Korean J Ophthalmol.  2004 Jun;18(1):29-34. 10.3341/kjo.2004.18.1.29.

The Efficacy of Multi-Zone Cross-Cylinder Method for Astigmatism Correction

• Shin SJ
• Lee HY

• KMID: 1115780
• DOI: http://doi.org/10.3341/kjo.2004.18.1.29

Abstract

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 crosscylinder 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.

Keyword

astigmatism; LASIK; multi-zone cross-cylinder method

MeSH Terms

Adult
Astigmatism/*surgery
Corneal Stroma/surgery
Humans
Keratomileusis, Laser In Situ/*methods
Myopia/*surgery
Postoperative Complications
Prospective Studies

Figure

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  Fig. 1 The graph of postoperative mean spherical equivalent changes (D) in 6 months after cross-cylinder ablation.

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  Fig. 2 The graph of postoperative mean cylinderic changes (D) in 6 months after cross-cylinder ablation.

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  Fig. 3 Myopic with-the-rule astigmatism corrected with a cross-cylinder method. The surgical strategy involved ablating half the amount of the cylinder along steepest meridian, the other half in a subsequent step along the flattest meridian; thereafter, the spherical equivalent was corrected.

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