Astigmatism, Myopia
Conditions
Keywords
Myopia, Astigmatism, Aberrations, Wavefront, LASIK, Wavefront LASIK
Brief summary
The purpose of the study is to compare the results of LASIK surgery when using Alcon Allegretto wavefront-guided excimer laser system compared to AMO Visx Custom wavefront-guided excimer laser system in patients with nearsightedness with and without astigmatism.
Detailed description
The patients will have a comprehensive eye examination once they express an interest in the study. This includes a slit lamp examination of the front of the eye and a dilated fundoscopic examination of the back of the eye. if there is any pathology noted that would exclude the patient from the study, then we will inform the patient and make an appropriate referral. If the patient is deemed appropriate for the study after a comprehensive examination included computerized videokeratography, then they can be enrolled. The patient will undergo bilateral simultaneous eye surgery. Which eye is treated with a wavefront-guided excimer laser and which eye is treated with wavefront-optimized will be randomized so there is a 50% chance for either eye to receive one treatment. The patients will be seen on the day of surgery, post op day one, post op day 4-7, one month, three months, six months and one year. The patient will receive topical antibiotics in each eye for one week following the procedure. LASIK treated eyes will receive pred forte 1% ophthalmic drops for one week after treatment. All of this is within the usual and customary standard of care for the treatment of patients undergoing lasik surgery. The research procedures are the least risky that can be performed consistent with sound research design.
Interventions
PROCEDUREWavefront-guided LASIK - Allegretto
Wavefront-guided LASIK using the Allegretto excimer laser for myopia.
PROCEDUREWavefront-guided LASIK - AMO
Wavefront-guided LASIK using the AMO CustomVue excimer laser for myopia.
Sponsors
Stanford University
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Subjects age 21 and older with healthy eyes. * Nearsightedness between -0.50 diopters and -7.00 diopters with or without astigmatism of up to 3.50 diopters.
Exclusion criteria
* Subjects under the age of 21. * Patients with excessively thin corneas. * Patients with topographic evidence of keratoconus. * Patients with ectatic eye disorders. * Patients with autoimmune diseases. * Patients who are pregnant or nursing. * Patients must have similar levels of nearsightedness with or without astigmatism in each eye. * They can not be more than 1.5 diopters of difference between eyes. * Patients must have similar levels of astigmatism in each eye. * They can not have more than 1.5 diopters of difference in nearsightedness or astigmatism between their two eyes.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Efficacy | 1 year | Efficacy measures uncorrected visual acuity following the LASIK surgery. We will record how many eyes see 20/40, 20/30, 20/25, 20/20, 20/16, 20/12.5 and 20/10 after the surgery without glasses or contact lenses. We are measuring how well patients see after the surgery without glasses or contact lenses. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Low contrast visual acuity | 1 year | Measuring changes in best spectacle corrected low contrast visual acuity (5 and 25 percent). |
| Higher order aberrations | 1 year | Measure changes in higher order aberrations. |
| Safety | One year | Will will assess safety by measuring change in best spectacle corrected visual acuity. We will record the number of eyes that gain, lose or have no change in the best spectacle corrected visual acuity after the surgery. This is measured using snellen visual acuity charts. The ideal outcome would be that there were no loss of any lines of best spectacle corrected visual acuity and a high percentage of gains of lines of best spectacle corrected visual acuity. |
| Predictability | One year | Percentage of eyes within +/- 0.5 diopters of the intended correction |
Countries
United States
Outcome results
None listed