Abstract
Purpose: :
Laser epithelial keratomileusis (LASEK), a relatively new alternative to PRK, was developed to reduce complications arising from the surgical creation of a corneal flap during the LASIK procedure. Increased exposure of the corneal stroma to cytokines due to an absence of epithelium during the healing response can result in haze and reduce the predictability and stability of the refractive prescription. It is not clear whether LASEK can avoid these problems and whether it provides a significant benefit to the recipient.
Methods: :
A retrospective analysis was performed on 191 eyes of 99 patients who underwent LASEK. Of this cohort, 162 eyes of 84 patients were available for 3 month and 127 eyes of 66 patients were available for 6 month follow-up. Procedures were performed on patients whose spherical equivalent refractions were from plano to -8.00 diopters (D). LASEK was performed with a 30" exposure of a 20% solution of dehydrated ETOH in sterile water. Ablations were created with a Visx Star 4 or Star 4 IR platform using standard ablation, Customvue©, or Customvue IR©. Ablations deeper than 100 microns were treated post-operatively with a 15" exposure of 0.02% Mitomycin C. Bio-microscopy was performed at every post-operative visit while both refraction and bio-microscopy were performed at every post-operative visit beginning with week 2.
Results: :
No significant differences were found in refractions performed at 3 months or 6 months. Six month data on all LASEK corrections revealed 89% of eyes were corrected to a spherical equivalent (SEQ) of ± 0.50 D and 95% of eyes were corrected to a SEQ of ± 1.00 D. Customvue© corrections in the LASEK group <= 5 D had post-operative 6 month refractions (SEQ) in 93% of patients within ± 0.50 and 95% within ± 1.00 with a average physician adjustment of -0.10 D. In the Customvue© group > 5 D the results dropped to 77% within ± 0.50 D and 91% within ± 1.00 D, with an average physician adjustment of -0.13 D. This was largely the result of a number of over-corrections in the sub-group (n=18) with pre-operative refractions greater than -6 D. No cases of corneal haze greater than a trace were noted in any eyes. All eyes maintained a best-corrected visual acuity (BCVA) of 20/20.
Conclusions: :
LASEK provides a predictable alternative to LASIK with similar refractive outcomes. Post-operative prescriptions were stable between 3 and 6 months and no loss of BCVA or development of clinically significant haze were documented in the study patients.
Keywords: refractive surgery: other technologies • refractive surgery • refractive surgery: LASIK