Gamma-Irradiated Corneal Inlay for Keratoconus

Study Overview
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Brief Summary
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Study objective is to evaluate the outcomes of placing gamma-irradiated corneal tissue (VisionGraft, CorneaGen, USA) within the cornea of patients with keratoconus, a procedure called Corneal Tissue Addition for Keratoconus (CTAK).

Detailed Description
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Using E gamma irradiated sterilized preserved corneal tissue, shaped corneal tissue inlays are placed in a keratoconic cornea. Preserved corneal tissue is currently available commercially from CorneaGen (VisionGraft,1200 6th Ave., STe.300, Seattle, WA 98101). Such tissue is currently used in a number of eye surgical procedures. It is considered suitable for corneal surgical procedures that do not require viable corneal endothelium, as is the case for a tissue enhancement procedure in keratoconus. The goal of the current protocol to evaluate the outcomes of placing gamma-irradiated preserved tissue within the keratoconic cornea in order to enhance corneal thickness, stability, and optical conformation.

Official Title
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Use of Gamma-Irradiated Preserved Corneal Tissue to Treat Keratoconus

Conditions
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Keratoconus

Intervention / Treatment
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* Procedure: Gamma-irradiated corneal tissue inlay


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: At least 18 years of age, male or female, of any race Provide written consent and sign a HIPAA form Willingness and ability to follow all instructions and comply with schedule for follow-up visits For females: must not be pregnant Having topographic evidence of keratoconus which is graded as moderate or severe keratoconus defined as the following: Moderate Keratoconus: Axial topography consistent with keratoconus, Maximum keratometry on Pentacam greater than or equal to 51.01 D Severe Keratoconus: Axial topography consistent with keratoconus with marked areas of steepening, Maximum keratometry on Pentacam greater than or equal to 56.01 D Presence of central or inferior steepening on the Pentacam map BSCVA less than or equal to 20/25 Contact lens wearers only: remove contact lenses one week prior to the screening refraction Exclusion Criteria: Contraindications, sensitivity or known allergy to the use of the test article(s) or their components If female, be pregnant Eyes classified as either normal, atypical normal, keratoconus suspect or mild keratoconus on the severity grading scheme 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, corneal melt, corneal dystrophy, etc.) A history of delayed epithelial healing in the eye to be treated Have used an investigational drug or device within 30 days of the study or be concurrently enrolled in another investigational drug or device study within 30 days of the study

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Corneal tissue inlay<br>The treated cornea will be implanted with a thin disc of gamma-irradiated preserved corneal tissue | Procedure: Gamma-irradiated corneal tissue inlay<br>* A mid-stomal pocket will be made into the cornea with a femtosecond laser (Intralase). A small disc of gamma-irradiated preserved corneal tissue will then be placed into the pocket<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gamma-Irradiated Preserved Corneal Tissue Inlay | Change in mean keratometry on corneal topography | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gamma Irradiated Preserved Corneal Tissue Inlay | Inferior-Superior (I-S) ratio | 6 months | 
| Gamma Irradiated Preserved Corneal Tissue Inlay | Manifest refraction | 6 months | 
| Gamma Irradiated Preserved Corneal Tissue Inlay | Uncorrected distance visual acuity | 6 months | 
| Gamma Irradiated Preserved Corneal Tissue Inlay | Best spectacle corrected distance visual acuity | 6 months |