MyopiaNCT06992011
A Randomized Controlled Trial Comparing Clinical Effectiveness of SMILE Versus SMILE Xtra in Myopia
A study testing SMILE and SMILE Xtra in people with Myopia, run by Shanghai Zhongshan Hospital at 1 site in China.
Trial summary
To evaluate and compare the clinical efficacy, biomechanical stability, and optical quality of SMILE and SMILE Xtra procedures in patients with myopia through a randomized controlled trial Read more about this study
- Who is it for?
- Ages 18 to 50 years
- Conditions the study is for
- Myopia
- What is being tested?
- SMILE and SMILE Xtra
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 300 participants
- Where
- 1 siteChina
- Study dates
- 1 Feb 2023to Feb 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Age 18-50 years
- MRSE (Manifest Refraction Spherical Equivalent) -6.00D to -10.00D with refractive changes within ±0.50D in past 2 years
- CDVA (Corrected Distance Visual Acuity) ≥ 20/25
- Myopia progression ≤ 0.50D/year for ≥2 years
- RST (Residual Stromal Thickness) ≥ 250μm after lenticule removal
- Contact lens discontinuation as per protocol
Who cannot join
- Other eye diseases (keratoconus, glaucoma, etc.)
- Corneal scarring, cataracts affecting observation
- Systemic diseases affecting surgery compliance
- Prior ocular surgeries
- Pregnancy, breastfeeding, or menstruation
- Drug allergies to surgical medication
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Zhongshan Hospital
Shanghai, Shanghai Municipality, 200032
Cong Jing, 17269769976, lucky_congjing@163.com
About this study
To evaluate and compare the clinical efficacy, biomechanical stability, and optical quality of SMILE and SMILE Xtra procedures in patients with myopia through a randomized controlled trial
- Conditions
- Myopia
- Being tested
- SMILE, SMILE Xtra
- Medical subject headings
- Myopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SMILEProcedure or surgery
Small Incision Lenticule Extraction
SMILE XtraProcedure or surgery
Small Incision Lenticule Extraction combined with Corneal Cross-linking (SMILE Xtra)
| Study group | Role | What they receive |
|---|---|---|
| SMILE Group | Active comparator | Not described Receives: Procedure: SMILE |
| SMILE Xtra Group | Experimental | Not described Receives: Procedure: SMILE Xtra |
What is being measured
The primary outcome is the main question the study is designed to answer.
visual acuity
Measured: 1 week, 1 month,3 months， 6 months, 12 months, 24 months, and 36 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 May 2025
- Study start1 Feb 2023
- Primary completionFeb 2027 (estimated)
- Study completionFeb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for MyopiaStudies of the same condition, open and under way.
- More trials run by Shanghai Zhongshan HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Shanghai Zhongshan Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06992011
- Sponsor's protocol ID
- B2024-267R-1
- Status last verified
- May 2025
- First submitted
- 19 May 2025
- Last updated
- 28 May 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Cong J, Lin X, Yuan J, Li X, Liu W, Mao X, Zheng C, Liu S, Feng Q, Dong C, Feng C, Yuan Y, Dai J. Comparing Efficacy and Corneal Biomechanics Between KLEx and KLEx Xtra in High Myopia: A 1-Year Prospective Randomized Study. Ophthalmol Ther. 2026 Apr;15(4):1355-1374. doi: 10.1007/s40123-026-01340-1. Epub 2026 Mar 4.
PubMed 41781518
Study at a glance
From the registry record, last updated by the sponsor on 28 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized Controlled Trial Comparing Clinical Effectiveness of SMILE Versus SMILE Xtra in Myopia
- ClinicalTrials.gov ID
- NCT06992011
- Acronym / sponsor ID
- B2024-267R-1
- Conditions
- Myopia
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- Shanghai Zhongshan HospitalUniversity, hospital or other
- Study start
- 1 Feb 2023 (actual)
- Primary completion
- Feb 2027 (estimated)
- Study completion
- Feb 2027 (estimated)
- First posted
- 28 May 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
To evaluate and compare the clinical efficacy, biomechanical stability, and optical quality of SMILE and SMILE Xtra procedures in patients with myopia through a randomized controlled trial
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| SMILE Group | Active comparator | Procedure: SMILE |
| SMILE Xtra Group | Experimental | Procedure: SMILE Xtra |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Age 18-50 years
- MRSE (Manifest Refraction Spherical Equivalent) -6.00D to -10.00D with refractive changes within ±0.50D in past 2 years
- CDVA (Corrected Distance Visual Acuity) ≥ 20/25
- Myopia progression ≤ 0.50D/year for ≥2 years
- RST (Residual Stromal Thickness) ≥ 250μm after lenticule removal
Key exclusion criteria (6 listed)
- Other eye diseases (keratoconus, glaucoma, etc.)
- Corneal scarring, cataracts affecting observation
- Systemic diseases affecting surgery compliance
- Prior ocular surgeries
- Pregnancy, breastfeeding, or menstruation
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SMILESmall Incision Lenticule Extraction | Procedure or surgery | SMILE Group |
| SMILE XtraSmall Incision Lenticule Extraction combined with Corneal Cross-linking (SMILE Xtra) | Procedure or surgery | SMILE Xtra Group |
Primary outcome
visual acuity
Time frame: 1 week, 1 month,3 months， 6 months, 12 months, 24 months, and 36 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 May 2025.
- Derived from this study: PubMed 41781518Cong J, Lin X, Yuan J, Li X, Liu W, Mao X, Zheng C, Liu S, Feng Q, Dong C, Feng C, Yuan Y, Dai J. Comparing Efficacy and Corneal Biomechanics Between KLEx and KLEx Xtra in High Myopia: A 1-Year Prospective Randomized Study. Ophthalmol Ther. 2026 Apr;15(4):1355-1374. doi: 10.1007/s40123-026-01340-1. Epub 2026 Mar 4.
Related trials for Myopia
Recruiting
Evaluation of Two Monthly Silicone Hydrogel Multifocal Toric in Soft Contact Lens Wearers
Astigmatism, Myopia
Active, not recruiting
Correcting Myopia Among Secondary School Children to Increase Academic High School Attendance Rates in Rural Communities
Refractive Errors
Not yet recruitingObservational study
Corneal Biomechanics and Stromal Tissue Characteristics in Patients Undergoing SMILE
Myopia
Not yet recruiting
The EYERISING Study
Myopia, Astigmatism
Recruiting
Children's Viewing Behavior
Myopia, Myopia Progression
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing SMILE and SMILE Xtra in people with Myopia, run by Shanghai Zhongshan Hospital at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 28 May 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Cong Jing (17269769976, lucky_congjing@163.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
visual acuity (time frame: 1 week, 1 month,3 months， 6 months, 12 months, 24 months, and 36 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06992011, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 May 2025.