Effect of Preoperative Pupil Size on Quality of Vision After Wavefront-Guided LASIK
April 28, 2009 updated by: Stanford University
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.
Study Overview
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 Type
Interventional
Enrollment (Actual)
51
Phase
- Phase 4
Contacts and Locations
This section provides the contact details for those conducting the study, and information on where this study is being conducted.
Study Locations
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California
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Stanford, California, United States, 94305
- Stanford University School of Medicine
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Participation Criteria
Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.
Eligibility Criteria
Ages Eligible for Study
- Child
- Adult
- Older Adult
Accepts Healthy Volunteers
No
Genders Eligible for Study
All
Description
Inclusion Criteria:
- 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
Exclusion Criteria:
- 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
- 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
Study Plan
This section provides details of the study plan, including how the study is designed and what the study is measuring.
How is the study designed?
Design Details
- Primary Purpose: Treatment
- Allocation: Non-Randomized
- Interventional Model: Single Group Assignment
- Masking: None (Open Label)
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Active Comparator: small
|
laser-assisted in situ keratomileusis
Other Names:
|
|
Active Comparator: medium
|
laser-assisted in situ keratomileusis
Other Names:
|
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Active Comparator: large
|
laser-assisted in situ keratomileusis
Other Names:
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Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Sponsor
Investigators
- Sub-Investigator: Annie Chan, Stanford University
Study record dates
These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.
Study Major Dates
Study Start
May 1, 2004
Primary Completion (Actual)
November 1, 2005
Study Completion (Actual)
November 1, 2005
Study Registration Dates
First Submitted
February 12, 2009
First Submitted That Met QC Criteria
April 28, 2009
First Posted (Estimate)
April 29, 2009
Study Record Updates
Last Update Posted (Estimate)
April 29, 2009
Last Update Submitted That Met QC Criteria
April 28, 2009
Last Verified
April 1, 2009
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- SU-02082009-1758
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.