MyopiaNCT07512102
Comparison of Low- Versus High-Level Angle Kappa Compensation Strategies in SMILE Using the VisuMax 800: A Randomized Clinical Trial
A study testing Apply high compensation to the Kappa angle. and Apply low compensation to the Kappa angle. in people with Myopia and Refractive Ametropia, run by Zhongshan Ophthalmic Center, Sun Yat-sen University at 1 site in China.
Trial summary
The goal of this clinical trial is to compare two intraoperative kappa-angle compensation strategies during small incision lenticule extraction (SMILE) using the VisuMax 800 platform in patients with relatively large kappa-angle offsets. 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?
- Apply high compensation to the Kappa angle. and Apply low compensation to the Kappa angle.
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteChina
- Study dates
- 8 Apr 2026to 30 May 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 stable refractive status for >= 1 year, having myopia or myopic astigmatism, with refractive power within the range of SMILE procedure.
- Normal corneal morphology and corneal thickness meeting the surgical requirements.
- Best corrected visual acuity (CDVA) before surgery >= 1.0.
- The kappa angle-related offset coordinates (x, y) obtained before surgery, with the absolute value of either |x| or |yl| of any eye >= 0.20mm.
- Voluntary to undergo SMILE surgery on the VISUMAX800 platform, understanding the random grouping scheme and signing the informed consent form.
Who cannot join
- History of prior ocular surgery, significant ocular trauma, or presence of corneal or ocular diseases that may affect the safety of refractive surgery.
- Severe systemic diseases that may affect ocular healing or surgical safety.
- Females who are pregnant or lactating.
- Inability to cooperate as required to complete the procedure or follow-up visits.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Zhongshan Ophthalmic Center
Guangzhou, Guangdong, 510060
Guofu Huang, +86-20-66686748, huangguofu@gzzoc.com
About this study
The goal of this clinical trial is to compare two intraoperative kappa-angle compensation strategies during small incision lenticule extraction (SMILE) using the VisuMax 800 platform in patients with relatively large kappa-angle offsets.
Angle kappa represents the difference between the visual axis and the pupil center. In patients with a large offset, pupil-centered treatment may lead to decentration of the optical zone, which can induce higher-order aberrations and affect postoperative visual quality. The VisuMax 800 system allows intraoperative adjustment of the treatment center based on the measured offset, making different compensation strategies possible.
Read more
The main questions this study aims to answer are:
Does low kappa-angle compensation (50%) result in lower postoperative higher-order aberrations than high compensation (100%)? Does the compensation strategy influence visual acuity, refractive outcomes, contrast sensitivity, and subjective visual quality after SMILE? Are the measurements obtained from different diagnostic devices consistent when evaluating kappa-related parameters?
Researchers will compare SMILE with low compensation to SMILE with high compensation to determine which strategy provides better optical quality and visual performance.
Participants will:
Undergo SMILE surgery using either low or high kappa-angle compensation Complete scheduled postoperative examinations at 1 month, 3 months, and 6 months Receive measurements of visual acuity, refraction, higher-order aberrations, contrast sensitivity, and patient-reported visual outcomes Be monitored for safety outcomes and adverse events during follow-up
Read the detailed description
Angle kappa refers to the offset between the visual axis and the pupil center and is an important factor influencing the centration of the treatment zone during corneal refractive surgery. In patients with relatively large offsets, pupil-centered treatment may lead to decentered lenticule extraction, which can induce higher-order aberrations, especially coma, and may reduce postoperative visual quality.
Small incision lenticule extraction (SMILE) is a widely used corneal refractive procedure with good safety and predictability. The new-generation VisuMax 800 femtosecond laser system incorporates machine vision-assisted alignment, allowing the surgeon to adjust the treatment center according to the measured displacement between the corneal vertex and the pupil center. This enables intraoperative compensation based on the kappa-angle offset.
