Q Value Customized Versus Wavefront Optimized Ablation in Femtosecond Laser-Assisted LASIK

Sponsor
Assiut University (Other)
Overall Status
Completed
CT.gov ID
NCT04738903
Collaborator
(none)
40
1
2
12.9
3.1

Study Details

Study Description

Brief Summary

Corneal asphericity is expressed numerically as the "Q-value". A minus value means that corneal curvature flattens towards the periphery and the cornea is prolate in shape, but when the curvature steepens towards the periphery, the cornea is oblate in shape and has a positive Q-value.

The current study evaluates the effect of LASIK eye surgery on corneal asphericity by comparing 2 software treatment platforms; the Q value customized ablation versus the conventional Wave-front optimized ablation in a fellow eye study pattern.

Condition or Disease Intervention/Treatment Phase
  • Procedure: Femtosecond laser assisted LASIK eye surgery
N/A

Detailed Description

The standard excimer laser correction of myopia is associated with decreased visual quality in the form of a decrease in contrast sensitivity and night vision. This degradation of the visual quality is attributed to changes in the corneal asphericity that increase the high order aberrations (HOAs), such as spherical aberrations because it leads to shifting of the corneal asphericity towards the oblate shape.

The wavefront-optimized (WFO) profile avoids the creation of new HOAs, but it is not able to treat those which are already present pre-operatively.

The Q-adjusted treatments correct the sphero-cylindrical refractive errors and try to maintain the corneal asphericity at the same time, but like the WFO ablation profiles, it is limited to correcting the spherical aberrations and not the non-rotational symmetric HOAs.

Some studies compared Lasers of two different platforms on contralateral eyes of the same patient in order to minimize inter-patient differences such as corneal wound healing and corneal biomechanics. By exclusion of these inter-patient differences, a more accurate judgment on the outcomes can be achieved.

Study Design

Study Type:
Interventional
Actual Enrollment :
40 participants
Allocation:
Non-Randomized
Intervention Model:
Parallel Assignment
Masking:
Single (Outcomes Assessor)
Primary Purpose:
Treatment
Official Title:
Q Value Customized Versus Wavefront Optimized Ablation in Femtosecond Laser-Assisted LASIK for Myopia and Myopic Astigmatism. A Contralateral Comparative Study
Actual Study Start Date :
Jun 1, 2020
Actual Primary Completion Date :
Jun 30, 2021
Actual Study Completion Date :
Jun 30, 2021

Arms and Interventions

Arm Intervention/Treatment
Active Comparator: Custom Q treatment group

For every patient, the eye with the greater myopic spherical equivalent (SE) will be assigned for the Custom-Q treatment group.

Procedure: Femtosecond laser assisted LASIK eye surgery
FS-LASIK eye surgery includes corneal flap creation with femtosecond laser using the Femtosecond laser WaveLight FS200 followed by excimer laser vision correction of the patient's refractive error using excimer laser WaveLight EX500.

Active Comparator: Wave-front optimized (WFO) group

For every patient, the other eye with the lesser myopic SE will be assigned for the WFO treatment group

Procedure: Femtosecond laser assisted LASIK eye surgery
FS-LASIK eye surgery includes corneal flap creation with femtosecond laser using the Femtosecond laser WaveLight FS200 followed by excimer laser vision correction of the patient's refractive error using excimer laser WaveLight EX500.

Outcome Measures

Primary Outcome Measures

  1. Postoperative Q value [6 months]

    Pentacam evaluation of post-LASIK Q value

Secondary Outcome Measures

  1. Postoperative corneal thickness at the pupillary center [6 months]

    Pentacam evaluation of post-LASIK pachymetry at the pupil center

Eligibility Criteria

Criteria

Ages Eligible for Study:
18 Years and Older
Sexes Eligible for Study:
All
Accepts Healthy Volunteers:
Yes

Inclusion Criteria: Candidates for Laser vision correction (LVC) with

  1. Myopic Spherical Equivalent up to -12 diopters.

  2. Myopic astigmatism up to -6 diopters.

  3. Corneal thinnest location ≥ 500 um 4- Residual stromal bed ≥ 300 um.

Exclusion Criteria:
  1. Patients not candidates for LVC.

  2. Hyperopic patients or mixed astigmatism.

  3. Systemic disease that contraindicates LVC.

  4. Intra- or post-operative complications. 5- Previous corneal surgery

Contacts and Locations

Locations

Site City State Country Postal Code
1 TIBA eye center Assiut Egypt 71516

Sponsors and Collaborators

  • Assiut University

Investigators

  • Principal Investigator: Mahmoud Abdel-Radi, MD, Assiut University

Study Documents (Full-Text)

None provided.

More Information

Publications

Responsible Party:
Mahmoud Abdel-Radi, Principal Investigator, Assiut University
ClinicalTrials.gov Identifier:
NCT04738903
Other Study ID Numbers:
  • CQLASIK
First Posted:
Feb 4, 2021
Last Update Posted:
Jul 20, 2021
Last Verified:
Jul 1, 2021
Individual Participant Data (IPD) Sharing Statement:
No
Plan to Share IPD:
No
Studies a U.S. FDA-regulated Drug Product:
No
Studies a U.S. FDA-regulated Device Product:
No
Keywords provided by Mahmoud Abdel-Radi, Principal Investigator, Assiut University
Additional relevant MeSH terms:

Study Results

No Results Posted as of Jul 20, 2021