Early Changes Among FLEx, LASIK and FS-LASIK
- Conditions
- AstigmatismMyopia
- Interventions
- Procedure: lenticule extractionProcedure: laser in situ keratomileusisProcedure: FS assisted laser in situ keratomileusis
- Registration Number
- NCT02551796
- Lead Sponsor
- Sun Yat-sen University
- Brief Summary
To evaluate the short-term changes in ocular surface measures and tear inflammatory mediators after lenticule extraction (FLEx), laser in situ keratomileusis (LASIK) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) procedures.
- Detailed Description
Laser in situ keratomileusis (LASIK) with a microkeratome has been accepted wildly in the past 20 years. Gradually, laser in situ keratomileusis with a femtosecond laser-created flap (FS-LASIK)has been a popular ophthalmic procedure for the correction of refractive error. This first all-in-one FS-laser system was designed to perform the refractive lenticule extraction (ReLEx) procedures, femtosecond lenticule extraction (FLEx).They have the same feature: corneal flap.
Ocular surface disruption during corneal refractive surgery is commonly considered to be closely related to the development of dry eye. Multiple etiologies contribute to this ocular surface disruption, including the flap creation and stromal ablation involved in previous refractive surgery techniques. Corneal nerve damage has been considered the main cause of dry eye, due to disrupted afferent sensory nerves, reduced blink reflex, and increased tear evaporation leading to tear film instability. In addition, postoperative inflammatory mediator fluctuations are also a key factor related to ocular surface damage. Extensive research has described the effects of cytokines, chemokines and growth factors in modulating corneal wound healing, cell migration, and apoptosis on the ocular surface after refractive surgery.
This prospective clinical study is going to analyze the short-term changes in ocular surface measures and tear inflammatory mediators after FLEx, LASIK and FS-LASIK procedures.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 75
- minimum age of 18 years(range from 18 year to 31 years); corneal thickness 500 μm with calculated residual stromal bed after treatment greater than 300 μm; preoperative spherical equivalent refraction between
- 2.00 diopter (D) and -6.50 D; preoperative cylindrical equivalent refraction between -0.25 D and -1.50 D; preoperative corneal curvature from 42.0 D to 46.0 D with a regular topographic pattern, verified with an Atlas topographer; monocular best corrected visual acuity of 20/20 or better and stable refractive error (less than 0.5 D change) for 24 months before surgery
- systemic disease that contraindicated the surgery (such as diabetes, glaucoma and systemic collagen vascular disease); corneal abnormality or disease; a history of tear supplement usage or contact lens wear during the past year
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description lenticule extraction lenticule extraction The patients in this group chose to receive the lenticule extraction surgery. laser in situ keratomileusis laser in situ keratomileusis The patients in this group chose to receive the laser in situ keratomileusis surgery. FS assisted laser in situ keratomileusis FS assisted laser in situ keratomileusis The patients in this group chose to receive the FS assisted laser in situ keratomileusis surgery.
- Primary Outcome Measures
Name Time Method scale of Schirmer I test up to 1month after surgery scale of corneal fluorescein staining up to 1month after surgery scale of noninvasive tear breakup time up to 1month after surgery questionnaire of ocular surface disease index up to 1month after surgery scale of central corneal sensitivity up to 1month after surgery scale of tear meniscus height up to 1month after surgery concentration of Interleukin-1α up to 1month after surgery concentration of tumor necrosis factor-α up to 1month after surgery concentration of nerve growth factor up to 1month after surgery interferon-γ up to 1month after surgery concentration of transforming growth factor-β1 up to 1month after surgery concentration of matrix metalloproteinase-9 up to 1month after surgery
- Secondary Outcome Measures
Name Time Method Correlation between interferon-γ and corneal fluorescein staining up to 1month after surgery Correlation between transforming growth factor-β1 and corneal fluorescein staining up to 1month after surgery Correlation between matrix metalloproteinase-9 and corneal fluorescein staining up to 1month after surgery Correlation between Interleukin-1α and ocular surface disease index up to 1month after surgery Correlation between tumor necrosis factor-α and ocular surface disease index up to 1month after surgery Correlation between nerve growth factor and ocular surface disease index up to 1month after surgery Correlation between interferon-γ and ocular surface disease index up to 1month after surgery Correlation between transforming growth factor-β1 and ocular surface disease index up to 1month after surgery Correlation between matrix metalloproteinase-9 and ocular surface disease index up to 1month after surgery Correlation between Interleukin-1α and corneal fluorescein staining up to 1month after surgery Correlation between nerve growth factor and corneal fluorescein staining up to 1month after surgery Correlation between tumor necrosis factor-α and corneal fluorescein staining up to 1month after surgery
Trial Locations
- Locations (1)
Hainan Eye Hospital, Zhongshan Ophthalmic Center of Sun Yat-sen University
🇨🇳Haikou, Hainan, China