Epi-keratoplasty Versus Collagen Cross-Linking in Progressive Keratoconus

Study Overview
=================
Brief Summary
-----------------
Epi-keratoplasty Versus Collagen Cross-Linking in Progressive Keratoconus

Detailed Description
-----------------
Keratoconus is a bilateral corneal ecstatic disease which is not uncommon and always behaves progressively and results in visual impairment by inducing irregular astigmatism and corneal opacities. Collagen Cross-Linking (CXL) is widely used in progressive keratoconus. The cornea is soaked with a riboflavin solution and then being exposed to ultraviolet-A radiation. The performance creates links between collagen fibrils in order to rigidify the corneal stroma and slow down the progression of keratoconus. However, the effectiveness is not satisfied and accompanied with risks of side effects and serious complications, such as pain for the first two post-operative days, temporary loss of visual acuity during the first three months, infection and stromal opacity due to corneal scarring. Epi-keratoplasty is a reversible technique in which a corneal graft is transplanted on the recipients' eye with only removal of the epithelium of the receptor cornea. The procedure was assisted by femtosecond laser which allows precisely and neatly cutting. The graft strengths the whole host corneal rigidity and roughness and therefore renders the progression of keratoconus.

Official Title
-----------------
Femtosecond Laser Assisted Epi-keratoplasty Versus Collagen Cross-Linking in Progressive Keratoconus

Conditions
-----------------
Progressive Keratoconus

Intervention / Treatment
-----------------
* Procedure: Epi-keratoplasty
* Procedure: Collagen Cross-Linking
* Device: Femtosecond laser


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: diagnosis of Keratoconus Age ≥ 18 years old Corneal thickness ≥ 400 µm Progressive stage 1 to 3 keratoconus (Krumeich classification) Exclusion Criteria: Corneal thickness < 400µm Concomitant corneal disease History of corneal surgery

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Epi-keratoplasty Group<br>Epi-keratoplasty Group: Reversible keratoplasty performed with only the removal of corneal epithelium of the host cornea. A donor graft is transplanted on the recipients' eye locating on the Bowman's layer. | Procedure: Epi-keratoplasty<br>* Femtosecond laser assisted Epi-keratoplasty<br>Device: Femtosecond laser<br>* Use in the epic-keratoplasty surgery<br>|
| Active Comparator: Collagen Cross-Linking Group<br>Collagen Cross-Linking: Corneal epithelium is mechanically removed. Then, a solution of riboflavin is instilled each minute for 30 minutes. Corneas are irradiated by a UVA light for 3mW/cm2 during 30 minutes | Procedure: Collagen Cross-Linking<br>* Collagen Cross-Linking: Standard procedure, which is descriptor bellows: Corneal epithelium is mechanically removed. Then, a solution of riboflavin is instilled each minute for 30 minutes. Corneas are irradiated by a UVA light for 3mW/cm2 during 30 minutes<br>* Other names: CCL;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes of Spherical equivalent |  | 01012016 01012018: preoperatively, postoperatively 2 weeks, 1,2,3,6,12 months, 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| maximum keratometry (K-max) derived from computerized video keratography |  | 01012016 01012018: preoperatively, postoperatively 2 weeks, 1,2,3,6,12 months, 2 years | 
| minimum keratometry | also from computerized video keratography, the opposite description of K-max | 01012016 01012018: preoperatively, postoperatively 2 weeks, 1,2,3,6,12 months, 2 years | 
| Visual acuity |  | 01012016 01012018: preoperatively, postoperatively 2 weeks, 1,2,3,6,12 months, 2 years | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Keratoconus