Previous studies in excimer laser surgery have evaluated different proportions of kappa-angle compensation, but prospective randomized studies in SMILE are limited, particularly in patients with relatively large offsets. In addition, the optimal amount of compensation during SMILE has not been clearly determined.
This study is a single-center, randomized, parallel-group clinical trial designed to compare two predefined compensation strategies during SMILE using the VisuMax 800 platform. Patients aged 18-40 years with stable myopia or myopic astigmatism and a kappa-related displacement of at least 0.20 mm will be enrolled and randomly assigned to one of two groups.
Participants in the low-compensation group will undergo SMILE with the treatment center shifted by 50% of the measured offset coordinates, while participants in the high-compensation group will undergo SMILE with 100% compensation of the measured offset. All surgeries will be performed using the same surgical protocol, and postoperative management will be identical in both groups.
Participants will undergo routine ophthalmic examinations before surgery and at scheduled follow-up visits after surgery. The primary evaluation will assess postoperative higher-order aberrations at 3 months. Secondary evaluations will include visual acuity, refractive outcomes, refractive stability, contrast sensitivity, patient-reported visual quality, optical zone centration, and safety outcomes. In addition, measurements obtained from different diagnostic devices will be compared to assess consistency.
The results of this study will help determine the optimal intraoperative compensation strategy for SMILE in patients with large kappa-angle offsets and may contribute to improving postoperative visual quality and refractive accuracy.
- Conditions
- Myopia, Refractive Ametropia
- Being tested
- Apply high compensation to the Kappa angle., Apply low compensation to the Kappa angle.
- Keywords
- myopia, SMILE, Refractive Surgery, Randomized Clinical Trial, Angle Kappa, VisuMax 800
- Medical subject headings
- Myopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Apply high compensation to the Kappa angle.Procedure or surgery
SMILE PRO is an upgraded version/procedural designation of SMILE (Small Incision Lenticule Extraction) performed on the ZEISS VisuMax 800 femtosecond laser platform. It remains, in essence, an all-femtosecond corneal refractive procedure. Its basic principle is to use a femtosecond laser to create a lenticule within the corneal stroma together with a small incision, and then remove the lenticule through that incision, thereby reshaping the corneal curvature to correct myopia and astigmatism. In the high-level compensation group, a high level of compensation for the kappa angle was applied during the preoperative parameter input.
Apply low compensation to the Kappa angle.Procedure or surgery
SMILE PRO is an upgraded version/procedural designation of SMILE (Small Incision Lenticule Extraction) performed on the ZEISS VisuMax 800 femtosecond laser platform. It is essentially an all-femtosecond corneal refractive procedure. Its basic principle is to use a femtosecond laser to create a lenticule within the corneal stroma and a small incision, and then remove the lenticule through the incision, thereby reshaping the corneal curvature to correct myopia and astigmatism. In the low-level compensation group, a low level of kappa-angle compensation was applied during the preoperative parameter input.
| Study group | Role | What they receive |
|---|---|---|
| Low-Level compensation group | Active comparator | Subjects underwent SMILE surgery on the VisuMax 800 platform. Preoperatively, decentration coordinates (x, y) were measured. While preserving the directional sign, the absolute value of the planned compensation was set to 50% of the measured decentration; the values were then rounded to the nearest increment permitted by the device input precision and entered into the system. All other surgical procedures, as well as postoperative medication and follow-up protocols, were performed according to a standardized regimen. Receives: Procedure: Apply low compensation to the Kappa angle. |
| High-Level compensation group | Experimental | Subjects also underwent SMILE surgery on the VisuMax 800 platform. Decentration coordinates (x, y) were measured, and the theoretical compensation was set at 100% of the measured decentration. While preserving the directional sign, the measured values were entered directly into the device without any additional adjustment. Except for the different compensation strategy, all other surgical procedures and postoperative management were identical to those of the low-compensation group. Receives: Procedure: Apply high compensation to the Kappa angle. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Coma aberration
Coma aberration measured by wavefront aberrometry to evaluate the effect of intraoperative kappa-angle compensation on postoperative optical quality.
