MyopiaNCT01252654
Comparison of Intralase and Visumax Femtosecond Laser for Laser In Situ Keratomileusis
An observational study of Myopia, run by Singapore Eye Research Institute at 1 site in Singapore.
Trial summary
Emtosecond lasers are used in cutting the flap in LASIK procedures (laser corrective surgery for refractive error). Their use has decreased the incidence of serious complications when compared to the use of microkeratomes(mechanical blades). The commonest femtosecond laser currently used is 'Intralase'. Read more about this study
- Who is it for?
- Ages 21 to 60 years
- Conditions the study is for
- Myopia
- How many people
- 120 participants
- Where
- 1 siteSingapore
- Study dates
- Jan 2010to Aug 2013
- Phase
- Observational
- Are there results?
- None posted in the registry
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 21 to 60 years
- All sexes
- No healthy volunteers
- Adult
Study population: Myopic patients presenting to refractive service eligible for LASIK
Who may be able to join
- 21 years of age or older.
- Cycloplegic spherical equivalent of >-1.00D
- Refractive cylinder -4.00 D or less.
- Best spectacle corrected visual acuity (BSCVA) of 6/12 or better in BOTH eyes.
- Spherical or cylindrical error has progressed at -0.50D or less per year from date of baseline measurement.
- Contact lens wearers must have removed contact lenses at least two (2) weeks before the baseline measurement.
- No evidence of irregular astigmatism on corneal topography.
- Available to attend post-operative examinations for a 3 month period.
Who cannot join
- Progressive or unstable myopia and/or astigmatism.
- Clinical or corneal topographic evidence of keratoconus.
- Residual, recurrent or active ocular disease such as uveitis, severe dry eyes, severe allergic eye disease, glaucoma, visually significant cataract and retinal disease.
- Previous corneal surgery or trauma within the corneal flap zone.
- Patent corneal vascularization within 1mm of the corneal flap zone.
- Taking systemic medications likely to affect wound healing, such as corticosteroids and antimetabolites.
Show all 9Show fewer
- Systemically immunocompromised.
- Systemic disease likely to affect wound healing, such as diabetes, connective tissue disease and severe atopy.
- Pregnant or nursing.
Trial locations and contacts
1 site in 1 country.
About this study
Emtosecond lasers are used in cutting the flap in LASIK procedures (laser corrective surgery for refractive error). Their use has decreased the incidence of serious complications when compared to the use of microkeratomes(mechanical blades). The commonest femtosecond laser currently used is 'Intralase'. A newer femtosecond laser 'Visumax' (Zeiss) is now available and differs from the Intralase in that it does not interfere with the curvature of the cornea when creating the flap. The Intralase applanates the cornea flat during flap creation which causes the intraocular pressure to be higher. Both Intralase and Visumax lasers are available to patients and surgeons to use at SNEC. The aim of the investigators study is to compare the two lasers in a randomization of left and right eyes in the same patient. The investigators want to measure any difference that the lower intraocular pressure may have during the creation of the flap. This will be measured with a questionaire on patient experience during the procedure and the outcomes of vision, refraction, contrast sensitivity, wave-front analysis, tear function,corneal sensation and flap thickness measured with anterior segment OCT during the post-operative follow up period. To date no-one has compared the use of these two femtosecond lasers. Both lasers are currently used clinically for flap creation at SNEC.
- Conditions
- Myopia
- Keywords
- Lasik, Femtosecond Laser, Visumax, IntraLase, Myopia, Myopic Patients undergoing LASIK
- Medical subject headings
- Myopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| 1 IntraLase flaps | Patients who have undergone flap creation with IntraLase laser | |
| 2 Visumax flaps | Patients who have undergone flaps created with Visumax laser |
What is being measured
The primary outcome is the main question the study is designed to answer.
Visual Acuity
Measured: 3 months
Secondary outcomes (6)
complications
Measured: 3 months
Subjective questionnaire
Measured: 1 weekd
Corneal Sensation
Measured: 3 months
Tear function
Measured: 3 months
Wavefront analysis
Measured: 3 months
Contrast Sensitivity
Measured: 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Dec 2010 (estimated)
- Study startJan 2010
- Primary completionAug 2012
- Study completionAug 2013
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)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
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 120 participants (actual)
Sponsor and investigators
- Lead sponsor
- Singapore Eye Research Institute
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jodhbir Mehta, Singapore Eye Research Institute
- Investigators
- Donald Tan, Principal investigator, Singapore National Eye Centre
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01252654
- Sponsor's protocol ID
- R683/33/2009
- Other IDs
- Other
- Status last verified
- Jul 2016
- First submitted
- 10 May 2010
- Last updated
- 24 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
Publications
D'Souza S, Petznick A, Tong L, Hall RC, Rosman M, Chan C, Koh SK, Beuerman RW, Zhou L, Mehta JS. Comparative analysis of two femtosecond LASIK platforms using iTRAQ quantitative proteomics. Invest Ophthalmol Vis Sci. 2014 May 6;55(6):3396-402. doi: 10.1167/iovs.14-14113.
