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Randomized Controlled Trial
. 2012 Dec;38(12):2125-30.
doi: 10.1016/j.jcrs.2012.07.034. Epub 2012 Oct 13.

Corneal endothelial cell changes 5 years after laser in situ keratomileusis: femtosecond laser versus mechanical microkeratome

Kyle N Klingler  1 , Jay W McLaren, William M Bourne, Sanjay V Patel
Affiliations
Randomized Controlled Trial

Corneal endothelial cell changes 5 years after laser in situ keratomileusis: femtosecond laser versus mechanical microkeratome

Kyle N Klingler et al. J Cataract Refract Surg. 2012 Dec.

Abstract

Purpose: To compare corneal endothelial cell density (ECD) and morphology between flap creation with a femtosecond laser and flap creation with a mechanical microkeratome 5 years after laser in situ keratomileusis (LASIK).

Setting: Mayo Clinic, Rochester, Minnesota, USA.

Design: Prospective randomized masked paired-eye study.

Methods: In this study of LASIK for myopia or myopic astigmatism, fellow eyes were randomized by ocular dominance to flap creation by a femtosecond laser or by a mechanical microkeratome. Central endothelial images were analyzed before and 3 years and 5 years after LASIK; endothelial cell variables were compared between treatments at each examination. Relationships between endothelial cell loss and contact lens wear, residual bed thickness, and preoperative refractive error were evaluated.

Results: There were no differences in the ECD, percentage of hexagonal cells, or coefficient of variation of cell area between treatments at any examination (all P = .99); the smallest detectable differences were 120 cells/mm(2), 5%, and 2%, respectively. The mean annual rate of corneal endothelial cell loss was -0.1% ± 1.2% (SD) and -0.1% ± 1.0% for the femtosecond laser and the mechanical microkeratome, respectively. Endothelial cell loss was not associated with contact lens wear, residual bed thickness, or preoperative refractive error.

Conclusions: The energy delivered to the cornea during femtosecond laser flap creation did not affect the corneal endothelium 5 years after LASIK when compared with flap creation with a mechanical microkeratome. Corneas that have had either method of flap creation could be accepted as donor tissue for endothelial keratoplasty from the standpoint of endothelial health.

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

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Figures

Figure 1
Figure 1
Relationship between endothelial cell loss after LASIK and preoperative refractive error (N = 35).
Figure 2
Figure 2
Relationship between endothelial cell loss and residual bed thickness after LASIK (N = 35).
See this image and copyright information in PMC

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Other Cited Material

    1. A. National Institutes of Health Clinical Trials. [Accessed August 12, 2012];Long-term effects of laser refractive surgery. :NCT00350246. Available at: http://www.clinicaltrials.gov/ct2/show/NCT00350246?term=NCT00350246&rank=1.

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