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

A Prospective Randomized Comparison of SMILE Surgery to Ray Tracing-Guided LASIK Surgery

Status
Recruiting
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07721714
Enrollment
62
Registered
2026-07-23
Start date
2026-08-05
Completion date
2029-07-31
Last updated
2026-08-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Astigmatism, Myopia

Keywords

Ray-tracing, LASIK, SMILE

Brief summary

Participants will undergo LASIK surgery in one eye using ray tracing guided technology in one eye and LASIK surgery in the other eye using wavefront guided technology. We are comparing outcomes between the two technologies as measured by self reported quality of vision and quality of life outcomes using validated questionnaires before and after surgery. We will also be comparing outcomes between the two technologies including measurement of low contrast visual acuity,and best spectacle corrected visual acuity.

Detailed description

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.

Interventions

DEVICERay tracing guided LASIK surgery

LASIK

Sponsors

Stanford University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

Prospective, randomized, contralateral fellow eye study

Eligibility

Sex/Gender
ALL
Age
22 Years to 59 Years
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frameDescription
Change in corrected distance visual acuityThree monthsThe primary endpoint will be the gain in lines of corrected distance visual acuity (CDVA) at the postoperative month three follow-up compared with preoperative baseline.

Secondary

MeasureTime frameDescription
Change in 5 and 25% low contrast CDVAThree monthsChange in 5 and 25% low contrast best corrected visual acuity from preoperative to postoperative month three
Change in patient self reported quality of vision and lifeThree monthsWill compare preoperative quality of vision and quality of life as measured by the validated Patient Reported Outcomes With LASIK (PROWL) questionnaire to postoperative month three.
Corneal epithelial thickness changesThree monthsMeasure corneal epithelial thickness maps preoperatively and compare changes at postoperative month three
Change in higher order aberrationsThree monthsWill measure preoperative higher order aberrations using wavefront aberrometry and compare to postoperative month three measurements

Countries

United States

Contacts

CONTACTEdward E Manche, MD
edward.manche@stanford.edu1-650-498-7020

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 27, 2026