MyopiaNCT07696468
Comparison of Two Rotational Alignment Methods for Astigmatism Correction in SMILE Surgery
A study testing Manual limbal marking-guided cyclotorsion adjustment during SMILE in people with Myopia and Refractive Ametropia, run by Zhongshan Ophthalmic Center, Sun Yat-sen University at 1 site in China.
Trial summary
Small incision lenticule extraction (SMILE) is a commonly used corneal refractive procedure for correcting myopia and myopic astigmatism. During astigmatism correction, eye rotation between the upright examination position and the supine surgical position may affect the alignment of the astigmatic treatment axis and… Read more about this study
- Who is it for?
- Ages 18 to 40 years
- Conditions the study is for
- Myopia, Refractive Ametropia
- What is being tested?
- Manual limbal marking-guided cyclotorsion adjustment during SMILE
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 52 participants
- Where
- 1 siteChina
- Study dates
- 13 Jul 2026to 30 Jun 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 40 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Age range: 18 - 40 years old. Patients with myopic astigmatism and stable refractive status for >= 1 year.
- Normal corneal morphology in both eyes, with corneal thickness and other ocular parameters meeting the requirements for SMILE surgery.
- Preoperative corrected distance visual acuity (CDVA) >= 1.0 in both eyes.
- Manifest refractive cylinder >= 0.75 D in both eyes, with an interocular difference in absolute cylinder power <= 1.00 D.
- Both eyes can provide reliable preoperative upright-position image information required for astigmatic axis recognition, and are judged by the investigator to meet the requirements for OcuLign cyclotorsion recognition and axis alignment on the VISUMAX 800 platform.
- Voluntary to undergo bilateral SMILE surgery on the VISUMAX 800 platform, understanding the random eye-assignment scheme and signing the informed consent form.
Who cannot join
- History of prior ocular surgery, significant ocular trauma, or presence of ocular diseases that may affect the safety of refractive surgery or the interpretation of study outcomes.
- Irregular astigmatism or poor repeatability of bilateral astigmatism measurements, making reliable astigmatic axis analysis impossible.
- Presence of strabismus, nystagmus, significant binocular vision abnormality, or any condition that may affect fixation or cooperation during examinations.
- Severe systemic diseases that may affect ocular healing or surgical safety.
- Females who are pregnant or lactating.
- Inability to complete the required postoperative follow-up visits or questionnaire assessments.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Comparison of Astigmatic Correction Outcomes Following SMILE With OcuLign-Assisted Cyclotorsion Control and Manual Limbal Marking: A Prospective Randomized Contralateral-Eye Noninferiority Study
Small incision lenticule extraction (SMILE) is a commonly used corneal refractive procedure for correcting myopia and myopic astigmatism. During astigmatism correction, eye rotation between the upright examination position and the supine surgical position may affect the alignment of the astigmatic treatment axis and may contribute to residual astigmatism after surgery.
Manual limbal marking is a commonly used method to guide cyclotorsion adjustment during refractive surgery. OcuLign is an assisted cyclotorsion control function of the VISUMAX 800 platform that helps identify ocular rotation and guide axis alignment during SMILE. However, direct clinical evidence comparing OcuLign-assisted cyclotorsion control with manual limbal marking during SMILE is limited.
Read more
This study is a single-center, prospective, randomized, masked, contralateral-eye non-inferiority trial. Adults aged 18 to 40 years with stable myopia and astigmatism who plan to undergo bilateral SMILE surgery will be enrolled. In each participant, one eye will receive SMILE with OcuLign-assisted cyclotorsion control, and the fellow eye will receive SMILE with manual limbal marking-guided cyclotorsion adjustment. The treatment assigned to the right eye will be determined by randomization.
The primary objective is to compare residual refractive astigmatism at 3 months after surgery between the two methods. Secondary outcomes include visual acuity, refractive predictability and stability, astigmatism vector analysis, higher-order aberrations, contrast sensitivity, patient-reported quality of vision, overall satisfaction, and safety outcomes. Participants will be followed for approximately 6 months after surgery.
