SMILE Surgery in One Eye Compared to Ray Tracing-guided LASIK Surgery in the Fellow Eye

Sixty-two near-sighted study participants at Stanford are planned to undergo treatment in this clinical research trial.

This comparison will be made between both eyes of the same study participant following LASIK and SMILE surgery. One eye will have ray tracing-guided LASIK and their fellow eye treated with SMILE surgery. Both ray tracing-guided LASIK surgery and SMILE surgery have been found to be safe, predictable and effective when used for laser vision correction procedures. Both ray tracing-guided LASIK surgery and SMILE surgery used in this study have been approved for laser vision correction by the United States Food and Drug Administration. Standard refractive outcomes such as uncorrected visual acuity (vision without glasses or contact lenses) and best corrected visual acuity (vision with glasses or contact lenses), and intended vs. achieved postoperative refractions (the accuracy of the LASIK and SMILE procedures) will be evaluated.

Randomization:

The choice of which eye receives ray tracing-guided LASIK surgery and which eye receives SMILE surgery will be randomized (assigned at random) prior to enrollment. Participants will have one eye treated with ray tracing-guided LASIK and your other eye treated with the SMILE surgery. Participants will know which eye is being treated with ray tracing-guided LASIK and which eye will be treated with SMILE surgery. Both ray tracing-guided LASIK and SMILE surgery are FDA-approved procedures. Both procedures are being performed according to the FDA-approved labeling. Participants have a fifty percent chance of having their left eye treated with ray tracing-guided LASIK as their right eye (like making a choice by flipping a coin). Participants will undergo bilateral (both eyes at once) surgery.

Screening and Preoperative Assessment Participants will be partially screened via telephone. We will also ask participants to complete screening by coming to the clinic in person. This screening will include measurements of corneal thickness, the shape of the cornea using corneal topography (measures the shape of the front clear surface of the eye), a slit lamp examination of the eye (a microscope to magnify the cornea) and ocular and medical history.

Participants scheduled to undergo LASIK and SMILE surgery for the correction of myopia (nearsightedness) will be screened for eligibility. Eligible participants will be examined preoperatively to establish a baseline for ocular condition (the general health and glasses prescription of the eyes). Postoperatively, participants will undergo an ophthalmic evaluation (complete eye examination) at regular intervals as specified in this protocol. Re-treatments (a second operation on the same eye for residual nearsightedness, farsightedness and/or astigmatism) 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 data after the retreatment procedure will be excluded from the study analysis.

Participants eyes will be given a thorough examination at each visit. This examination will include the standard elements of a general eye exam including testing of the eye's vision, contrast acuity testing, examination with the slit lamp and the ophthalmoscope to look at the various parts of the eye and a test of the inner eye's pressure.

Inclusion criteria

Subjects age 22 and older with healthy eyes. Nearsightedness between -1.00 diopters and -8.00 diopters.

Subjects with less than or equal to 3.00 diopters of astigmatism.

Exclusion criteria

Subjects under the age of 22. Subjects with excessively thin corneas. Subjects with topographic evidence of keratoconus. Subjects with ectactic eye disorders. Subjects with autoimmune diseases. Subjects who are pregnant or nursing. Subjects must have similar levels of nearsightedness in each eye. They can not be more than 1.5 diopter of difference between eyes.

Subjects with more than 3.00 diopters of astigmatism Subjects must have similar levels of astigmatism in each eye. They can not have more than 0.75 diopters of difference between eyes.