Does intraoperative kappa-angle compensation improve vision after SMILE for small kappa offsets?

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a single-center, randomized, parallel-group study comparing SMILE procedures performed with intraoperative kappa-angle compensation to SMILE without compensation in patients who have small preoperative kappa-angle offsets. Participants will undergo SMILE on the VisuMax 800 platform and will have follow-up visits at 1 week, 1 month, 3 months, and 6 months with measurements of visual quality and refractive outcomes. The primary question is whether compensation reduces higher-order aberrations and improves postoperative visual performance compared with no compensation. The study aims to determine if precise intraoperative centration based on the kappa-angle can enhance optical quality after refractive surgery.

Why it matters

Who can join: the full rules

Inclusion Criteria:

1. Patients aged 18 to 40 years with myopia or myopic astigmatism and stable refraction for \>=1 year, whose refractive errors fall within the treatable range of and meet the indications for SMILE surgery.
2. Normal corneal morphology and corneal thickness meeting surgical requirements.
3. Preoperative corrected distance visual acuity (CDVA) \>= 1.0.
4. Preoperative synthetic Kappa angle offset measured \>= 0.10 mm and \< 0.20 mm.
5. Voluntarily agree to undergo SMILE surgery on the VISUMAX 800 platform, understand the randomization scheme, and provide signed informed consent.

Exclusion Criteria:

1. History of prior ocular surgery, significant ocular trauma, or presence of corneal or ocular diseases that may affect the safety of refractive surgery.
2. Severe systemic diseases that may affect ocular healing or surgical safety.
3. Females who are pregnant or lactating.
4. Inability to cooperate as required to complete the procedure or follow-up visits.

Where it's running

• Zhongshan Ophthalmic Center
  Guangzhou, Guangdong, China Recruiting

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Low vs high kappa-angle compensation during SMILE with VisuMax 800

  This trial tests whether using a low (50%) or high (100%) kappa-angle compensation during SMILE surgery with the VisuMax 800 produces better postoperative vision for adults with myopia and large kappa offsets.

  Recruiting Zhongshan Ophthalmic Center, Sun Yat-sen University · Guangzhou, Guangdong · NCT07512102

• Evaluating a device for screening vision problems in young children

  This study is testing a new device to see if it can effectively find vision problems in children aged 3 to 8, whether they wear glasses or not.

  Recruiting Essilor International · Nancy, France and 1 other locations · NCT06882408

• Optimizing light exposure to prevent and control myopia in children

  This study tests if changing classroom lighting to mimic sunlight or using a smartphone app to guide light exposure can help prevent and control myopia in primary school children.

  Recruiting at 5 sites National University of Singapore · Singapore and 4 other locations · NCT06631339

• Hyperopic reserve screening for kindergartners in Beijing

  A population-wide screening tests whether senior kindergarten children in Beijing have enough hyperopic reserve to help prevent future myopia.

  Recruiting Beijing Tongren Hospital · Beijing · NCT07851532

• Do dual-focus multifocal contact lenses improve hand-eye coordination and sports vision compared with your usual lenses

  This study tests whether wearing dual-focus multifocal contact lenses improves hand-eye coordination and sports vision in adults who play baseball or softball and normally wear contact lenses.

  Recruiting Ohio State University · Columbus, Ohio · NCT07840209

• Two monthly silicone hydrogel multifocal toric contact lenses in wearers with astigmatism and myopia

  This study tests whether two popular soft multifocal toric contact lenses perform differently in adults who need vision correction for astigmatism and myopia.

  Recruiting CooperVision International Limited (CVIL) · New York, New York and 2 other locations · NCT07829419

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.