Read the detailed description
Accurate alignment of the astigmatic treatment axis is an important factor in the correction of myopic astigmatism during small incision lenticule extraction (SMILE). Cyclotorsion may occur when a patient changes from the upright preoperative examination position to the supine surgical position, and may also be influenced by fixation, head position, and suction during surgery. Inadequate compensation for ocular rotation may reduce astigmatic correction accuracy and contribute to postoperative residual astigmatism.
Manual limbal marking is a commonly used method for cyclotorsion adjustment in corneal refractive surgery. This method is clinically feasible and widely used, but it depends on preoperative marking and intraoperative manual judgment. Marking clarity, ocular surface conditions, patient cooperation, and surgeon experience may affect the accuracy and reproducibility of the adjustment. OcuLign is an assisted cyclotorsion control function of the VISUMAX 800 platform that helps identify ocular rotation and guide axis alignment during SMILE. This study is designed to compare OcuLign-assisted cyclotorsion control with manual limbal marking-guided cyclotorsion adjustment during SMILE.
This trial uses a prospective, randomized, contralateral-eye non-inferiority design. Each participant will undergo bilateral SMILE surgery. One eye will be assigned to OcuLign-assisted cyclotorsion control, and the fellow eye will be assigned to manual limbal marking-guided cyclotorsion adjustment, according to a prespecified randomization sequence. This paired-eye design is intended to reduce inter-individual variability in refractive characteristics, healing response, and subjective visual perception. Apart from the method of cyclotorsion adjustment, surgical parameters, lenticule design, suction procedure, postoperative medication, and follow-up schedule will be kept consistent between the two eyes.
Participants and postoperative outcome assessors will be masked to the eye-level treatment assignment whenever feasible. The operating surgeon cannot be masked because the assigned cyclotorsion adjustment method must be performed during surgery. Postoperative assessments will be conducted at predefined follow-up visits through approximately 6 months after surgery.
The primary comparison will evaluate whether OcuLign-assisted cyclotorsion control is non-inferior to manual limbal marking-guided adjustment in terms of residual refractive astigmatism at 3 months after surgery. Secondary assessments will evaluate visual acuity, refractive predictability and stability, astigmatism vector parameters, higher-order aberrations, contrast sensitivity, patient-reported quality of vision, satisfaction, and safety. Safety monitoring will include loss of corrected distance visual acuity and postoperative adverse events.
- Conditions
- Myopia, Refractive Ametropia
- Being tested
- Device-assisted cyclotorsion control during SMILE, Manual limbal marking-guided cyclotorsion adjustment during SMILE
- Keywords
- myopia, SMILE, VisuMax 800, Cyclotorsion
- Medical subject headings
- Myopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Device-assisted cyclotorsion control during SMILEProcedure or surgery
Also called OcuLign-assisted cyclotorsion control, VISUMAX 800 OcuLign
One eye of each participant will undergo SMILE using device-assisted cyclotorsion control with the OcuLign function of the VISUMAX 800 platform. During surgery, OcuLign will assist in identifying ocular rotation and guiding astigmatic axis alignment. Apart from the cyclotorsion adjustment method, the surgical parameters, lenticule design, suction procedure, postoperative medication, and follow-up schedule will be the same as those used for the fellow eye.
Manual limbal marking-guided cyclotorsion adjustment during SMILEProcedure or surgery
The fellow eye of each participant will undergo SMILE using manual limbal marking-guided cyclotorsion adjustment. Limbal reference marks will be made in the upright preoperative position, and intraoperative axis alignment will be manually adjusted according to the limbal marks and the surgical reference direction. Apart from the cyclotorsion adjustment method, the surgical parameters, surgical procedure, postoperative medication, and follow-up schedule will be the same as those used for the contralateral eye.
