Contoura vs Wavefront Optimized Ablation

April 24, 2023 updated by: Hebatallah MT Abdelmoniem

Contoura Topography-guided Ablation Versus Wavefront-optimized Ablation for Correction of Astigmatism

To evaluate the efficacy, safety and accuracy of Contoura topography-guided LASIK & PRK in comparison to Wavefront optimized LASIK & PRK in virgin eyes with astigmatism.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

In Upper Egypt, The second principal cause of blindness was uncorrected refractive errors accounting for 16% of sample population. It was reported that astigmatism (defined as cylinder power > 0.5 D) was the most common refractive errors in children and adults followed by hyperopia and myopia.

Laser vision correction has been established over the last 2 decades as a safe and effective intervention to treat refractive errors, being one of the main techniques practiced globally.

However, many subjects after LASIK had uncorrected distance visual acuity (UDVA) greater than 1.0, they complain about poor night vision, glare, and double vision. As studies have shown that every 1° deviation of the astigmatic axis could result in loss of correction of 3.3%. Even residual astigmatism less than 0.50D could have an actual impact on visual quality.

Excimer laser ablation used in the correction of refracted errors especially astigmatism may reduce quality of vision, and that is attributed to the induced optical aberrations. The most prevalent of these optical aberrations is the spherical aberration.

Among multiple sophisticated profiles that developed to optimize visual outcomes, wavefront optimized profile which compensate for corneal curvature to reduce spherical aberration.

The topographic guided profiles which consider the shape of the anterior corneal surface. Contoura topography guided ablation corrects astigmatic power and axis to create a more uniform, aberration-free cornea.

Treating astigmatism can be challenging as the conventional patterns of Excimer laser treatment of astigmatism is known to be less predictable than that of spherical refractive errors.

Study Type

Observational

Enrollment (Anticipated)

128

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

N/A

Sampling Method

Non-Probability Sample

Study Population

participants who are candidates and scheduled for excimer laser treatment either LASIK or PRK

Description

Inclusion Criteria:

  • Astigmatism (up to 5.0 diopters) or less.
  • Central corneal thickness (CCT) of 500 microns or more
  • Estimated Residual stromal bed thickness (RSB) of 280 microns or more
  • Subject has provided written informed consent

Exclusion Criteria:

  • Keratoconus
  • Abnormal topography
  • previous ocular trauma or eye surgery
  • pre-existing diseases of the vitreous, macula, or optic nerve that can affect visual outcome
  • patients with uveitis and anterior segment pathology
  • patients with corneal pathology or Severe dry eye
  • pregnancy or breast-feeding females
  • uncontrolled vascular or autoimmune disease

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Group A
Contoura topography-guided LASIK
Procedure: Laser assisted in-situ keratomileusis
Laser-Assisted In Situ Keratomileusis is a procedure that permanently changes the shape of the cornea using an excimer laser and the mechanical microkeratome (a blade device) used to cut a flap in the cornea.
Other Names:
  • LASIK
Group B
Contoura topography-guided PRK
Procedure: Photorefractive keratectomy
Photorefractive keratectomy is a laser refractive procedure used to ablate the corneal stroma to correct refractive errors without cutting flap
Other Names:
  • PRK
Group C
Wavefront-optimized LASIK
Procedure: Laser assisted in-situ keratomileusis
Laser-Assisted In Situ Keratomileusis is a procedure that permanently changes the shape of the cornea using an excimer laser and the mechanical microkeratome (a blade device) used to cut a flap in the cornea.
Other Names:
  • LASIK
Group D
Wavefront-optimized PRK
Procedure: Photorefractive keratectomy
Photorefractive keratectomy is a laser refractive procedure used to ablate the corneal stroma to correct refractive errors without cutting flap
Other Names:
  • PRK

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Postoperative UDVA compared to preoperative CDVA (in LogMAR)
Time Frame: 3 month
UCVA 3 month after surgery compared to baseline preoperative CDVA
3 month
Number of lines of preoperative CDVA compared to postoperative
Time Frame: 3 month
Change in lines of CDVA from baseline preoperative to 3 month postoperative (in LogMAR)
3 month
Amount of Residual Astigmatism postoperatively (in Diopters)
Time Frame: 3 month
residual astigmatism 3 month postoperatively
3 month
Postoperative mean spherical equivalent MSE compared to Preoperative MSE (in Diopters)
Time Frame: 3 month
changes in mean spherical equivalent baseline preoperative to 3 month postoperative
3 month

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Contrast sensitivity test
Time Frame: 3 month
3 month
Amount of High order aberrations
Time Frame: 3 month
(Spherical aberration, trefoil, vertical & horizontal coma)
3 month

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hebatallah MT Abdelmoniem

Investigators

  • Study Chair: Mohamed A. Sayed, Ass. Prof., Assiut University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Anticipated)

June 1, 2023

Primary Completion (Anticipated)

December 1, 2024

Study Completion (Anticipated)

April 1, 2025

Study Registration Dates

First Submitted

April 13, 2023

First Submitted That Met QC Criteria

April 24, 2023

First Posted (Actual)

April 26, 2023

Study Record Updates

Last Update Posted (Actual)

April 26, 2023

Last Update Submitted That Met QC Criteria

April 24, 2023

Last Verified

April 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CONvsWFO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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