J Korean Ophthalmol Soc.  1999 Feb;40(2):354-360.

Evaluation of Astigmatism Induced by Spherical LASIK

• Lim HT
• Tchah H

Abstract

The purpose of the study is to evaluate the induced astigmatism after spherical LASIK operations. A total of 36 eyes of 33 patients were treated with a Automated keratome and VISX 20/20 excimer laser. The postoperative 1 month, 3 months, and 6 months astigmatic refractive outcomes were compared with the initial refraction by vector analysis (Alpins and Holladay method). Subjective astigmatic refraction reduced from a mean of 0.48D+/-SD 0.49D(range, 0 to 1.75D) to 0.34D+/-SD 0.54D(range, 0 to 2.0D) at postoperative 6 months.Surgically induced astigmatism(SIA) had a mean of 0.53+/-0.69D(range: 0~2.49D) at 1 month, 0.49+/-0.61D(range: 0~2.79D) at 3 months, 0.62+/-0.72D(range: 0~3.14D) at 6 months follow-up. Mean SIA increased with increasing preoperative astigmatism by 0.45D SIA for every 0.5D of preoperative cylinder(Correlation coefficient: 0.618). The authors show that spherical LASIK corrections can induce significant astigmatic change, particularly if a large amount of preoperative astigmatism is present.

Keyword

Astigmatism; Spherical LASIK; Surgically induced astigmatism

MeSH Terms

Astigmatism*
Follow-Up Studies
Humans
Keratomileusis, Laser In Situ*
Lasers, Excimer