Measured: 3 months after surgery
Secondary outcomes (10)
Higher-order aberrations
Total higher-order aberrations, spherical aberration, and trefoil aberration measured using wavefront aberrometry under standardized conditions to evaluate postoperative optical quality.
Measured: 1 month, 3 months, and 6 months after surgery
Optical zone decentration
Decentration of the optical zone measured using corneal topography by determining the displacement between the optical zone center and the corneal vertex.
Measured: 3 months after surgery
Visual Acuity
Binocular uncorrected distance visual acuity and corrected distance visual acuity measured using standardized visual acuity charts to evaluate visual performance and safety.
Measured: 1 month, 3 months, and 6 months after surgery
Manifest refraction
Postoperative sphere, cylinder, and spherical equivalent measured by manifest refraction.
Measured: 1 month, 3 months, and 6 months after surgery
Refractive accuracy
Proportion of eyes within predefined ranges of target refraction to evaluate refractive predictability.
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 visits.
Measured: 1 month to 6 months after surgery
Contrast sensitivity
Contrast sensitivity will be measured using a standardized contrast sensitivity testing system (CSV-1000, VectorVision, USA) at multiple spatial frequencies.
Measured: 3 months after surgery
Quality of Vision (QoV) score
Visual symptoms will be assessed using the Quality of Vision (QoV) questionnaire, which evaluates the frequency, severity, and bothersome nature of visual disturbances. Scores are recorded on ordinal scales, with higher scores indicating worse visual quality.
Measured: 3 months after surgery
Patient satisfaction score
Patient satisfaction will be assessed using a 5-point rating scale. Scores range from 1 to 5, with higher scores indicating greater satisfaction.
Measured: 3 months after surgery
Adverse events
Incidence of intraoperative or postoperative complications, including loss of corrected distance visual acuity and other clinically significant events.
Measured: Up to 6 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 posted6 Apr 2026
- Study start8 Apr 2026
- Primary completion30 May 2027 (estimated)
- Study completion30 May 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for MyopiaStudies of the same condition, open and under way.
- More trials run by Zhongshan Ophthalmic Center, Sun Yat-sen UniversityThe sponsor's other registered studies.
- 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
- 100 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07512102
- Sponsor's protocol ID
- IIT2025193
- Status last verified
- Mar 2026
- First submitted
- 21 Mar 2026
- Last updated
- 7 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Doostparast A, Ghandhari M, Rastegar M, Khosronejad AH, Ghandhari M, Eslampoor A. Distribution and inter-device agreement of chord mu/alpha lengths and axes between Pentacam HR, Sirius, and IOLMaster 700. Photodiagnosis Photodyn Ther. 2025 Dec;56:105275. doi: 10.1016/j.pdpdt.2025.105275. Epub 2025 Nov 6.
PubMed 41205666Shao T, Wang Y, Ng ALK, Chan TCY, Hao W, Zhang J, Cheng GPM, Jhanji V. The Effect of Intraoperative Angle Kappa Adjustment on Higher-Order Aberrations Before and After Small Incision Lenticule Extraction. Cornea. 2020 May;39(5):609-614. doi: 10.1097/ICO.0000000000002274.
PubMed 32040010Lai X, Liu X, Zeng T, Huang Y, Yang X. Comparison of visual outcomes and optical aberrations after SMILE with intraoperative Kappa angle adjustments between small and large Kappa angles. Sci Rep. 2024 Jun 24;14(1):14551. doi: 10.1038/s41598-024-65366-w.
PubMed 38914606Deng M, Zhou D, Li M, Shi Y, Sun L, Zou J, Ma X. Evaluation of corneal asymmetry and higher-order aberrations after small incision lenticule extraction for moderate and high myopia. Int Ophthalmol. 2025 Jun 1;45(1):218. doi: 10.1007/s10792-025-03576-5.
