Efficacy of laser in situ keratomileusis in correcting anterior and non-anterior corneal astigmatism: Comparative study

Lance Kugler, MD , Ilan Cohen, MD, Walid Haddad, MD, Ming X. Wang, MD, PhD

Journal of Cataract & Refractive Surgery, Volume 36, Issue 10, Pages 1745-1752 (October 2010)

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Purpose

To compare the efficacy of conventional laser in situ keratomileusis (LASIK) in treating corneal astigmatism and in treating noncorneal ocular residual astigmatism.

Setting

Private practice, Nashville, Tennessee, USA.

Design

Retrospective case series.

Methods

The records of dominant eyes of consecutive patients who had LASIK were retrospectively analyzed to compare the efficacy of LASIK in eyes with predominantly anterior corneal astigmatism with the efficacy in eyes with predominantly ocular residual astigmatism (ORA). The ORA was determined by vector analysis using refractive cylinder and topographic astigmatism. Preoperatively, the ratio of ORA to preoperative refractive cylinder (R) was used to divide the patients into 2 groups; that is, eyes with predominantly anterior corneal astigmatism (ORA/R ratio <1.0) and eyes with predominantly ORA (ORA/R ratio ≥1.0). Efficacy was determined by examining the magnitude of the remaining uncorrected astigmatism and comparing the index of success (proportion of preoperative refractive astigmatism that remained uncorrected by LASIK) between the 2 groups.

Results

The study evaluated 61 eyes of 61 patients. Conventional LASIK was twice as efficacious in the low-ORA group as in the high-ORA group. The index of success was 0.24 and 0.50, respectively, and the difference between groups was statistically significant (P = .036).

Conclusion

The efficacy of astigmatic correction by LASIK was significantly higher in eyes in which the preoperative refractive astigmatism was located mainly on the anterior corneal surface than in eyes in which it was mainly located posterior to the anterior corneal surface.
Financial Disclosure

No author has a financial or proprietary interest in any material or method mentioned.

From Wang Vision 3D Cataract and LASIK Center (Kugler, Wang), Nashville, Tennessee, and Eye Physicians of Central Jersey (Cohen), Old Bridge, New Jersey, USA; Gefinor Center (Haddad), Beirut, Lebanon

Corresponding author: Lance J. Kugler, MD, LaserVision Correction, 13923 Gold Circle #100, Omaha, Nebraska 68144, USA.

 Jessica Chan and Lillian Tseng worked on this project with the authors.

PII: S0886-3350(10)01181-8

doi:10.1016/j.jcrs.2010.05.014

© 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.