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

Not Recruiting

Trial ID: NCT00889941


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.

Official Title

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

Stanford Investigator(s)

Edward Manche, MD
Edward Manche, MD

Professor of Ophthalmology


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

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


procedure: LASIK

Not Recruiting

Contact Information

Stanford University
School of Medicine
300 Pasteur Drive
Stanford, CA 94305
Edward Manche