| Study group | Role | What they receive |
|---|---|---|
| OcuLign-Assisted Cyclotorsion Control | Experimental | One eye of each participant will undergo SMILE using OcuLign-assisted cyclotorsion control on the VISUMAX 800 platform. OcuLign will be used intraoperatively to assist in identifying ocular rotation and guiding astigmatic axis alignment. Apart from the cyclotorsion adjustment method, the surgical parameters, lenticule design, suction procedure, postoperative medication, and follow-up schedule will be the same as those used for the fellow eye. Receives: Procedure: Device-assisted cyclotorsion control during SMILE |
| Manual Limbal Marking-Guided Adjustment | Active comparator | The fellow eye of each participant will undergo SMILE using manual limbal marking-guided cyclotorsion adjustment. Limbal reference marks will be made in the upright preoperative position, and intraoperative axis alignment will be manually adjusted according to the marks and the surgical reference direction. Apart from the cyclotorsion adjustment method, the surgical parameters, surgical procedure, postoperative medication, and follow-up schedule will be the same as those used for the contralateral eye. Receives: Procedure: Manual limbal marking-guided cyclotorsion adjustment during SMILE |
What is being measured
The primary outcome is the main question the study is designed to answer.
Residual refractive astigmatism
Residual refractive astigmatism will be measured as the absolute manifest cylinder power in diopters at 3 months after SMILE. The primary analysis will compare residual refractive astigmatism between eyes treated with OcuLign-assisted cyclotorsion control and eyes treated with manual limbal marking-guided cyclotorsion adjustment to evaluate non-inferiority.
Measured: 3 months after surgery
Secondary outcomes (10)
Astigmatic correction predictability
Astigmatic correction predictability will be assessed as the proportion of eyes with postoperative residual manifest cylinder within predefined thresholds, including ≤0.25 D, ≤0.50 D, and ≤1.00 D.
Measured: 1 month, 3 months, and 6 months after surgery
Astigmatic Correction Assessed by Alpins Vector Analysis
Postoperative astigmatic correction will be assessed using the Alpins vector analysis method based on refractive cylinder and axis data. This outcome will be used to describe the overall accuracy of astigmatism correction after surgery.
Measured: 3 months after surgery
Visual acuity
Uncorrected distance visual acuity and corrected distance visual acuity will be measured using standardized visual acuity charts and recorded as logMAR visual acuity. Visual acuity-derived performance will also be summarized using the safety index and efficacy index, calculated from the same visual acuity measurements. The safety index is defined as postoperative corrected distance visual acuity divided by preoperative corrected distance visual acuity, and the efficacy index is defined as postoperative uncorrected distance visual acuity divided by preoperative corrected distance visual acuity.
Measured: 1 month, 3 months, and 6 months after surgery
Manifest refraction
Postoperative manifest refraction will include sphere, cylinder, and spherical equivalent measured by standard manifest refraction.
Measured: 1 month, 3 months, and 6 months after surgery
Refractive accuracy
Refractive accuracy will be assessed as the proportion of eyes with postoperative spherical equivalent within predefined ranges of the target refraction, including within ±0.25 D, ±0.50 D, and ±1.00 D.
Measured: 1 month, 3 months, and 6 months after surgery
Refractive stability
Refractive stability will be assessed as the change in manifest spherical equivalent refraction between postoperative follow-up visits.
Measured: 1 month to 6 months after surgery
Higher-Order Wavefront Aberration Assessment
Higher-order wavefront aberrations will be measured using wavefront aberrometry under standardized conditions to assess postoperative optical quality.
Measured: 1 month, 3 months, and 6 months after surgery
Contrast sensitivity
Contrast sensitivity will be measured under standardized conditions using the CSV-1000 contrast sensitivity testing system at multiple spatial frequencies, including 3, 6, 12, and 18 cycles per degree. The area under the log contrast sensitivity function may be calculated as a summary measure when appropriate.
Measured: 3 months after surgery
Quality of Vision score
Subjective visual symptoms will be assessed using the Quality of Vision questionnaire, which evaluates the frequency, severity, and bothersome nature of visual disturbances such as glare, halos, and double vision. Higher scores indicate worse subjective visual quality.
Measured: 3 months after surgery
Overall visual satisfaction score
Overall visual satisfaction will be assessed using a 5-point Likert rating scale. Scores range from 1 to 5, with higher scores indicating greater satisfaction.
Measured: 3 months after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jul 2026
- Study start13 Jul 2026 (estimated)
- Primary completion30 Jun 2027 (estimated)
- Study completion30 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for MyopiaStudies of the same condition, open and under way.
