An observational study in Myopia, sponsored by yuhao shao. Completed at 1 site in China. Open to participants aged 18 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-10-22.
Sponsored by yuhao shao · Observational
To evaluate the subjective and objective postoperative visual quality employing pattern visual evoked potential (P-VEP) following small incision lenticule extraction (SMILE).
1,007 studies on the registry are indexed under Myopia; 210 are open to participants now.
This study's enrollment of 84 is below the median of 150 across 176 observational studies indexed under Myopia.
Browse Myopia studies →yuhao shao is the lead sponsor of 5 studies on the registry; none are open to participants now.
Counted across the registry records on this site, refreshed daily.
hey were divided into three age groups: the \< 26 years group, the 26-35 years group, and the > 35 years group. All participants underwent SMILE surgery performed by an experienced surgeon and received follow-up at 1 week, 1 month, 3 months, and 6 months after SMILE.
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Exclusion Criteria:
patients were enrolled in this study and stratified into three age groups by age
Procedure: small incision lenticule extraction (SMILE)
patients who under small incision lenticule extraction (SMILE) were enrolled in this study and stratified into three age groups by age
Procedure: small incision lenticule extraction (SMILE)
patients who under small incision lenticule extraction (SMILE) were enrolled in this study and stratified into three age groups by age
Procedure: small incision lenticule extraction (SMILE)
The SMILE procedure was conducted by a proficient surgeon utilizing the VisuMax 500 femtosecond laser (Carl Zeiss Meditec AG, Jena, Germany). The thickness of the cap was set to range from 110 to 120 μm, with a diameter of 7.5 mm, and the width of the incision was 2.00 mm. The optical zone was between 6.3 and 6.8 mm. All the patients had successful operations with no complications.
Ocular aberration measurements
Data collection involved consecutive corneal topography assessments using the Orbscan II device (Bausch \& Lomb). Subsequently, ocular aberration evaluations were conducted with a Hartmann-Shack aberrometer (Zywave, Bausch \& Lomb). The ocular aberration data analysis, including high order aberration (HOA), spherical aberration (SA), and coma, was based on a pupil diameter of 6mm.
Time frame: Before the operation, 1 week after the operation, 1 month after the operation, 3 months after the operation, 6 months after the operation
Contrast sensitivity evaluations
CS assessments were performed employing the CSV-1000E (Vector Vision Co., Greenville, Ohio, USA) both prior to surgery and at 1 week, 1 month, 3 months, and 6 months post-surgery. Evaluations were conducted under photopic and mesopic conditions across spatial frequencies of 3, 6, 12, and 18 cycles per degree (cpd).
Time frame: Before the operation, 1 week after the operation, 1 month after the operation, 3 months after the operation, 6 months after the operation
Visual evoked potential measurements
The Pattern Visual Evoked Potential (P-VEP) test was conducted using the ROLAND visual electrodiagnostic test system (Germany). Testing took place in a dark, soundproof room where patients were seated comfortably one meter away from the screen. Patients were encouraged to relax and concentrate on the central fixation light throughout the examination. Pattern-reversal VEP acquisition followed International Society for Clinical Electrophysiology of Vision (ISCEV) recommendations7. The VEP was elicited using two check sizes (1° and 15'). N75 peak time, P100 peak time, and P100 amplitude were measured by 3 technicians, and the final value was the average of the 3 measurements.
Time frame: Before the operation, 1 week after the operation, 1 month after the operation, 3 months after the operation, 6 months after the operation
Quality of vision questionnaires
The Quality of Vision (QoV) Questionnaire was translated into Chinese and completed by patients prior to surgery, as well as 1 week, 1 month, 3 months, and 6 months post-surgery.
Time frame: Before the operation, 1 week after the operation, 1 month after the operation, 3 months after the operation, 6 months after the operation
Plan to share: Undecided
No publications or documents are linked to this record.
Ran from Oct 2021 to primary completion in May 2024, 31 months.
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 31 months is close to 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 completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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