Effect of Preoperative Pupil Size on Quality of Vision After Wavefront-Guided LASIK

Myopia Clinical Trial

Official title:

Effect of Preoperative Pupil Size on Quality of Vision After Wavefront-Guided LASIK

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00889941
• Other study ID #: SU-02082009-1758
• Status: Completed
• Phase: Phase 4
• First received: February 12, 2009
• Last updated: April 28, 2009
• Start date: May 2004
• Est. completion date: November 2005

Study information

• Verified date: April 2009
• Source: Stanford University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical 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.

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 information / eligibility

• Status: Completed
• Enrollment: 51
• Est. completion date: November 2005
• Est. primary completion date: November 2005
• Accepts healthy volunteers: No
• Gender: Both
• Age group: N/A and older

Eligibility

Inclusion Criteria:

1. no more than 6.00 D of spherical myopia

2. no more than 3.00 D of refractive astigmatism

3. a stable refraction (less than 0.50D per year of sphere or cylinder)

4. a corneal diameter of less than 11.0 mm to allow for suction ring fixation

5. discontinuation of soft contact wear at least 7 days prior to preoperative evaluation

6. visual acuity correctable to at least 20/20

7. age older than 21 years

8. ability to participate in follow-up examinations for 12 months after LASIK surgery

Exclusion Criteria:

1. use of rigid gas permeable contact lens

2. severe dry eye symptoms

3. severe blepharitis

4. anterior segment abnormalities (i.e. cataracts, corneal scarring, or neovascularization within 1 mm of intended ablation zone)

5. recurrent corneal erosion

6. severe basement membrane disease

7. progressive or unstable myopia or keratoconus

8. unstable corneal mires on central keratometry

9. corneal thickness in which LASIK procedure would result in less than 250 microns of remaining posterior corneal thickness below the flap postoperatively

10. baseline standard manifest refraction of more than 0.75 D in sphere power

11. or a difference of greater than 0.50 D in cylinder power compared with baseline standard cycloplegic refraction

12. a baseline standard cycloplegic refraction differing more than 0.75 in sphere, 0.50 D in cylinder

13. 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

14. 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

15. corneal warpage, or pellucid marginal degeneration)

16. previous intraocular or corneal surgery

17. history of herpes zoster or simplex keratitis

18. patients on systemic corticosteroid or immunosuppressive therapy

19. immunocompromised subjects or clinically significant atopic disease

20. connective tissue disease

21. diabetes

22. steroid responder

23. macular pathology

24. pregnant or lactating patients

25. patients with sensitivity to planned study concomitant medications

26. patients participating in another ophthalmic drug or device clinical trial

Study Design

Allocation: Non-Randomized, Endpoint Classification: Bio-equivalence Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Myopia

Intervention

Procedure:
• LASIK
laser-assisted in situ keratomileusis

Locations

Country	Name	City	State
United States	Stanford University School of Medicine	Stanford	California

Sponsors (1)

Lead Sponsor	Collaborator
Stanford University

Country where clinical trial is conducted

United States,