- 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
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 52 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Zhongshan Ophthalmic Center, Sun Yat-sen University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07696468
- Sponsor's protocol ID
- IIT2026071
- Status last verified
- Jul 2026
- First submitted
- 6 Jul 2026
- Last updated
- 15 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Chen P, Ye Y, Yu N, Zhang X, He J, Zheng H, Wei H, Zhuang J, Yu K. Comparison of Small Incision Lenticule Extraction Surgery With and Without Cyclotorsion Error Correction for Patients With Astigmatism. Cornea. 2019 Jun;38(6):723-729. doi: 10.1097/ICO.0000000000001937.
PubMed 30950894Wang B, Wang Y, Zhang J. Comparison of astigmatic correction with and without limbal marking during small-incision lenticule extraction. J Cataract Refract Surg. 2022 Aug 1;48(8):924-928. doi: 10.1097/j.jcrs.0000000000000889.
PubMed 35067664Yang X, Liu Y, Xiao K, Song Q, Xu Y, Li J, Zhou Y. Effect of Cyclotorsion Compensation in Small Incision Lenticule Extraction Surgery for the Correction of Myopic Astigmatism: A Systematic Review and Meta-Analysis. Ophthalmol Ther. 2024 May;13(5):1271-1288. doi: 10.1007/s40123-024-00921-2. Epub 2024 Mar 18.
PubMed 38498276
Study at a glance
From the registry record, last updated by the sponsor on 15 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Astigmatic Correction Outcomes Following SMILE With OcuLign-Assisted Cyclotorsion Control and Manual Limbal Marking: A Prospective Randomized Contralateral-Eye Noninferiority Study
- ClinicalTrials.gov ID
- NCT07696468
- Acronym / sponsor ID
- IIT2026071
- Conditions
- Myopia, Refractive Ametropia
- Keywords
- myopia, SMILE, VisuMax 800, Cyclotorsion
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 52 participants (estimated)
- Lead sponsor
- Zhongshan Ophthalmic Center, Sun Yat-sen UniversityUniversity, hospital or other
- Study start
- 13 Jul 2026 (estimated)
- Primary completion
- 30 Jun 2027 (estimated)
- Study completion
- 30 Jun 2027 (estimated)
- First posted
- 10 Jul 2026 (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.
Small incision lenticule extraction (SMILE) is a commonly used corneal refractive procedure for correcting myopia and myopic astigmatism. During astigmatism correction, eye rotation between the upright examination position and the supine surgical position may affect the alignment of the astigmatic treatment axis and may contribute to residual astigmatism after surgery.
Manual limbal marking is a commonly used method to guide cyclotorsion adjustment during refractive surgery. OcuLign is an assisted cyclotorsion control function of the VISUMAX 800 platform that helps identify ocular rotation and guide axis alignment during SMILE. However, direct clinical evidence comparing OcuLign-assisted cyclotorsion control with manual limbal marking during SMILE is limited.
This study is a single-center, prospective, randomized, masked, contralateral-eye non-inferiority trial. Adults aged 18 to 40 years with stable myopia and astigmatism who plan to undergo bilateral SMILE surgery will be enrolled. In each participant, one eye will receive SMILE with OcuLign-assisted cyclotorsion control, and the fellow eye will receive SMILE with manual limbal marking-guided cyclotorsion adjustment. The treatment assigned to the right eye will be determined by randomization.
The primary objective is to compare residual refractive astigmatism at 3 months after surgery between the two methods. Secondary outcomes include visual acuity, refractive predictability and stability, astigmatism vector analysis, higher-order aberrations, contrast sensitivity, patient-reported quality of vision, overall satisfaction, and safety outcomes. Participants will be followed for approximately 6 months after surgery.
Detailed description
Accurate alignment of the astigmatic treatment axis is an important factor in the correction of myopic astigmatism during small incision lenticule extraction (SMILE). Cyclotorsion may occur when a patient changes from the upright preoperative examination position to the supine surgical position, and may also be influenced by fixation, head position, and suction during surgery. Inadequate compensation for ocular rotation may reduce astigmatic correction accuracy and contribute to postoperative residual astigmatism.
