Comparing SMILE and SMILE Xtra procedures for myopia treatment

A Randomized Controlled Trial Comparing Clinical Effectiveness of SMILE Versus SMILE Xtra in Myopia

NA · Shanghai Zhongshan Hospital · NCT06992011

This study is testing which of two eye surgeries, SMILE or SMILE Xtra, works better for treating nearsightedness and keeping your vision stable.

Quick facts

PhaseNA
Study typeInterventional
Enrollment300 (estimated)
Ages18 Years to 50 Years
SexAll
SponsorShanghai Zhongshan Hospital (other)
Locations1 site (Shanghai, Shanghai Municipality)
Trial IDNCT06992011 on ClinicalTrials.gov

What this trial studies

This clinical trial evaluates the effectiveness of two surgical procedures, SMILE and SMILE Xtra, in treating myopia. It aims to compare their clinical efficacy, biomechanical stability, and optical quality through a randomized controlled approach. Participants will be monitored for visual outcomes and any potential complications associated with each procedure.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18-50 with moderate myopia and stable vision over the past two years.

Not a fit: Patients with other eye diseases or those who have had prior ocular surgeries may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide patients with improved options for myopia correction with potentially better visual outcomes.

How similar studies have performed: Previous studies have shown promising results with SMILE procedures, indicating potential for success in this comparative approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Age 18-50 years
2. MRSE (Manifest Refraction Spherical Equivalent) -6.00D to -10.00D with refractive changes within ±0.50D in past 2 years
3. CDVA (Corrected Distance Visual Acuity) ≥ 20/25
4. Myopia progression ≤ 0.50D/year for ≥2 years
5. RST (Residual Stromal Thickness) ≥ 250μm after lenticule removal
6. Contact lens discontinuation as per protocol

Exclusion Criteria:

1. Other eye diseases (keratoconus, glaucoma, etc.)
2. Corneal scarring, cataracts affecting observation
3. Systemic diseases affecting surgery compliance
4. Prior ocular surgeries
5. Pregnancy, breastfeeding, or menstruation
6. Drug allergies to surgical medication

Where this trial is running

Shanghai, Shanghai Municipality

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Myopia

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.