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

NCT ID: NCT04738903

Last Updated: 2021-07-20

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 40 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2020-06-01
• Study Completion Date: 2021-06-30

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.

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.

Conditions

Patients With Myopic Spherical Equivalent up to -12 Diopters

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

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.

Group Type: ACTIVE_COMPARATOR

Femtosecond laser assisted LASIK eye surgery

Intervention Type: PROCEDURE

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.

Wave-front optimized (WFO) group

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

Group Type: ACTIVE_COMPARATOR

Femtosecond laser assisted LASIK eye surgery

Intervention Type: PROCEDURE

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.

Interventions

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.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

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

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Assiut University

OTHER

Sponsor Role: lead

Responsible Party

Mahmoud Abdel-Radi

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Mahmoud Abdel-Radi, MD

Role: PRINCIPAL_INVESTIGATOR

Assiut University

Locations

TIBA eye center

Asyut, , Egypt

Countries

Egypt

References

Piao J, Li YJ, Whang WJ, Choi M, Kang MJ, Lee JH, Yoon G, Joo CK. Comparative evaluation of visual outcomes and corneal asphericity after laser-assisted in situ keratomileusis with the six-dimension Amaris excimer laser system. PLoS One. 2017 Feb 10;12(2):e0171851. doi: 10.1371/journal.pone.0171851. eCollection 2017.

Reference Type: BACKGROUND

PMID: 28187180 (View on PubMed)

Mostafa MM, Abdelmotaal H, Abdelazeem K, Goda I, Abdel-Radi M. Q-value customized versus wavefront-optimized ablation in femtosecond laser-assisted LASIK for myopia and myopic astigmatism: a prospective contralateral comparative study. Eye Vis (Lond). 2022 Nov 2;9(1):43. doi: 10.1186/s40662-022-00312-3.

Reference Type: DERIVED

PMID: 36320050 (View on PubMed)

Other Identifiers

CQLASIK

Identifier Type: -

Identifier Source: org_study_id