PubMed 40451982Vingopoulos F, Zisimopoulos A, Kanellopoulos AJ. Comparison of effective corneal refractive centration to the visual axis: LASIK vs SMILE, a contralateral eye digitized comparison of the postoperative result. J Cataract Refract Surg. 2021 Dec 1;47(12):1511-1518. doi: 10.1097/j.jcrs.0000000000000687.
PubMed 34074993McAlinden C, Pesudovs K, Moore JE. The development of an instrument to measure quality of vision: the Quality of Vision (QoV) questionnaire. Invest Ophthalmol Vis Sci. 2010 Nov;51(11):5537-45. doi: 10.1167/iovs.10-5341. Epub 2010 May 26.
PubMed 20505205Chang JS, Law AK, Ng JC, Chan VK. Comparison of refractive and visual outcomes with centration points 80% and 100% from pupil center toward the coaxially sighted corneal light reflex. J Cataract Refract Surg. 2016 Mar;42(3):412-9. doi: 10.1016/j.jcrs.2015.09.030.
PubMed 27063522
Study at a glance
From the registry record, last updated by the sponsor on 7 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Low- Versus High-Level Angle Kappa Compensation Strategies in SMILE Using the VisuMax 800: A Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT07512102
- Acronym / sponsor ID
- IIT2025193
- Conditions
- Myopia, Refractive Ametropia
- Keywords
- myopia, SMILE, Refractive Surgery, Randomized Clinical Trial, Angle Kappa, VisuMax 800
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Zhongshan Ophthalmic Center, Sun Yat-sen UniversityUniversity, hospital or other
- Study start
- 8 Apr 2026 (actual)
- Primary completion
- 30 May 2027 (estimated)
- Study completion
- 30 May 2027 (estimated)
- First posted
- 6 Apr 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.
The goal of this clinical trial is to compare two intraoperative kappa-angle compensation strategies during small incision lenticule extraction (SMILE) using the VisuMax 800 platform in patients with relatively large kappa-angle offsets.
Angle kappa represents the difference between the visual axis and the pupil center. In patients with a large offset, pupil-centered treatment may lead to decentration of the optical zone, which can induce higher-order aberrations and affect postoperative visual quality. The VisuMax 800 system allows intraoperative adjustment of the treatment center based on the measured offset, making different compensation strategies possible.
The main questions this study aims to answer are:
Does low kappa-angle compensation (50%) result in lower postoperative higher-order aberrations than high compensation (100%)? Does the compensation strategy influence visual acuity, refractive outcomes, contrast sensitivity, and subjective visual quality after SMILE? Are the measurements obtained from different diagnostic devices consistent when evaluating kappa-related parameters?
Researchers will compare SMILE with low compensation to SMILE with high compensation to determine which strategy provides better optical quality and visual performance.
Participants will:
Undergo SMILE surgery using either low or high kappa-angle compensation Complete scheduled postoperative examinations at 1 month, 3 months, and 6 months Receive measurements of visual acuity, refraction, higher-order aberrations, contrast sensitivity, and patient-reported visual outcomes Be monitored for safety outcomes and adverse events during follow-up
Detailed description
Angle kappa refers to the offset between the visual axis and the pupil center and is an important factor influencing the centration of the treatment zone during corneal refractive surgery. In patients with relatively large offsets, pupil-centered treatment may lead to decentered lenticule extraction, which can induce higher-order aberrations, especially coma, and may reduce postoperative visual quality.
Small incision lenticule extraction (SMILE) is a widely used corneal refractive procedure with good safety and predictability. The new-generation VisuMax 800 femtosecond laser system incorporates machine vision-assisted alignment, allowing the surgeon to adjust the treatment center according to the measured displacement between the corneal vertex and the pupil center. This enables intraoperative compensation based on the kappa-angle offset.
Previous studies in excimer laser surgery have evaluated different proportions of kappa-angle compensation, but prospective randomized studies in SMILE are limited, particularly in patients with relatively large offsets. In addition, the optimal amount of compensation during SMILE has not been clearly determined.
