Astigmatism, Myopia, Myopic Astigmatism
Conditions
Keywords
KLEx, LASIK, FS-LASIK, Refractive Surgery, Astigmatism, Myopia
Brief summary
FemtoLASIK is a type of laser eye surgery used to correct vision problems such as nearsightedness, farsightedness, and astigmatism. It involves two main steps: creating a flap and reshaping the cornea. Refractive lenticule extraction, (KLEx) is another laser eye surgery method to correct vision issues, which involves creating and extracting a lenticule without the need of a flap. The investigators will evaluate and compare the efficacy and safety of these two procedures.
Detailed description
Keratorefractive lenticule extraction (KLEx) is a refractive surgery technique that does not require the creation of a flap to correct the defects. The potential advantages of this technique are related to the absence of a flap, which could make it the gold standard of refractive surgery. On the other hand, femtosecond-assisted laser in-situ keratomileusis (FS-LASIK) is the most widely practiced refractive surgery worldwide, as it offers excellent visual outcomes but does require the creation of a flap to correct the defects. The objective of this study is to evaluate the effectiveness and safety of KLEx versus FS-LASIK as a treatment option in patients with myopia or compound myopic astigmatism. This is a prospective randomized study. A total of 80 participants will be randomized into two groups, the KLEx group and FS-LASIK group. Following randomization, participants will be followed on the first day after the surgery, 1 week, 1, 3, 6, and 12 months. The primary outcome is the refractive predictability at every postoperative point after surgery, which is the proportion of the number of eyes achieving a postoperative spherical equivalent within ± 0.5 diopters of the intended target. Secondary outcome parameters include quality vision measurements, refraction, visual acuity, and adverse events.
Interventions
PROCEDUREFS-LASIK procedure
For the FS-LASIK technique, the following steps will be followed: application of topical anesthesia to mitigate discomfort and pain throughout the procedure, and the patient will be covered with a sterile drape. Subsequently, the patient will be aligned to artificially flatten the entire corneal surface, ensuring head stability with a slight tilt to optimize surgical access and avoid nasal interference. The femtosecond laser system use will be the ATOS operating system (Schwind eye-tech-solutions, Mainparkstraße 6-10, 63801 Kleinostheim, Germany), which is responsible for creating a corneal incision to create the flap, with controlled precision to ensure proper separation of corneal layers. The excimer laser will be the Amaris (Schwind eye-tech-solutions, Mainparkstraße 6-10, 63801 Kleinostheim, Germany), responsible for performing refractive correction on the cornea through selective photoablation. Following photoablation, the flap will be carefully repositioned, and upon completion o
PROCEDUREKLEx
For the KLEx technique, the following steps will be followed: after topical anesthesia, a sterile drape is placed over the patient, and a speculum is inserted into the eye, centered, and aligned with a curved interface cone before applying suction. The laser used will be the ATOS operating system (Schwind eye-tech-solutions, Mainparkstraße 6-10, 63801 Kleinostheim, Germany), which performs photo-dissection starting from the posterior surface of the refractive lenticule, followed by the creation of the lenticule edge. The anterior surface of the refractive lenticule is formed by extending beyond the posterior diameter of the lenticule by 0.5 mm to form the anterior flap, followed by a peripheral cut. Specific FS laser parameters are employed for each patient. Subsequently, the suction is released, and a Siebel spatula is used to separate and reflect the flap. Finally, the refractive lenticule is extracted using toothless forceps through the small incision. Once the procedure is complete
Sponsors
Instituto de Oftalmología Fundación Conde de Valenciana
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Masking description
Allocation sequence concealment will be done with sealed opaque envelopes. The envelope will be open prior to the intervention only to surgical team. The technique will not be known by the patient or the staff responsible of the follow-up.
Eligibility
Sex/Gender
ALL
Age
21 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Age 21 years or older * Corneal tomography without alterations * Myopia between -0.50 and -12.00 D * Astigmatism between -0.50 and -6.00 D
Exclusion criteria
* Previous eye surgeries * Pregnancy * Progressive or unstable myopia and/or compound myopic astigmatism * Ocular surface disease
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Uncorrected Visual Acuity | Day 1, week 1, months 1, 3, 6 & 12th after surgery. | Visual acuity without correction after surgery. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Postoperative spherical equivalent | Day 1, week 1, months 1, 3, 6 & 12th after surgery. | Overall refractive power that has both spherical and cylindrical components. |
| Corrected Distance Visual Acuity | Day 1, week 1, months 1, 3, 6 & 12th after surgery. | Visual acuity after surgery with refractive correction |
| Loss of 2 or more lines of BCVA | Day 1, week 1, months 1, 3, 6 & 12th after surgery. | Loss of 2 or more lines of best corrected visual acuity |
| Eyes with 0.5 Diopters within refractive target. | Day 1, week 1, months 1, 3, 6 & 12th after surgery. | Proportion of eye within 0.5 Diopters of refactive target. |
| Corneal aberrations over a 5-mm pupil | Day 1, week 1, months 1, 3, 6 & 12th after surgery | Corneal aberrations will be evaluated as the root mean square (RMS) values derived from Zernike polynomial coefficients. Parameters will include total higher-order aberrations (HOA-RMS), spherical aberration, and coma. Measurements will be obtained using the MS-39 anterior segment optical coherence tomography (OCT) system (CSO, Florence, Italy) |
| Epithelial thickness | Day 1, week 1, months 1, 3, 6 & 12 after surgery | Epithelial remodeling will be assessed using the MS-39 anterior segment optical coherence tomography (OCT) system (CSO, Florence, Italy). Epithelial thickness (µm) will be measured in five sectors-central, nasal, superior, inferior, and temporal. |
| Ocular Surface Disease Index (OSDI) score | Week 1, months 1, 3, 6 & 12 after surgery | The Ocular Surface Disease Index (OSDI) questionnaire, validated for the Mexican population, will be administered to assess ocular discomfort, visual symptoms, and environmental triggers associated with dry eye disease. |
Countries
Mexico
Outcome results
None listed