Manual limbal marking is a commonly used method for cyclotorsion adjustment in corneal refractive surgery. This method is clinically feasible and widely used, but it depends on preoperative marking and intraoperative manual judgment. Marking clarity, ocular surface conditions, patient cooperation, and surgeon experience may affect the accuracy and reproducibility of the adjustment. OcuLign is an assisted cyclotorsion control function of the VISUMAX 800 platform that helps identify ocular rotation and guide axis alignment during SMILE. This study is designed to compare OcuLign-assisted cyclotorsion control with manual limbal marking-guided cyclotorsion adjustment during SMILE.
This trial uses a prospective, randomized, contralateral-eye non-inferiority design. Each participant will undergo bilateral SMILE surgery. One eye will be assigned to OcuLign-assisted cyclotorsion control, and the fellow eye will be assigned to manual limbal marking-guided cyclotorsion adjustment, according to a prespecified randomization sequence. This paired-eye design is intended to reduce inter-individual variability in refractive characteristics, healing response, and subjective visual perception. Apart from the method of cyclotorsion adjustment, surgical parameters, lenticule design, suction procedure, postoperative medication, and follow-up schedule will be kept consistent between the two eyes.
Participants and postoperative outcome assessors will be masked to the eye-level treatment assignment whenever feasible. The operating surgeon cannot be masked because the assigned cyclotorsion adjustment method must be performed during surgery. Postoperative assessments will be conducted at predefined follow-up visits through approximately 6 months after surgery.
The primary comparison will evaluate whether OcuLign-assisted cyclotorsion control is non-inferior to manual limbal marking-guided adjustment in terms of residual refractive astigmatism at 3 months after surgery. Secondary assessments will evaluate visual acuity, refractive predictability and stability, astigmatism vector parameters, higher-order aberrations, contrast sensitivity, patient-reported quality of vision, satisfaction, and safety. Safety monitoring will include loss of corrected distance visual acuity and postoperative adverse events.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| OcuLign-Assisted Cyclotorsion Control | Experimental | Procedure: Device-assisted cyclotorsion control during SMILEOne eye of each participant will undergo SMILE using OcuLign-assisted cyclotorsion control on the VISUMAX 800 platform. OcuLign will be used intraoperatively to assist in identifying ocular rotation and guiding astigmatic axis alignment. Apart from the cyclotorsion adjustment method, the surgical parameters, lenticule design, suction procedure, postoperative medication, and follow-up schedule will be the same as those used for the fellow eye. |
| Manual Limbal Marking-Guided Adjustment | Active comparator | Procedure: Manual limbal marking-guided cyclotorsion adjustment during SMILEThe fellow eye of each participant will undergo SMILE using manual limbal marking-guided cyclotorsion adjustment. Limbal reference marks will be made in the upright preoperative position, and intraoperative axis alignment will be manually adjusted according to the marks and the surgical reference direction. Apart from the cyclotorsion adjustment method, the surgical parameters, surgical procedure, postoperative medication, and follow-up schedule will be the same as those used for the contralateral eye. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Age range: 18 - 40 years old. Patients with myopic astigmatism and stable refractive status for >= 1 year.
- Normal corneal morphology in both eyes, with corneal thickness and other ocular parameters meeting the requirements for SMILE surgery.
- Preoperative corrected distance visual acuity (CDVA) >= 1.0 in both eyes.
- Manifest refractive cylinder >= 0.75 D in both eyes, with an interocular difference in absolute cylinder power <= 1.00 D.
- Both eyes can provide reliable preoperative upright-position image information required for astigmatic axis recognition, and are judged by the investigator to meet the requirements for OcuLign cyclotorsion recognition and axis alignment on the VISUMAX 800 platform.
Key exclusion criteria (6 listed)
- History of prior ocular surgery, significant ocular trauma, or presence of ocular diseases that may affect the safety of refractive surgery or the interpretation of study outcomes.
- Irregular astigmatism or poor repeatability of bilateral astigmatism measurements, making reliable astigmatic axis analysis impossible.
- Presence of strabismus, nystagmus, significant binocular vision abnormality, or any condition that may affect fixation or cooperation during examinations.
