Effect of Preoperative Pupil Size on Quality of Vision After Wavefront-Guided LASIK
- Conditions
- Myopia
- Interventions
- Procedure: LASIK
- Registration Number
- NCT00889941
- Lead Sponsor
- Stanford University
- Brief 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.
- 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.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 51
- 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
- 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 & Design
- Study Type
- INTERVENTIONAL
- Study Design
- SINGLE_GROUP
- Arm && Interventions
Group Intervention Description small LASIK - medium LASIK - large LASIK -
- Primary Outcome Measures
Name Time Method
- Secondary Outcome Measures
Name Time Method
Trial Locations
- Locations (1)
Stanford University School of Medicine
🇺🇸Stanford, California, United States