This study is a single-center, randomized, parallel-group clinical trial designed to compare two predefined compensation strategies during SMILE using the VisuMax 800 platform. Patients aged 18-40 years with stable myopia or myopic astigmatism and a kappa-related displacement of at least 0.20 mm will be enrolled and randomly assigned to one of two groups.
Participants in the low-compensation group will undergo SMILE with the treatment center shifted by 50% of the measured offset coordinates, while participants in the high-compensation group will undergo SMILE with 100% compensation of the measured offset. All surgeries will be performed using the same surgical protocol, and postoperative management will be identical in both groups.
Participants will undergo routine ophthalmic examinations before surgery and at scheduled follow-up visits after surgery. The primary evaluation will assess postoperative higher-order aberrations at 3 months. Secondary evaluations will include visual acuity, refractive outcomes, refractive stability, contrast sensitivity, patient-reported visual quality, optical zone centration, and safety outcomes. In addition, measurements obtained from different diagnostic devices will be compared to assess consistency.
The results of this study will help determine the optimal intraoperative compensation strategy for SMILE in patients with large kappa-angle offsets and may contribute to improving postoperative visual quality and refractive accuracy.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Low-Level compensation group | Active comparator | Procedure: Apply low compensation to the Kappa angle.Subjects underwent SMILE surgery on the VisuMax 800 platform. Preoperatively, decentration coordinates (x, y) were measured. While preserving the directional sign, the absolute value of the planned compensation was set to 50% of the measured decentration; the values were then rounded to the nearest increment permitted by the device input precision and entered into the system. All other surgical procedures, as well as postoperative medication and follow-up protocols, were performed according to a standardized regimen. |
| High-Level compensation group | Experimental | Procedure: Apply high compensation to the Kappa angle.Subjects also underwent SMILE surgery on the VisuMax 800 platform. Decentration coordinates (x, y) were measured, and the theoretical compensation was set at 100% of the measured decentration. While preserving the directional sign, the measured values were entered directly into the device without any additional adjustment. Except for the different compensation strategy, all other surgical procedures and postoperative management were identical to those of the low-compensation group. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Age range: 18 - 40 years old. Patients with stable refractive status for >= 1 year, having myopia or myopic astigmatism, with refractive power within the range of SMILE procedure.
- Normal corneal morphology and corneal thickness meeting the surgical requirements.
- Best corrected visual acuity (CDVA) before surgery >= 1.0.
- The kappa angle-related offset coordinates (x, y) obtained before surgery, with the absolute value of either |x| or |yl| of any eye >= 0.20mm.
- Voluntary to undergo SMILE surgery on the VISUMAX800 platform, understanding the random grouping scheme and signing the informed consent form.
Key exclusion criteria (4 listed)
- History of prior ocular surgery, significant ocular trauma, or presence of corneal or ocular diseases that may affect the safety of refractive surgery.
- Severe systemic diseases that may affect ocular healing or surgical safety.
- Females who are pregnant or lactating.
- Inability to cooperate as required to complete the procedure or follow-up visits.
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 |
|---|---|---|
| Apply high compensation to the Kappa angle.SMILE PRO is an upgraded version/procedural designation of SMILE (Small Incision Lenticule Extraction) performed on the ZEISS VisuMax 800 femtosecond laser platform. It remains, in essence, an all-femtosecond corneal refractive procedure. Its basic principle is to use a femtosecond laser to create a lenticule within the corneal stroma together with a small incision, and then remove the lenticule through that incision, thereby reshaping the corneal curvature to correct myopia and astigmatism. In the high-level compensation group, a high level of compensation for the kappa angle was applied during the preoperative parameter input. | Procedure or surgery | High-Level compensation group |
| Apply low compensation to the Kappa angle.SMILE PRO is an upgraded version/procedural designation of SMILE (Small Incision Lenticule Extraction) performed on the ZEISS VisuMax 800 femtosecond laser platform. It is essentially an all-femtosecond corneal refractive procedure. Its basic principle is to use a femtosecond laser to create a lenticule within the corneal stroma and a small incision, and then remove the lenticule through the incision, thereby reshaping the corneal curvature to correct myopia and astigmatism. In the low-level compensation group, a low level of kappa-angle compensation was applied during the preoperative parameter input. | Procedure or surgery | Low-Level compensation group |
Primary outcome
Coma aberration
Time frame: 3 months after surgery
Coma aberration measured by wavefront aberrometry to evaluate the effect of intraoperative kappa-angle compensation on postoperative optical quality.
