International Multicenter Study on SMILE Surgery

May 3, 2018 updated by: Tianjin Eye Hospital

International Multicenter Study on Small Incision Lenticule Extraction(SMILE) Surgery

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

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

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.

Study Type

Interventional

Enrollment (Anticipated)

1000

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

16 years to 43 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • be accompanied by a parent or guardian who is able to give informed consent as demonstrated by signing a record of informed consent;
  • at baseline, be within the age range of 18 to 45 years old inclusive
  • normal corneal morphology with no corneal nebula or corneal macula, the range of preoperative K2 (the steep curvature of the 3mm area at the center of cornea) from 38.0 to 47.0 diopter
  • manifest spherical equivalent of -1.0 to -10.0 diopters (D)
  • cylindrical diopter no more than -5.0D
  • refractive diopter maintained stable for more than2 years
  • preoperative BCVA≥0.8, and the scotopic pupil diameter≥5.0mm when measured by WASCA analyzer (Carl Zeiss Meditec AG)
  • picked off soft contact lens for more than 2 weeks
  • picked off RGP for more than 1 month
  • preoperative corneal central thickness measured by Pentacam >500μm, non-contact IOP<21mmHg
  • be willing to comply with the clinical trial visit schedule as directed by the investigator.

Exclusion Criteria:

  • any corneal diseases, corneal operations, eyes trauma or systemic diseases history; keratoconus or tendency of keratoconus
  • corneal macula and obvious pannus; current enrolment in another clinical trial/research project.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: SMILE surgery
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
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.
Other: FS-LASIK 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
corrected visual acuity
Time Frame: change from baseline with EDTRS chart at 6 months
change from baseline with EDTRS chart at 6 months

Secondary Outcome Measures

Outcome Measure
Time Frame
uncorrected visual acuity
Time Frame: change from baseline with EDTRS chart at 6 months
change from baseline with EDTRS chart at 6 months
spherical diopter
Time Frame: change from baseline with manifest refraction at 6 months
change from baseline with manifest refraction at 6 months
cylindrical dioptor
Time Frame: change from baseline with manifest refraction at 6 months
change from baseline with manifest refraction at 6 months
central corneal thickness
Time Frame: change from baseline with the Pentacam system at 6 months
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
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
change from baseline at 6 months
corneal hysteresis assessed by the Ocular Response Analyzer
Time Frame: change from baseline at 6 months
change from baseline at 6 months
deformation amplitude assessed by the Corvis ST system
Time Frame: change from baseline at 6 months
change from baseline at 6 months
spherical aberration
Time Frame: change from baseline with the WASCA system at 6 months
change from baseline with the WASCA system at 6 months
coma aberration
Time Frame: change from baseline with the WASCA system at 6 months
change from baseline with the WASCA system at 6 months
complication
Time Frame: intraoperative and postoperative at 6 months
intraoperative and postoperative at 6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Tianjin Eye Hospital

Collaborators

Alexandria University
Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University
Nethradhama Superspeciality Eye Hospital
Belgian Ocular Laser Centre
Jinan Mingshui Eye Hospital

Investigators

  • Study Director: Yan Wang, director, TianJin eye hospital
  • Principal Investigator: Sri Ganesh, professor, Nethradhama Superspeciality Eye Hospital
  • Principal Investigator: Bernard Heintz, professor, Belgian Ocular Laser Centre
  • Principal Investigator: Osama Ibrahim, professor, Cornea Center, Alexandria University
  • Principal Investigator: Keming Yu, professor, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University
  • Principal Investigator: Yulin Lei, professor, Jinan Mingshui Eye Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2016

Primary Completion (Anticipated)

September 1, 2019

Study Completion (Anticipated)

December 1, 2019

Study Registration Dates

First Submitted

July 12, 2016

First Submitted That Met QC Criteria

July 25, 2016

First Posted (Estimate)

July 26, 2016

Study Record Updates

Last Update Posted (Actual)

May 4, 2018

Last Update Submitted That Met QC Criteria

May 3, 2018

Last Verified

May 1, 2018

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Tianjin EH-SMILE

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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