An observational study in Myopia, sponsored by Tongji University. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by Tongji University · Observational
This prospective observational cohort study will investigate corneal biomechanical characteristics and their relationships with corneal stromal tissue features in adult patients undergoing clinically indicated small-incision lenticule extraction (SMILE).
Participants will undergo standardized preoperative examinations, including Corvis ST assessment, refraction, axial length measurement, and corneal imaging. Corneal lenticules removed during routine SMILE surgery will be collected with informed consent and linked to clinical measurements from the corresponding eye using coded identifiers.
The primary objective is to compare preoperative stiffness parameter at first applanation (SP-A1) between patients with high myopia and those with non-high myopia. Secondary objectives are to characterize postoperative biomechanical changes and clinical outcomes during 12 months of follow-up. Exploratory analyses will investigate relationships between stromal tissue characteristics and clinical biomechanical measurements.
Surgical eligibility, surgical parameters, and postoperative care will be determined according to routine clinical practice independently of study participation. No additional corneal tissue will be removed for research.
Eligible adult patients scheduled for SMILE at [institution] will be consecutively screened and invited to participate after ethics approval and public study registration have been completed. Written informed consent will be obtained before study-specific procedures.
Baseline examinations will be performed before surgery and will include medical and ocular history, visual acuity, manifest refraction, axial length, intraocular pressure, corneal thickness and tomography, and Corvis ST measurements. Acquisition conditions, measurement quality, and device software versions will be recorded according to a standardized examination procedure.
One primary study eye will be selected before surgery. If both eyes are eligible, the primary study eye will be selected using a computer-generated random procedure before tissue results are available. Measurements and specimens from the fellow eye may be retained for separately identified exploratory analyses.
Participants will be classified according to the preoperative manifest refractive spherical equivalent of the primary study eye. High myopia will be defined as a spherical equivalent of -6.00 diopters or more myopic. Non-high myopia will be defined as a spherical equivalent of -0.50 diopters or more myopic but less myopic than -6.00 diopters.
Corneal lenticules removed during clinically indicated SMILE will be collected using a standardized handling and storage procedure. Each specimen will be linked to participant identifier, eye laterality, surgery date, and relevant surgical parameters. Structural and molecular analyses will investigate stromal remodeling and extracellular matrix characteristics. Specific assays and quantitative readouts will be documented in the protocol or a dated substudy analysis plan before the corresponding analyses.
Postoperative assessments will be scheduled at 1, 3, and 12 months after SMILE. Visual acuity, manifest refraction, intraocular pressure, corneal thickness, and Corvis ST measurements will be collected. Relevant medications, complications, and additional ocular procedures will be documented.
The primary analysis will compare baseline SP-A1 between the two refractive groups. Prespecified covariates will include age, sex, central corneal thickness, and intraocular pressure. Axial length will be examined as a continuous exposure in a separate supporting analysis.
Longitudinal models will account for repeated measurements. Analyses incorporating fellow eyes will additionally account for within-participant correlation. Estimates will be reported with 95% confidence intervals. Missing measurements, unavailable specimens, and reasons for loss to follow-up will be documented. Tissue analyses will use the corresponding-eye clinical measurements and will distinguish individual specimens from pooled samples.
Additional analyses of coded data or retained specimens will remain subject to participant consent and ethics approval. New confirmatory hypotheses will require dated analysis plans. Any exploratory prediction models will be evaluated offline and will not determine patient treatment.
1,010 studies on the registry are indexed under Myopia; 212 are open to participants now.
This study's planned enrollment of 200 is above the median of 150 across 177 observational studies indexed under Myopia.
Browse Myopia studies →Tongji University is the lead sponsor of 40 studies on the registry; 12 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Adult patients attending the refractive surgery service at [institution, city, China] who are scheduled for clinically indicated SMILE will be screened. All patients meeting the eligibility criteria during the recruitment period will be invited to participate. The study population represents patients selected for SMILE and is not intended to represent all individuals with myopia.
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Exclusion Criteria:
Patients undergoing clinically indicated SMILE whose primary study eye has a preoperative manifest refractive spherical equivalent of -6.00 diopters or more myopic.
Procedure: SMILE
Patients undergoing clinically indicated SMILE whose primary study eye has a preoperative manifest refractive spherical equivalent of -0.50 diopters or more myopic but less myopic than -6.00 diopters.
Procedure: SMILE
Clinically indicated SMILE performed according to routine clinical practice. Surgical selection and treatment parameters are not assigned by the research protocol. Removed lenticules will be retained with informed consent.
Preoperative Stiffness Parameter at First Applanation (SP-A1)
SP-A1 will be obtained from quality-accepted Corvis ST measurements of the primary study eye. The acquisition and repeat-measurement rules will be standardized before enrollment. The primary comparison will estimate the difference in baseline SP-A1 between the high-myopia and non-high-myopia groups.
Time frame: Baseline, 1year
Preoperative Integrated Inverse Radius
Integrated inverse radius will be obtained from quality-accepted Corvis ST measurements of the primary study eye and compared between the prespecified refractive groups.
Time frame: Baseline, 1year
Change in SP-A1 From Baseline to 12 Months
Change will be calculated as SP-A1 at 12 months after SMILE minus preoperative SP-A1 in the primary study eye. Associations with baseline clinical characteristics and surgical parameters will be examined using prespecified analyses.
Time frame: Baseline, 1year
Manifest Refractive Spherical Equivalent at 12 Months
Manifest refractive spherical equivalent will be calculated as sphere plus one-half of cylinder, expressed in diopters, for the primary study eye.
Time frame: 1year
Early Postoperative Changes in SP-A1
Changes from preoperative SP-A1 will be calculated separately at 1 and 3 months after SMILE to characterize the early postoperative trajectory.
Time frame: 1 and 3 months
Other open studies at Shanghai Tenth People's Hospital, Shanghai
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Plan to share: Undecided — A decision regarding sharing of de-identified individual participant data will be made in accordance with participant consent, institutional policies, ethics approval, and applicable requirements. Any future sharing plan will specify the eligible datasets, access conditions, and supporting documentation.
No publications or documents are linked to this record.
Start is estimated for Oct 2026; primary completion for Jun 2027, 8 months later.
Of 71 non-industry observational studies under Myopia, half reached primary completion within 29 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 92. This study's planned 8 months is below that.
Counting every sponsor, half of 79 studies reached it within 26 months; a quarter within 12 and three quarters within 90.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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Tongji University