Operative Incision
Conditions
Keywords
Femtosecond LASIK (FS--LASIK), Visual acuity, Refractive errors, Side-cut angles
Brief summary
The purpose of this study is to compare 70 and 110 degree side-cut angles on the same patient undergoing Femtosecond Laser-assisted in Situ Keratomileusis (FS-LASIK).
Detailed description
LASIK has become the preferred corneal procedure to correct certain refractive errors. One of the major advancements in LASIK has been the introduction of Femtosecond Laser technology for flap creation. Several studies have compared microkeratome and femtosecond laser technology, showing superior accuracy and precision of flap dimensions in the latter. The Femtosecond Laser technology provides different parameters and settings that can be changed according to the surgeon's preference. One of such parameters is the side-cut angle. Some of the most common side-cut angles used today include 45, 70, 90, and 110 degrees. Previous studies have reported on the visual outcomes of side-cut angles, but head to head comparisons are lacking. Currently, there are no studies comparing the safety and efficacy of the 70 and 110 side-cut angles in FS-LASIK. Information regarding the outcomes and complication rates between these side-cut angles will provide an objective measure that can be used when deciding which one is more suitable in FS-LASIK. One angle will be performed on the right eye and the other on the left eye. The study will evaluate uncorrected visual acuity, best corrected visual acuity, intraoperative, and postoperative complications. Performing different side-cut angles on the same individual will allow a direct comparison of outcomes, minimizing confounding variables.
Interventions
DEVICEFS-LASIK 70 degree side-cut angle
FS-LASIK surgical procedures will be performed according to the surgeons' standard practices. Patient will be masked as to the treatment they receive in either eye so as not to influence their subjective responses and visual measurements. Patients will be discontinued from the study if, on the day of surgery, both eyes cannot be randomized and operated as per protocol.
DEVICEFS-LASIK 110 degree side-cut angle
FS-LASIK surgical procedures will be performed according to the surgeons' standard practices. Patient will be masked as to the treatment they receive in either eye so as not to influence their subjective responses and visual measurements. Patients will be discontinued from the study if, on the day of surgery, both eyes cannot be randomized and operated as per protocol.
Sponsors
University of Utah
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
SINGLE (Subject)
Masking description
Each participant will be masked as to which angle of cut is used in which eye. Each patient will receive a 70 degree cut in one eye and a 110 degree cut in the fellow eye
Eligibility
Sex/Gender
ALL
Age
21 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Subjects who are deemed suitable candidates for bilateral LASIK will be considered eligible for participation in this study. Correction will be distance for both eyes.
Exclusion criteria
* Selection will be consistent with current standard of care. Any patient that is not a suitable candidate for LASIK will not be included.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Uncorrected Visual Acuity at One Year | one year | Vision testing without correction, both eyes using Snellen Eye chart |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Best Corrected Visual Acuity at Year One | one year | Vision testing with correction, both eyes using Snellen Eye chart |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| All Participants Each patient will be masked as to which angle of cut is used in which eye. Each patient will receive a 70 degree cut in one eye and a 110 degree cut in the fellow eye.
FS-LASIK 70 degree side-cut angle: FS-LASIK surgical procedures will be performed according to the surgeons' standard practices. Patient will be masked as to the treatment they receive in either eye so as not to influence their subjective responses and visual measurements. Patients will be discontinued from the study if, on the day of surgery, both eyes cannot be randomized and operated as per protocol.
FS-LASIK 110 degree side-cut angle: FS-LASIK surgical procedures will be performed according to the surgeons' standard practices. Patient will be masked as to the treatment they receive in either eye so as not to influence their subjective responses and visual measurements. Patients will be discontinued from the study if, on the day of surgery, both eyes cannot be randomized and operated as per protocol. | 115 |
| Total | 115 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Lost to Follow-up | 68 | 68 |
| Overall Study | Physician Decision | 3 | 3 |
| Overall Study | Withdrawal by Subject | 2 | 2 |
Baseline characteristics
| Characteristic | All Participants |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 115 Participants |
| Age, Continuous | 31.96 years STANDARD_DEVIATION 6.5 |
| Race (NIH/OMB) American Indian or Alaska Native | 1 Participants |
| Race (NIH/OMB) Asian | 4 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 5 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 12 Participants |
| Race (NIH/OMB) White | 93 Participants |
| Sex: Female, Male Female | 65 Participants |
| Sex: Female, Male Male | 50 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 115 | 0 / 115 |
| other Total, other adverse events | 2 / 115 | 2 / 115 |
| serious Total, serious adverse events | 0 / 115 | 0 / 115 |
Outcome results
Primary
Uncorrected Visual Acuity at One Year
Vision testing without correction, both eyes using Snellen Eye chart
Time frame: one year
Population: This is a contralateral eye study of 115 subjects, each with one eye randomized to the two study groups.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| FS-LASIK 70 Degree Side-cut Angle | Uncorrected Visual Acuity at One Year | -0.082 logMAR Visual Acuity | Standard Deviation 0.065 |
| FS-LASIK 110 Degree Side-cut Angle | Uncorrected Visual Acuity at One Year | -0.094 logMAR Visual Acuity | Standard Deviation 0.072 |
Secondary
Best Corrected Visual Acuity at Year One
Vision testing with correction, both eyes using Snellen Eye chart
Time frame: one year
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| FS-LASIK 70 Degree Side-cut Angle | Best Corrected Visual Acuity at Year One | -0.109 logMAR Visual Acuity | Standard Deviation 0.066 |
| FS-LASIK 110 Degree Side-cut Angle | Best Corrected Visual Acuity at Year One | -0.116 logMAR Visual Acuity | Standard Deviation 0.06 |