Topography Versus Non-Topography-Guided PRK With CXL in Keratoconus (keratoconus)

April 10, 2022 updated by: farinaz doroodgar, Shahid Beheshti University

Topography Versus Non-Topography-Guided Photorefractive Keratectomy With Corneal Cross-Linking Variations in Keratoconus

To our knowledge, this study is one of the first to compare the visual results of non-topography-guided and topography-guided photorefractive keratectomy (PRK) applying sequential and simultaneous corneal cross-linking (CXL) treatment for keratoconus. Considering recent advances in cross-linking and imaging in keratoconus, the outcomes of this study can lead us to several non-invasive algorithm management options.

Study Overview

Status

Enrolling by invitation

Conditions

Detailed Description

Interventional and comparative prospective study: Sixty-nine eyes (38 patients) suffering from keratoconus (stages 1-2 Amsler-Krumeich classification) were divided into four groups. The four groups underwent topography- and non-topography-guided PRK with sequential and simultaneous CXL. The main outcome measures were pre- and postoperative uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (CDVA), manifest refraction, contrast sensitivity, and keratometry.

Study Type

Interventional

Enrollment (Anticipated)

38

Phase

  • Not Applicable

Contacts and Locations

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

Study Locations

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

34 years to 41 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion criteria

  • age 34 (range from 34 to 41)
  • stable corneal topography and refraction for at least six months
  • estimated residual bed thickness of >410 µm

Exclusion

  • presence of macular or retinal disease,
  • dry eye
  • history of recurrent corneal erosions
  • anterior segment abnormalities
  • unstable refractive error
  • post-surgically residual stromal bed thickness of under 350 mm
  • autoimmune disease
  • collagen vascular disease
  • immunosuppressive therapy or current use of systemic corticosteroids
  • diabetes mellitus
  • pregnancy
  • lactation

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

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Photorefractive keratectomy in mile keratoconus
Photorefractive keratectomy in mile keratoconus type of corneal surface ablation in for correct refractive error
Topo-guided photorefractive keratectomy will be performed using an excimer laser (Allegretto Wave Topolyzer, Alcon, Inc.) with a 6 mm optical area and a transition area of 2 mm in all eyes. At that point, the partial topography-guided photorefractive keratectomy laser treatment will be finished. The arrangement will be to treat 70% of the cylindrical and spherical part to not surpass 50μm of stromal expulsion. The estimation of 50μm as the most extreme removal depth recommended by Kanellopoulos in Athens protocol will be chosen
Other Names:
  • Advance surface abelation in mild keratoconus

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
visual acuity
Time Frame: 3 months
Visual acuity (VA) commonly refers to the clarity of vision
3 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Aberrometry properties by iTrace Ray-tracing aberrometry
Time Frame: 3 year
Optical aberrations are a major cause for poor quality of vision. It occurs when light from one point, after transmission through an optical system, does not converge to or diverge from a single point. Any deviation of the optical system from paraxial optics results in aberrations. In the eye, the various refracting surfaces like tear film, cornea and lens are primarily responsible for inducing ocular aberrations. The difference in shape of the wave-front entering the eye and that exiting the eye defines the type of aberration. The ocular aberrations are classified into lower order aberration (LOA) (zero order- piston; first order- horizontal and vertical tilt; second order- spherical defocus and astigmatism) and higher order aberrations (HOA) (third order - coma and trefoil; fourth order - quatrefoil, secondary astigmatism and spherical aberrations; fifth order - pentafoil; sixth order - hexafoil).
3 year

Collaborators and Investigators

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

Investigators

  • Study Chair: Jorge Alio, MD,PhD, Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain

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 (Actual)

March 30, 2017

Primary Completion (Anticipated)

September 30, 2022

Study Completion (Anticipated)

December 15, 2023

Study Registration Dates

First Submitted

March 25, 2019

First Submitted That Met QC Criteria

March 25, 2019

First Posted (Actual)

March 26, 2019

Study Record Updates

Last Update Posted (Actual)

April 18, 2022

Last Update Submitted That Met QC Criteria

April 10, 2022

Last Verified

January 1, 2022

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ShaheidBU

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.

Clinical Trials on Keratoconus

Clinical Trials on Photorefractive keratectomy in mile keratoconus

3
Subscribe