Wavefront-guided Versus Wavefront-optimized LASIK for Nearsightedness

• Changes in best corrected visual acuity [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]
  
• Changes in 5 and 25% contrast visual acuity [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]
  
• Refractive predictability [ Time Frame: 12 months ] [ Designated as safety issue: No ]
  
• Uncorrected visual acuity [ Time Frame: 12 months ] [ Designated as safety issue: No ]
  

• Changes in higher order aberrations [ Time Frame: 1 yr ] [ Designated as safety issue: No ]
  
• Quality of vision measurement [ Time Frame: 1 yr ] [ Designated as safety issue: Yes ]
  
• Topographic analysis [ Time Frame: 1 yr ] [ Designated as safety issue: No ]
  

Procedure: Wavefront-guided LASIK
Wavefront-guided LASIK in one eye using the Allegretto excimer laser
Other Name: Wavelight Allegretto Eye-Q 400 Hz excimer laser
Procedure: Wavefront-optimized LASIK
Wavefront-optimized LASIK in one eye using the Allegretto excimer laser
Other Name: Wavelight Allegretto Eye-Q 400 Hz excimer laser

This is a research study comparing the outcomes of LASIK surgery for nearsightedness when using the two different excimer laser technologies. Patients will have both eyes treated with the Alcon WaveLight Allegretto excimer laser. You will be one of 150 sighted patients at Stanford to undergo treatment in this clinical research trial. This will be a prospective, randomized, research study in which up to 300 consecutive eyes scheduled to undergo excimer laser in situ keratomileusis (LASIK) using one laser technology in the first eye and the second laser technology in the fellow eye for the correction of myopia (nearsightedness) with or without astigmatism will be enrolled. The choice of which eye receives the wavefront guided technology and which eye receives the wavefront-optimized technology will be randomized prior to enrollment. Randomization will be done according to a randomization schedule. You will know which eye is being treated with which each technology. The randomization will determine only whether your right or left eye is treated with the wavefront guided technology. The other eye will be treated with wavefront-optimized laser technology. You have a fifty percent chance of having your left eye treated with custom wavefront guided technology as your right eye. Subjects will undergo bilateral (both eyes at once) LASIK treatments using the Alcon WaveLight Allegretto excimer laser. All subjects will be followed for one year after the vision correction procedure. Subjects scheduled to undergo LASIK for the correction of myopia (nearsightedness) with or without astigmatism will be screened for eligibility. Eligible subjects will be examined preoperatively to establish a baseline for ocular condition (the general health and glasses prescription of the eyes). Postoperatively, subjects will undergo an ophthalmic evaluation (complete eye examination) at regular intervals as specified in this protocol. Retreatments (a second operation on the same eye for residual nearsightedness) will not be allowed during the first twelve months of this study. If you elect to undergo a retreatment of your LASIK surgery prior to the 12-month post-operative visit, the retreated eye will be exited from the study as of the retreatment date.

Any significant new finding developed during the course of the research which may relate to the subject's willingness to continue participation will be provided to the subject or subject's representative in a timely manner.