Corneal Cross-linking and Refractive Surface Ablation in Patients With Asymmetric Corneas

October 24, 2016 updated by: Mauro Campos, Federal University of São Paulo

Two Years Follow up of Corneal Cor Cross-linking and Refractive Surface Ablation in Patients With Asymmetric Corneal Topography

The purpose of this study is to evaluate safety and efficacy of corneal cross-linking and photorefractive keratectomy for refractive correction in patients with bilateral asymmetric topography.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Corneal cross-linking (CXL) by the photosensitizer, riboflavin (vitamin B2), and ultraviolet A (UVA) light increases corneal rigidity and has been described as an effective method for stabilizing the cornea in patients with progressive keratoconus. The photochemical reaction in this procedure causes the collagen to form additional covalent connections between its fibers, which stabilizes the stromal collagen fibers, improving the collagen's structure and the cornea rigidity. It is a relatively safe procedure with low rates of complications Photorefractive keratectomy (PRK) it is a traditional technique for refractive surgery. In cases of irregular corneas or re-operation normally the favorite ablation profile chosen is the guided surgery, topography guided or wavefront guided, showing better results. This technique is also relatively safe procedure with low rates of complications. One of the most unwanted complications of this surgery and also rare is corneal ectasia.

Combining PRK and CXL is already done in patients with keratoconus and suspected keratoconus.

This combined procedure uses the principle that CXL stiffen the cornea making it possible to reduce corneal thickness with PRK without weakening corneal strength. Literature show better results, in keratoconus, with simultaneous procedures. Guedj et al performed PRK in keratoconus suspects and within 5 years he did not found any corneal ectasia.

Study Type

Interventional

Enrollment (Actual)

44

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

  • Brazil
      • Sao Paulo, Brazil, 04023-062
        • Federal University of São Paulo

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

21 years to 49 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • bilateral asymmetric topography with inferior steepening
  • corneal thickness of 440 micra at the thinnest point
  • inferior-to-superior index (I-S) between 1.0D and 1.4D
  • maximum keratometric steepness < 47.00D
  • stable refraction more than 1 year.

Exclusion Criteria:

  • forme fruste keratoconus and keratoconus
  • previous eye surgery
  • previous eye trauma
  • confirmed pregnancy

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: CXL + PRK group

Corneal cross-linking surgery is perfomed in one eye : deepithelization of the cornea and instillation of 0,1% riboflavin (ophthalmos - Brazil) for 30 minutes and UVA for irradiated for 30 minutes with ultraviolet-A of 365nm light with an irradiance of 3 mW/cm2 using Xlink (Opto - São Carlos) Photorefractive keratotomy will be perfomed in the same eye using excimer laser Ladarvision (Alcon - USA) with 0,02 % mitomicin for 30 seconds (Ophthalmos - Brasil) simultaneously with the other eye.

Both procedures will have the same post operative treatment :

gatifloxacin 0,3% 6/6h for 10 days prednisolone acetate 0,12% 6/6h por 14 days
Procedure: CXL + PRK group
Corneal cross-linking with subsequent photorefractive keratotomy after 6 months was performed in one eye
Active Comparator: PRK group

Photorefractive keratotomy will be perfomed in the fellow eye using excimer laser Ladarvision (Alcon - USA) with 0,02 % mitomicin for 30 seconds (Ophthalmos - Brasil) simultaneously with the other eye.

Both procedures will have the same post operative treatment :

gatifloxacin 0,3% 6/6h for 10 days prednisolone acetate 0,12% 6/6h por 14 days
Procedure: PRK group
Photorefractive keratotomy alone was performed in contra lateral eyes

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Refractive results - spherical equivalent in diopters
Time Frame: 30 months
30 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Biomicroscopy findings with the slit lamp
Time Frame: 30 months
30 months
Visual acuity in logMar
Time Frame: 30 months
30 months
Aberrometric Results in root mean square
Time Frame: 18 months
Only coma and spherical aberration
18 months
Topographic results in diopters
Time Frame: 30 months
we will measure the increase in diopters with time
30 months
Pachymetric results in micra
Time Frame: 30 months
30 months

Collaborators and Investigators

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

Sponsor

Federal University of São Paulo

Investigators

  • Principal Investigator: Mauro Campos, MD, Federal University of São Paulo

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

January 1, 2010

Primary Completion (Actual)

January 1, 2014

Study Completion (Actual)

January 1, 2014

Study Registration Dates

First Submitted

October 21, 2016

First Submitted That Met QC Criteria

October 21, 2016

First Posted (Estimate)

October 25, 2016

Study Record Updates

Last Update Posted (Estimate)

October 26, 2016

Last Update Submitted That Met QC Criteria

October 24, 2016

Last Verified

October 1, 2016

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 2088/88

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Yes

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 Surgical Procedure, Unspecified

Clinical Trials on CXL + PRK group

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Malta

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

3
Subscribe