LASEK, Epi-LASIK and PRK produce similarly good refractive and visual outcomes when used to correct myopia with a wavefront-guided excimer laser. That’s the finding of researchers at the University of Ottawa Eye Institute in Canada.
In the study, 998 eyes with nearsightedness ranging from -1.00 to -8.00 diopters (D) were treated at the university eye center using one of the following laser eye surgery procedures: LASEK, Epi-LASIK, PRK and Epi-PRK.
LASEK, Epi-LASIK and PRK: Study design
In the LASEK and PRK groups, the corneal epithelium was first loosened from the underlying corneal tissue with a 20 percent alcohol solution for 20 seconds. In the LASEK group, the flap was reapplied to the eye after the wavefront-guided excimer laser treatment; in the PRK group, the flap was removed and discarded.
In the Epi-LASIK and Epi-PRK groups, a hand-held surgical tool called a MicronEdge Separator, (Gebauer Ophthalmic Instruments, North Palm Beach, Fla.) was used to create the epithelial flap. In the Epi-LASIK group, the flap was reapplied to the cornea after the laser treatment; in the Epi-PRK (also called flap-off Epi-LASIK) group, the flap was removed and discarded.
In all procedures, the wavefront-guided laser ablation was performed with a VISX Star S4 IR excimer laser (Abbott Medical Optics, Santa Ana, Calif.).
All eyes were evaluated for a period of one year after surgery, and measures of uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA) were taken before surgery and throughout the post-operative period.
Results
Analysis of the data one year after surgery revealed that there was no statistically significant difference in proportion of eyes achieving UCVA of 20/20 or better and BSCVA of 20/20 or better among the four surgical groups.
Refractive results were found to be very stable in all surgery groups, and outcomes were within 0.50 D of the intended correction in at least 96 percent of eyes in all groups.
Sadhana Kulkarni, MD, presented the results of the study at the annual meeting of the American Society of Cataract and Refractive Surgery (ASCRS) this week in San Francisco.
SOURCE: Large retrospective study explores best technique for wavefront-guided surface ablation. Ophthalmology Times. Published online April 5, 2009.