10 secondary outcomes
Higher-order aberrations
Time frame: 1 month, 3 months, and 6 months after surgery
Optical zone decentration
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
Contrast sensitivity
Time frame: 3 months after surgery
Quality of Vision (QoV) score
Time frame: 3 months after surgery
Patient satisfaction score
Time frame: 3 months after surgery
Adverse events
Time frame: Up to 6 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 7 Jul 2026.
- Background: PubMed 41205666Doostparast A, Ghandhari M, Rastegar M, Khosronejad AH, Ghandhari M, Eslampoor A. Distribution and inter-device agreement of chord mu/alpha lengths and axes between Pentacam HR, Sirius, and IOLMaster 700. Photodiagnosis Photodyn Ther. 2025 Dec;56:105275. doi: 10.1016/j.pdpdt.2025.105275. Epub 2025 Nov 6.
- Background: PubMed 32040010Shao T, Wang Y, Ng ALK, Chan TCY, Hao W, Zhang J, Cheng GPM, Jhanji V. The Effect of Intraoperative Angle Kappa Adjustment on Higher-Order Aberrations Before and After Small Incision Lenticule Extraction. Cornea. 2020 May;39(5):609-614. doi: 10.1097/ICO.0000000000002274.
- Background: PubMed 38914606Lai X, Liu X, Zeng T, Huang Y, Yang X. Comparison of visual outcomes and optical aberrations after SMILE with intraoperative Kappa angle adjustments between small and large Kappa angles. Sci Rep. 2024 Jun 24;14(1):14551. doi: 10.1038/s41598-024-65366-w.
- Background: PubMed 40451982Deng M, Zhou D, Li M, Shi Y, Sun L, Zou J, Ma X. Evaluation of corneal asymmetry and higher-order aberrations after small incision lenticule extraction for moderate and high myopia. Int Ophthalmol. 2025 Jun 1;45(1):218. doi: 10.1007/s10792-025-03576-5.
- Background: PubMed 34074993Vingopoulos F, Zisimopoulos A, Kanellopoulos AJ. Comparison of effective corneal refractive centration to the visual axis: LASIK vs SMILE, a contralateral eye digitized comparison of the postoperative result. J Cataract Refract Surg. 2021 Dec 1;47(12):1511-1518. doi: 10.1097/j.jcrs.0000000000000687.
- Background: PubMed 20505205McAlinden C, Pesudovs K, Moore JE. The development of an instrument to measure quality of vision: the Quality of Vision (QoV) questionnaire. Invest Ophthalmol Vis Sci. 2010 Nov;51(11):5537-45. doi: 10.1167/iovs.10-5341. Epub 2010 May 26.
- Background: PubMed 27063522Chang JS, Law AK, Ng JC, Chan VK. Comparison of refractive and visual outcomes with centration points 80% and 100% from pupil center toward the coaxially sighted corneal light reflex. J Cataract Refract Surg. 2016 Mar;42(3):412-9. doi: 10.1016/j.jcrs.2015.09.030.
- 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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Apply high compensation to the Kappa angle. and Apply low compensation to the Kappa angle. 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 5 inclusion and 4 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: looking for participants now, as of the sponsor's last update on 7 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?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Coma aberration (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 NCT07512102, which also lists 7 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 7 Jul 2026; AzTrials last refreshed its copy on 7 Nov 2026.