group (p = 0.13). The mean cylinder was -0.38 +/- 0.29 D in the cross-cylinder group and -0.45 +/- 0.30 D in the single method group (p = 0.096). There were no statistically significant differences between the two groups. The mean BCVA was not different from mean preoperative BCVA in both groups (i.e., 0.98 +/- 0.10, 0.96 +/- 0.25, p = 0.86). Postoperatively, patient complications that included night halo, glare and corneal haze were not noted in either group. In conclusion, the results of cross-cylinder method are no different from the single method for the correction of a complex astigmatism. In the future, studies will have to be conducted to assess the efficacy of the cross-cylinder method in consideration of those factors that can affect the postoperative outcome.