- Severe systemic diseases that may affect ocular healing or surgical safety.
- Females who are pregnant or lactating.
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 |
|---|---|---|
| Device-assisted cyclotorsion control during SMILEAlso: OcuLign-assisted cyclotorsion control, VISUMAX 800 OcuLignOne eye of each participant will undergo SMILE using device-assisted cyclotorsion control with the OcuLign function of the VISUMAX 800 platform. During surgery, OcuLign will assist in identifying ocular rotation and guiding astigmatic axis alignment. Apart from the cyclotorsion adjustment method, the surgical parameters, lenticule design, suction procedure, postoperative medication, and follow-up schedule will be the same as those used for the fellow eye. | Procedure or surgery | OcuLign-Assisted Cyclotorsion Control |
| Manual limbal marking-guided cyclotorsion adjustment during SMILEThe fellow eye of each participant will undergo SMILE using manual limbal marking-guided cyclotorsion adjustment. Limbal reference marks will be made in the upright preoperative position, and intraoperative axis alignment will be manually adjusted according to the limbal marks and the surgical reference direction. Apart from the cyclotorsion adjustment method, the surgical parameters, surgical procedure, postoperative medication, and follow-up schedule will be the same as those used for the contralateral eye. | Procedure or surgery | Manual Limbal Marking-Guided Adjustment |
Primary outcome
Residual refractive astigmatism
Time frame: 3 months after surgery
Residual refractive astigmatism will be measured as the absolute manifest cylinder power in diopters at 3 months after SMILE. The primary analysis will compare residual refractive astigmatism between eyes treated with OcuLign-assisted cyclotorsion control and eyes treated with manual limbal marking-guided cyclotorsion adjustment to evaluate non-inferiority.
10 secondary outcomes
Astigmatic correction predictability
Time frame: 1 month, 3 months, and 6 months after surgery
Astigmatic Correction Assessed by Alpins Vector Analysis
Time frame: 3 months after surgery
Visual acuity
Time frame: 1 month, 3 months, and 6 months after surgery
Manifest refraction
Time frame: 1 month, 3 months, and 6 months after surgery
Refractive accuracy
Time frame: 1 month, 3 months, and 6 months after surgery
Refractive stability
Time frame: 1 month to 6 months after surgery
Higher-Order Wavefront Aberration Assessment
Time frame: 1 month, 3 months, and 6 months after surgery
Contrast sensitivity
Time frame: 3 months after surgery
Quality of Vision score
Time frame: 3 months after surgery
Overall visual satisfaction score
Time frame: 3 months after surgery
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 15 Jul 2026.
- Background: PubMed 30950894Chen P, Ye Y, Yu N, Zhang X, He J, Zheng H, Wei H, Zhuang J, Yu K. Comparison of Small Incision Lenticule Extraction Surgery With and Without Cyclotorsion Error Correction for Patients With Astigmatism. Cornea. 2019 Jun;38(6):723-729. doi: 10.1097/ICO.0000000000001937.
- Background: PubMed 35067664Wang B, Wang Y, Zhang J. Comparison of astigmatic correction with and without limbal marking during small-incision lenticule extraction. J Cataract Refract Surg. 2022 Aug 1;48(8):924-928. doi: 10.1097/j.jcrs.0000000000000889.
- Background: PubMed 38498276Yang X, Liu Y, Xiao K, Song Q, Xu Y, Li J, Zhou Y. Effect of Cyclotorsion Compensation in Small Incision Lenticule Extraction Surgery for the Correction of Myopic Astigmatism: A Systematic Review and Meta-Analysis. Ophthalmol Ther. 2024 May;13(5):1271-1288. doi: 10.1007/s40123-024-00921-2. Epub 2024 Mar 18.
- Individual participant dataSharing planned: No
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Manual limbal marking-guided cyclotorsion adjustment during SMILE in people with Myopia and Refractive Ametropia, run by Zhongshan Ophthalmic Center, Sun Yat-sen University 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: opening soon, as of the sponsor's last update on 15 Jul 2026. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Residual refractive astigmatism (time frame: 3 months after surgery). 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 NCT07696468, which also lists 3 linked publications.
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 15 Jul 2026.