Astigmatism, Myopia
Conditions
Keywords
Ray tracing-guided LASIK, Wavefront-guided LASIK
Brief summary
We are enrolling participants aged 22 and older to have LASIK surgery in both eyes. We will perform wavefront-guided LASIK in one eye and ray tracing-guided LASIK in the fellow eye of each participant. We are trying to see if there are any differences in the efficacy between the two types of LASIK procedures.
Detailed description
We are comparing the outcomes of wavefront-guided LASIK (laser in-situ keratomileusis) and ray tracing-guided LASIK for nearsightedness with and without astigmatism. Wavefront aberrometry (a non-contact laser measuring device) is an automated device that measures the refractive status of the eye. This data is then transferred to the laser system and calculates a unique treatment to reduce or eliminate your nearsightedness with and without astigmatism (a non-spherical shape). One eye will be treated with ray tracing-guided LASIK and the other eye treated with the wavefront-guided LASIK. Each participant will receive both wavefront-guided LASIK and ray-tracing guided LASIK. Both wavefront-guided LASIK and ray tracing-guided LASIK are FDA-approved procedures. Both procedures are being performed according to the FDA-approved labeling. We plan to enroll up to 70 near-sighted study participants to undergo treatment in this clinical research trial. The choice of which eye receives ray tracing-guided LASIK surgery and which eye receives wavefront-guided LASIK will be randomized (assigned at random) prior to enrollment. Participants scheduled to undergo LASIK 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 a participant elects to undergo a re-treatment of the initial LASIK surgery prior to the 12-month post-operative visit, the data after the retreatment procedure will be excluded from the study analysis. The primary aim of the research is to compare outcomes between the two procedures. All of the procedures performed during the study are considered standard of care for LASIK surgeries.
Interventions
PROCEDURELASIK
Wavefront-guided LASIK is being performed in one eye and Ray-tracing guided LASIK is being performed in the fellow eye
Sponsors
Stanford University
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
This is a prospective, randomized, contralateral fellow eye study comparing ray-tracing guided LASIK in one eye to wavefront-guided LASIK in the fellow eye of participants
Eligibility
Sex/Gender
ALL
Age
22 Years to 59 Years
Healthy volunteers
Yes
Inclusion criteria
1. Age 22 and older 2. People with healthy eyes: 1. No abnormal corneal shape 2. No excessively thin corneas 3. No eye diseases such as glaucoma or cataracts 3. Nearsightedness between -1.00 diopters and -10.00 diopters. 4. Subjects with less than or equal to 3.00 diopters of astigmatism. 5. Subjects must have similar levels of nearsightedness in each eye.
Exclusion criteria
1. Subjects under the age of 22. 2. Subjects with excessively thin corneas. 3. Subjects with topographic evidence of keratoconus. 4. Subjects with ectactic eye disorders. 5. Subjects with autoimmune diseases. 6. Subjects who are pregnant or nursing at the time of surgery. (The FDA-approved labelling indications for LASIK specifically excludes patients who are pregnant or nursing. There is no strict prohibition not to become pregnant during the one year study period) 7. They can not be more than 1.5 diopter of difference between eyes. 8. Subjects with more than 3.00 diopters of astigmatism 9. Subjects with disimilar levels of astigmatism in each eye (They can not have more than 0.75 diopters of difference between eyes) -
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Uncorrected visual acuity | One year | Uncorrected visual acuity using ETDRS charts |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 5 and 25% best corrected low contrast visual acuity | 12 months | Measurement of the change in 5 and 25% best corrected low contrast visual acuity using ETDRS charts |
| Achieved versus attempted ablation depth measured by anterior segment OCT | One, three and twelve months | Measurement of achieved ablation depth by comparing preoperative anterior segment OCT to postoperative anterior segment OCT |
| Self reported quality of vision and quality of life measures | Three, six and twelve months | A validated questionnaire will be administered preoperatively and at postoperative months 3, 6 and 12 |
Countries
United States
Contacts
CONTACTEdward E Manche, MD
CONTACTTheresa Enriquez, HS
PRINCIPAL_INVESTIGATOREdward E Manche, MD
Stanford University
Outcome results
None listed