MyopiaPhase 4NCT00889941
Effect of Preoperative Pupil Size on Quality of Vision After Wavefront-Guided LASIK
A Phase 4 study testing LASIK in people with Myopia, run by Stanford University at 1 site in United States.
Trial summary
The purpose of this study is to evaluate whether the size of the pupil has an effect on quality of vision in patients undergoing LASIK surgery. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Myopia
- What is being tested?
- LASIK
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 51 participants
- Where
- 1 siteUnited States
- Study dates
- May 2004to Nov 2005
- Phase
- Phase 4
- 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 Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- no more than 6.00 D of spherical myopia
- no more than 3.00 D of refractive astigmatism
- a stable refraction (less than 0.50D per year of sphere or cylinder)
- a corneal diameter of less than 11.0 mm to allow for suction ring fixation
- discontinuation of soft contact wear at least 7 days prior to preoperative evaluation
- visual acuity correctable to at least 20/20
- age older than 21 years
- ability to participate in follow-up examinations for 12 months after LASIK surgery
Who cannot join
- use of rigid gas permeable contact lens
- severe dry eye symptoms
- severe blepharitis
- anterior segment abnormalities (i.e. cataracts, corneal scarring, or neovascularization within 1 mm of intended ablation zone)
- recurrent corneal erosion
- severe basement membrane disease
Show all 26Show fewer
- progressive or unstable myopia or keratoconus
- unstable corneal mires on central keratometry
- corneal thickness in which LASIK procedure would result in less than 250 microns of remaining posterior corneal thickness below the flap postoperatively
- baseline standard manifest refraction of more than 0.75 D in sphere power
- or a difference of greater than 0.50 D in cylinder power compared with baseline standard cycloplegic refraction
- a baseline standard cycloplegic refraction differing more than 0.75 in sphere, 0.50 D in cylinder
- have a different type of astigmatism (i.e. with-the-rule) when the cylinder is greater than 0.50D compared to baseline standard cycloplegic refraction
- preoperative assessment of ocular topography and/or aberrations indicates that either eye is not suitable candidate for LASIK vision correction procedure (i.e. forme fruste keratoconus
- corneal warpage, or pellucid marginal degeneration)
- previous intraocular or corneal surgery
- history of herpes zoster or simplex keratitis
- patients on systemic corticosteroid or immunosuppressive therapy
- immunocompromised subjects or clinically significant atopic disease
- connective tissue disease
- diabetes
- steroid responder
- macular pathology
- pregnant or lactating patients
- patients with sensitivity to planned study concomitant medications
- patients participating in another ophthalmic drug or device clinical trial
Trial locations and contacts
1 site in 1 country.
United States1 site
Stanford University School of Medicine
Stanford, California, 94305
About this study
The purpose of this study is to evaluate whether the size of the pupil has an effect on quality of vision in patients undergoing LASIK surgery.
Read the detailed description
Purpose: To prospectively evaluate the effect of preoperative pupil size on quality of vision after wavefront-guided LASIK.
Methods: Fifty-one patients underwent LASIK for low myopia and completed questionnaires regarding specific visual symptoms before and after surgery. Each eye was evaluated postoperatively at 1-week, 1-, 3-, 6- and 12-months. Pupils were stratified according to size: small (<5.5mm), medium (5.5 to 6.0mm) and large (>6.0mm). Mesopic pupil size and preoperative and postoperative variables were evaluated using analysis of variance (ANOVA). A regression model was also performed to determine the correlation between mean spherical equivalent and cylinder and visual symptoms.
- Conditions
- Myopia
- Being tested
- LASIK
- Medical subject headings
- Myopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
LASIKProcedure or surgery
Also called laser-assisted in situ keratomileusis
laser-assisted in situ keratomileusis
| Study group | Role | What they receive |
|---|---|---|
| small | Active comparator | Not described Receives: Procedure: LASIK |
| medium | Active comparator | Not described Receives: Procedure: LASIK |
| large | Active comparator | Not described Receives: Procedure: LASIK |
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Apr 2009 (estimated)
- Study startMay 2004
- Primary completionNov 2005
- Study completionNov 2005
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for MyopiaStudies of the same condition, open and under way.
- More trials run by Stanford 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 4
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 51 participants (actual)
Sponsor and investigators
- Lead sponsor
- Stanford University
- Sponsor type
- University, hospital or other
- Investigators
- Annie Chan, Sub-investigator, Stanford UniversityEdward E. Manche, Principal investigator, Stanford University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00889941
- Sponsor's protocol ID
- SU-02082009-1758
- Status last verified
- Apr 2009
- First submitted
- 12 Feb 2009
- Last updated
- 29 Apr 2009
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 29 Apr 2009. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Preoperative Pupil Size on Quality of Vision After Wavefront-Guided LASIK
- ClinicalTrials.gov ID
- NCT00889941
- Acronym / sponsor ID
- SU-02082009-1758
- Conditions
- Myopia
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 51 participants (actual)
- Lead sponsor
- Stanford UniversityUniversity, hospital or other
- Study start
- May 2004
- Primary completion
- Nov 2005 (actual)
- Study completion
- Nov 2005 (actual)
- First posted
- 29 Apr 2009 (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.
The purpose of this study is to evaluate whether the size of the pupil has an effect on quality of vision in patients undergoing LASIK surgery.
Detailed description
Purpose: To prospectively evaluate the effect of preoperative pupil size on quality of vision after wavefront-guided LASIK.
Methods: Fifty-one patients underwent LASIK for low myopia and completed questionnaires regarding specific visual symptoms before and after surgery. Each eye was evaluated postoperatively at 1-week, 1-, 3-, 6- and 12-months. Pupils were stratified according to size: small (<5.5mm), medium (5.5 to 6.0mm) and large (>6.0mm). Mesopic pupil size and preoperative and postoperative variables were evaluated using analysis of variance (ANOVA). A regression model was also performed to determine the correlation between mean spherical equivalent and cylinder and visual symptoms.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| small | Active comparator | Procedure: LASIK |
| medium | Active comparator | Procedure: LASIK |
| large | Active comparator | Procedure: LASIK |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (8 listed)
- no more than 6.00 D of spherical myopia
- no more than 3.00 D of refractive astigmatism
- a stable refraction (less than 0.50D per year of sphere or cylinder)
- a corneal diameter of less than 11.0 mm to allow for suction ring fixation
- discontinuation of soft contact wear at least 7 days prior to preoperative evaluation
Key exclusion criteria (26 listed)
- use of rigid gas permeable contact lens
- severe dry eye symptoms
- severe blepharitis
- anterior segment abnormalities (i.e. cataracts, corneal scarring, or neovascularization within 1 mm of intended ablation zone)
- recurrent corneal erosion
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 |
|---|---|---|
| LASIKAlso: laser-assisted in situ keratomileusislaser-assisted in situ keratomileusis | Procedure or surgery | large, medium, small |
Primary outcome
Not reported in the source record.
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 29 Apr 2009.
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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.
Annie Chan sub-investigator
Stanford University
Edward E. Manche principal investigator
Stanford University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing LASIK in people with Myopia, run by Stanford University at 1 site in United States.
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 26 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 29 Apr 2009. 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 United States. 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.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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.
Where can I read the original study information?
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 29 Apr 2009.