PubMed 24801511
Study at a glance
From the registry record, last updated by the sponsor on 24 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Intralase and Visumax Femtosecond Laser for Laser In Situ Keratomileusis
- ClinicalTrials.gov ID
- NCT01252654
- Acronym / sponsor ID
- R683/33/2009
- Conditions
- Myopia
- Keywords
- Lasik, Femtosecond Laser, Visumax, IntraLase, Myopia, Myopic Patients undergoing LASIK
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 120 participants (actual)
- Lead sponsor
- Singapore Eye Research InstituteUniversity, hospital or other
- Study start
- Jan 2010
- Primary completion
- Aug 2012 (actual)
- Study completion
- Aug 2013 (actual)
- First posted
- 3 Dec 2010 (estimated)
- 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.
Emtosecond lasers are used in cutting the flap in LASIK procedures (laser corrective surgery for refractive error). Their use has decreased the incidence of serious complications when compared to the use of microkeratomes(mechanical blades). The commonest femtosecond laser currently used is 'Intralase'. A newer femtosecond laser 'Visumax' (Zeiss) is now available and differs from the Intralase in that it does not interfere with the curvature of the cornea when creating the flap. The Intralase applanates the cornea flat during flap creation which causes the intraocular pressure to be higher. Both Intralase and Visumax lasers are available to patients and surgeons to use at SNEC. The aim of the investigators study is to compare the two lasers in a randomization of left and right eyes in the same patient. The investigators want to measure any difference that the lower intraocular pressure may have during the creation of the flap. This will be measured with a questionaire on patient experience during the procedure and the outcomes of vision, refraction, contrast sensitivity, wave-front analysis, tear function,corneal sensation and flap thickness measured with anterior segment OCT during the post-operative follow up period. To date no-one has compared the use of these two femtosecond lasers. Both lasers are currently used clinically for flap creation at SNEC.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 1 IntraLase flaps | – | –Patients who have undergone flap creation with IntraLase laser |
| 2 Visumax flaps | – | –Patients who have undergone flaps created with Visumax laser |
Who may qualify
- Ages
- 21 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Myopic patients presenting to refractive service eligible for LASIK
Key inclusion criteria (8 listed)
- 21 years of age or older.
- Cycloplegic spherical equivalent of >-1.00D
- Refractive cylinder -4.00 D or less.
- Best spectacle corrected visual acuity (BSCVA) of 6/12 or better in BOTH eyes.
- Spherical or cylindrical error has progressed at -0.50D or less per year from date of baseline measurement.
Key exclusion criteria (9 listed)
- Progressive or unstable myopia and/or astigmatism.
- Clinical or corneal topographic evidence of keratoconus.
- Residual, recurrent or active ocular disease such as uveitis, severe dry eyes, severe allergic eye disease, glaucoma, visually significant cataract and retinal disease.
- Previous corneal surgery or trauma within the corneal flap zone.
- Patent corneal vascularization within 1mm of the corneal flap zone.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Visual Acuity
Time frame: 3 months
6 secondary outcomes
complications
Time frame: 3 months
Subjective questionnaire
Time frame: 1 weekd
Corneal Sensation
Time frame: 3 months
Tear function
Time frame: 3 months
Wavefront analysis
Time frame: 3 months
Contrast Sensitivity
Time frame: 3 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Apr 2026.
- Derived from this study: PubMed 24801511D'Souza S, Petznick A, Tong L, Hall RC, Rosman M, Chan C, Koh SK, Beuerman RW, Zhou L, Mehta JS. Comparative analysis of two femtosecond LASIK platforms using iTRAQ quantitative proteomics. Invest Ophthalmol Vis Sci. 2014 May 6;55(6):3396-402. doi: 10.1167/iovs.14-14113.
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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. This study is not recruiting at the moment.
Donald Tan principal investigator
Singapore National Eye Centre
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Myopia, run by Singapore Eye Research Institute at 1 site in Singapore.
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 8 inclusion and 9 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: finished, as of the sponsor's last update on 24 Apr 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 Singapore. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Visual Acuity (time frame: 3 months). 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 NCT01252654, which also lists 1 linked publication.
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 24 Apr 2026.