Status:
UNKNOWN
Aberration-Free Refraction Correction
Lead Sponsor:
National Taiwan University Hospital
Conditions:
Myopia
Eligibility:
All Genders
Brief Summary
In the interest of improving visual quality after LASIK we have designed a multifaceted study to test the theoretical, physical, biomechanical and functional effects of commercial and independently de...
Detailed Description
The quality of an image on the retina is determined by the optical system of the eyeball, which is dominated by the refractive contribution of the optically powerful cornea. The large difference in re...
Eligibility Criteria
Inclusion
- This will be a prospective study including at least 60 patients. The initial study group will include 6-10 patients. Both eyes of enrolled patients should be included in the study unless exclusion criteria prevent it. The primary efficacy variables for this study are wavefront error, visual acuity, autorefraction and contrast sensitivity. Subjects will be followed over a 3 month period. A proposed examination schedule is listed in Table 1.
- Eyes will also be divided into groups by refractive error: Low myopia 0-3D, moderate myopia 3-6D, and high myopia 6-9 D and very high myopia \> 9D MSRE. The size of the Optical Zone and Transitional Zone is measured, and results are compared for patients of similar refractive error (+/- 0.5 S +/- 0.5 C). Analysis is carried out using a matrix analysis of the total refractive error, comparison of Visual Acuity, Contrast Sensitivity and Responses on a Questionnaire to assess the patient's quality of vision.
- Equal numbers of eyes from each of the four refractive error groups and from each of the three treatment groups (OATZ profile 5, OATZ profile 6, conventional) will be measured.
- We will consider patients operated on by the same doctor (Dr. Lin). We will also compare treatments of patients and wavefront maps of patients who have similar spherical and cylindrical refractive errors.
- Table 1. Examination Schedule (Definitions) Visit Time Preoperative Within 30 days of surgery Operative Day Day of surgery
- 1 Month postop 3-5 weeks following surgery 3 Months postop 10-14 weeks following surgery
Exclusion
- Patients will be excluded if they have a history of ocular pathology, previous ocular surgery, thin corneas (preoperatively calculated minimal residual bed \< 250um) or fit into the group of the usual exclusionary criteria (e.g. irregular astigmatism, asymmetric astigmatism, unstable refraction).
- Possible additional exclusion criteria include no previous refractive surgery, no hyperopia, preop BSCVA 20/25 or better, ages from 21-60 years old, astigmatism above 2D, difficult cases and equal numbers of men and women
Key Trial Info
Start Date :
June 1 2005
Trial Type :
OBSERVATIONAL
End Date :
July 1 2008
Estimated Enrollment :
60 Patients enrolled
Trial Details
Trial ID
NCT00172913
Start Date
June 1 2005
End Date
July 1 2008
Last Update
September 15 2005
Active Locations (1)
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1
National Taiwan University Hospital
Taipei, Taiwan