Collagen Cross-linking for keratoconus and ectasia


Status: Active, not recruiting
Keywords: corneal crosslinking therapy , keratoconus , ectasia
IRB Number: 00058991
Specialty: Ophthalmology
Sub Specialties: Cornea

Brief Summary

The objectives of this study are to evaluate and compare the safety and efficacy of three treatment regimens for corneal collagen cross-linking performed with VibeX (Riboflavin Ophthalmic Solution) and the KXL System for reducing corneal curvature.


Principal Investigator: Mark Mifflin
Department: Ophthalmology-Services
Co Investigator: Katie Farnsworth
Co Investigator: Mark Mifflin
Co Investigator: Susan Allman

Contact Information

Name:Katie Farnsworth
Phone: 801-585-6647

Inclusion Criteria

Patients must meet all of the following criteria in order to be enrolled into the trial:

1. Be at least 12 years of age, male or female, of any race;

2. Provide written informed consent and HIPAA authorization form. Patients who are under the age of 18 will need to sign an assent form as well as having a parent or legal guardian sign parental permission form;

3. Willingness and ability to follow all instructions and comply with schedule for follow-up visits;

4. For females capable of becoming pregnant, agree to have urine pregnancy testing performed prior to randomization of the study eye and on the day of the fellow eye treatment (which occurs between the 3 to 6 month study eye visits); must not be lactating, and must agree to use a medically acceptable form of birth control for at least one week prior to the randomization visit and continue to use the method until one month after the last dose of test article. Acceptable forms for birth control are spermicide with barrier, oral contraceptive, injectable or implantable method of contraception, transdermal contraceptive, intrauterine device, or surgical sterilization of partner. For non-sexually active females, abstinence will be considered an acceptable form of birth control. Women considered capable of becoming pregnant include all females who have experienced menarche and have not experienced menopause (as defined by amenorrhea for greater than 12 consecutive months) or have not undergone successful surgical sterilization (e.g. hysterectomy, bilateral tubal ligation, or bilateral oophorectomy);

5. Best corrected visual acuity of < 80 letters on ETDRS chart;

6. Presence of central or inferior steepening on the topographic map;


Contact Lens Wearers Only: Removal of contact lenses is required for a 1 week period prior to the screening refraction.

7. Contact Lens Wearers Only: manifest refraction must be stable between two visits which occur at least 7 days apart. A stable refraction is one in which the manifest refraction spherical equivalent and the average K (Km) on the topographer taken at the first visit do not differ by more than 0.75 D from the respective measurements taken at the second exam.

Patients must meet all of the following to be enrolled in the keratoconus arm of the trial:

8. Maximum corneal curvature as measured by a Kmax value ≥ 47.00 D;

9. Having topographic evidence of keratoconus with a diagnosis of mild, moderate or severe keratoconus defined as the following:

 Mild Keratoconus

 Axial topography consistent with keratoconus

 Flat keratometry reading ≤ 51.00 D on topography map

 Moderate Keratoconus

 Axial topography consistent with keratoconus

 Flat keratometry reading ≥ 51.01 D and ≤ 56.00 D or astigmatism ≥ 8.00 D on topography map

 Severe Keratoconus is defined as:

 Axial topography consistent with keratoconus with marked areas of steepening

 Flat keratometry reading ≥ 56.01 D on topography map

Patients must meet all of the following to be enrolled in the corneal ectasia arm of the trial:

10. Having a diagnosis of corneal ectasia after refractive surgery;

11. Axial topography consistent with ectasia.



Exclusion Criteria

Patients must not meet any of the following criteria in order to be enrolled into the trial:

1. Contraindications, sensitivity or known allergy to the test article(s) or their components;

2. If female, be pregnant, nursing or planning a pregnancy or have a positive urine pregnancy test prior to the treatment of either eye or during the course of the study;

3. Corneal pachymetry that is < 375 microns prior to epithelial debridement at the thinnest point in the eye to be treated;

4. Eyes which are aphakic;

5. Eyes which are pseudophakic and do not have a UV blocking lens implanted;

6. Eyes that have the maximum corneal curvature (Kmax), as identified and measured by topography, outside of the central 5mm zone;

7. Previous ocular condition (other than refractive error) in the eye to be treated that may predispose the eye for future complications. For example:

a. History of corneal disease (e.g., herpes simplex, herpes zoster keratitis, recurrent erosion syndrome, corneal melt, corneal dystrophy, etc.)


b. Clinically significant corneal scarring in the cross-linking treatment zone that is not related to keratoconus or corneal ectasia, in the investigator’s opinion, will interfere with the cross-linking procedure;

8. A history of delayed epithelial healing in the eye(s) to be treated;

9. Patients with nystagmus or any other condition that would prevent a steady gaze during the treatment or other diagnostic tests;

10. Patients with a current condition that, in the investigator’s opinion, would interfere with or prolong epithelial healing;

11. Taking Vitamin C (ascorbic acid) supplements within 1 week of the cross-linking treatment.

12. A history of previous corneal crosslinking treatment in the eye to be treated;

13. Have used an investigational drug or device within 30 days of the study or be concurrently enrolled in another investigational drug or device trial within 30 days of the study;

14. A history of previous Limbal Relaxing Incision (LRI) procedure in the eye(s) to be treated.

15. In addition, the Investigator may exclude or discontinue any subject for any sound medical reason.

Patients must not meet any of the following criteria in order to be enrolled into the keratoconus arm of the trial:

16. Eyes classified as either normal, atypical normal, or keratoconus suspect on the severity grading scheme;

17. A history of previous corneal surgery or the insertion of Intacs in the eye(s) to be treated.