An interventional study of SMILE surgery and FS-LASIK surgery in Refractive Error, sponsored by Tianjin Eye Hospital. Status unknown at 1 site in China. Open to participants aged 18 Years to 45 Years. Per ClinicalTrials.gov, last updated 2018-05-04.
Sponsored by Tianjin Eye Hospital · Not applicable, Interventional, and Treatment
The purpose of this study is to carry out an international multicenter trial to get more convincing and valuable results of the SMILE surgery and compare the outcomes between the SMILE surgery and the FS-LASIK (femtosecond laser assisted-laser in situ keratomileusis) surgery.
The investigators hope to investigate the differences between the SMILE and the FS-LASIK surgery comprehensively, including the comparison of visual acuity, refraction, the correction of cylindrical diopter, the high order aberrations, the corneal biomechanics, the corneal ectasia, the characteristics of the changes of central corneal thickness and the complications. To meet the demands of a multi center trial, all the examination equipments should be same in each center, and this will limit the variations within a study
Hypothesis: To compare the novel refractive surgery (SMILE, the intervention group) with traditional refractive surgery (FS-LASIK, the control group) in terms of visual acuity, the higher order aberrations, corneal biomechanical parameters and the complications. SMILE surgery might offer some advantages in some aspects compared with FS-LASIK surgery.
Study program
The procedures of the study are listed as follows:
All the participants accept the refractive surgery which were selected at first, and patients' routine postoperative examinations included UCVA, BCVA, slit lamp microscopy, non-contact IOP, corneal topography with the Scheimpflug tomography system, ocular higher order aberrations using the WASCA analyzer (Carl Zeiss Meditec AG), corneal biomechanical properties acquired by the Ocular Response Analyzer and/or the Corvis ST (Corvis ST, OCULUS, Wetzlar, Germany) at 1 week, 1 month, 3 months and 6 months follow-up periods after surgery.
Statistics:
Patients who have decided to choose the SMILE surgery or the FS-LASIK will be selected as participants. The propensity matching method will be used to choose proper cases for the two groups. The propensity matching method can be calculated by SPSS software. The independent variables include: the central corneal thickness (CCT), the Km (mean Pentacam keratometry), the spherical diopter (from manifest refraction), and the cylindrical diopter (from manifest refraction), the UCVA, the BCVA, the corneal resistance factor (CRF) and the corneal hysteresis (CH) (if the investigator have the Ocular Response Analyzer) of the cornea at preoperative. The closest score of eyes in the two groups will be matched.
The data will be preserved by each site, and will be systematically collected and analyzed by TianjinEH center. The statistical expert Dr Hayes from American Pacific University will be the statistical consultant, and will also in charge of the sample size calculation, the instructor of statistical analysis, and the quality control.
413 studies on the registry are indexed under Refractive Errors; 62 are open to participants now.
This study's planned enrollment of 1,000 is above the median of 82 across 296 interventional studies indexed under Refractive Errors.
Browse Refractive Errors studies →Tianjin Eye Hospital is the lead sponsor of 49 studies on the registry; 15 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Small incision lenticule extraction (SMILE) has become a novel and effective method for the correction of myopia and myopic astigmatism. It is a micro-invasive and flapless refractive procedure that has been proved to offer many advantages in terms of visual acuity, corneal sensitivity and corneal biomechanics compared with traditional refractive surgeries.
Procedure: SMILE surgery
FS-LASIK surgery is femtosecond laser assisted- conventional refractive surgery and has also been proved to offer many advantages in terms of visual acuity, corneal sensitivity and corneal biomechanics compared with traditional refractive surgeries.
Other: FS-LASIK surgery
SMILE surgery and FS-LASIK surgery are both effective method for the correction of myopia and myopic astigmatism. They have been proved to offer many advantages in terms of visual acuity, corneal sensitivity and corneal biomechanics compared with traditional refractive surgeries.
SMILE surgery and FS-LASIK surgery are both effective method for the correction of myopia and myopic astigmatism. They have been proved to offer many advantages in terms of visual acuity, corneal sensitivity and corneal biomechanics compared with traditional refractive surgeries.
corrected visual acuity
Time frame: change from baseline with EDTRS chart at 6 months
uncorrected visual acuity
Time frame: change from baseline with EDTRS chart at 6 months
spherical diopter
Time frame: change from baseline with manifest refraction at 6 months
cylindrical dioptor
Time frame: change from baseline with manifest refraction at 6 months
central corneal thickness
Time frame: change from baseline with the Pentacam system at 6 months
corneal curvature assessed by the Pentacam system
Time frame: change from baseline with mean Pentacam keratometry at 6 months
corneal resistance factor assessed by the Ocular Response Analyzer
Time frame: change from baseline at 6 months
corneal hysteresis assessed by the Ocular Response Analyzer
Time frame: change from baseline at 6 months
deformation amplitude assessed by the Corvis ST system
Time frame: change from baseline at 6 months
spherical aberration
Time frame: change from baseline with the WASCA system at 6 months
coma aberration
Time frame: change from baseline with the WASCA system at 6 months
complication
Time frame: intraoperative and postoperative at 6 months
Plan to share: No
This study is status unknown, as verified in May 2018. You cannot join it, but the record below documents what was studied.
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Tianjin Eye Hospital