70 vs 110 Degree Side-cut Angles in Femtosecond LASIK

Study Overview
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Brief Summary
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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
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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.

Official Title
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70 Versus 110 Degrees Side-cut Angles in Femtosecond Laser-assisted in Situ Keratomileusis

Conditions
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Operative Incision

Intervention / Treatment
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* Device: FS-LASIK 70 degree side-cut angle
* Device: FS-LASIK 110 degree side-cut angle


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 21 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: FS-LASIK 70 degree side-cut angle<br>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. | Device: FS-LASIK 70 degree side-cut angle<br>* 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.<br>Device: FS-LASIK 110 degree side-cut angle<br>* 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.<br>|
| Active Comparator: FS-LASIK 110 degree side-cut angle<br>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. | Device: FS-LASIK 70 degree side-cut angle<br>* 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.<br>Device: FS-LASIK 110 degree side-cut angle<br>* 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.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Uncorrected Visual Acuity at One Year | Vision testing without correction, both eyes using Snellen Eye chart | one year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Best Corrected Visual Acuity at Year One | Vision testing with correction, both eyes using Snellen Eye chart | one year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Femtosecond LASIK (FS--LASIK), Visual acuity, Refractive errors, Side-cut angles