Corneal Crosslinking in Patients With Keratoconus and Post-Refractive Ectasia

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the effectiveness of using riboflavin and UV light to treat progressive keratoconus or post-refractive corneal ectasia.

Detailed Description
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The primary objective of this study is to evaluate two riboflavin-dosing regimens for corneal collagen cross-linking to slow the progressive changes in corneal curvature in eyes with progressive keratoconus or post-refractive ectasia.

Official Title
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Evaluation of Two Riboflavin Dosing Regimens for Corneal Collagen Cross-Linking in Eyes With Progressive Keratoconus or Ectasia

Conditions
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Keratoconus, Post-Refractive Ectasia

Intervention / Treatment
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* Drug: Riboflavin
* Device: UVX light


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 10 years of age or older Having documented ectasia on topography or tomography after previous refractive surgery OR progressive keratoconus defined as one or more of the following changes over a period of 36 months or less before randomization: An increase of ≥ 1.00 D in the steepest keratometry value (or sim K) An increase of ≥ 1.00 D in regular astigmatism evaluated by subjective manifest refraction A myopic shift (decrease in the spherical equivalent) of ≥ 0.50 D on subjective manifest refraction Documented decrease in visual acuity associated with irregular astigmatism and topographic features of ectasia. Subjects with keratoconus diagnosis only: a. Axial topography consistent with keratoconus b. Presence of central or inferior steepening on the Pentacam map. c. Presence of one or more slit lamp findings associated with keratoconus, such as: i. Fleischer ring ii. Vogt striae iii. Corneal thinning iv. Corneal scarring Contact Lens Wearers Only: Removal of contact lenses for the required period of time prior to the screening refraction: Contact Lens Type Minimum Discontinuation Time Soft 3 Days Soft Extended Wear 1 Week Soft Toric 2 Weeks Rigid gas permeable 2 Weeks Signed written informed consent Exclusion Criteria: 1. Any keratoconus patient over 21 years of age without evidence of progression of his corneal deformity. 2. Patients with excessively thin corneas. 3. Previous ocular condition in the eyes 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 proposed treatment zone 4. A history of chemical injury or delayed epithelial healing in the eye(s) to be treated. 5. A known sensitivity to treatment medications. 6. Patients with a current condition that, in the treating physician's opinion, would interfere with or prolong epithelial healing. 7. Pregnancy (including plan to become pregnant) or lactation during the course of the study

Ages Eligible for Study
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Minimum Age: 10 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Riboflavin 0.1% eyedrops every 5 minutes<br>The eye will be irradiated for 30 minutes with UVX light, during which time instillation of riboflavin will continue (1 drop every 5 minutes for this arm). | Drug: Riboflavin<br>* Riboflavin 0.1% eye drops are applied before and during irradiation of the cornea.<br>Device: UVX light<br>* UVX 365 nm wavelength light source is applied with continued application of riboflavin.<br>|
| Active Comparator: Riboflavin 0.1% eyedrops every 2 minutes<br>The eye will be irradiated for 30 minutes with UVX light, during which time instillation of riboflavin will continue (1 drop every 2 minutes for this arm). | Drug: Riboflavin<br>* Riboflavin 0.1% eye drops are applied before and during irradiation of the cornea.<br>Device: UVX light<br>* UVX 365 nm wavelength light source is applied with continued application of riboflavin.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Maximum Keratometry From Baseline to 6 Months After Treatment | Change in maximum keratometry (Kmax) between baseline and 6 months after treatment, measured by corneal tomography. | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pachymetry | Minimum corneal thickness measured by corneal tomography | 6 months | 
| Corrected Distance Visual Acuity (CDVA) | Corrected distance visual acuity (CDVA) reported in logarithm of the minimum angle of resolution (logMAR). Lower numbers represent better vision; 0.0 corresponds to 20/20 vision. Each increase of 0.1 on the logMAR scale corresponds to one less line read on the eye chart. | 6 months | 
| Uncorrected Distance Visual Acuity (UDVA) | Uncorrected distance visual acuity reported in logarithm of the minimum angle of resolution units. Lower numbers represent better vision; 0.0 corresponds to 20/20 vision without any type of correction such as glasses. Each increase of 0.1 on the logMAR scale corresponds to one less line read on the eye chart. | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Keratoconus, Ectasia, cross linking, collagen cross linking