The Role of Antioxidant Supplementation in Keratoconus Patients

Study Overview
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Brief Summary
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Keratoconus is the most common primary cornea ectasia, where the cornea undergoes structural changes, leading to loss of tissue integrity and vision loss. The prevalence of Keratoconus is 1:2000 in the general population. Oxidative stress has been thought to have a major effect in the disease pathogenesis of Keratoconus. In vitro studies have shown increase in metabolites related to oxidative stress in Keratoconus disease, and that Keratoconus cells undergo increased oxidative stress and tissue damage. Animal models have shown a therapeutic effect of Vitamin C (ascorbate) in corneal wound healing. Glutathione and Vitamins A, C, and E are important antioxidants in the human body. To this date, the role of systemic antioxidant supplementation in Keratoconus patients has yet to be studied. In addition, it has yet to be established as to whether there is a correlation between serum antioxidant levels, and the severity of disease in the Keratoconus patient. The investigators propose to investigate the plasma levels of antioxidants in relation to disease severity. The investigators will also investigate the role of antioxidant supplementation-consisting of parenteral Glutathione (GSH), and Vitamins A, C and E-in delaying the disease progression in Keratoconus.

Official Title
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The Role of Antioxidants in Keratoconus Patients-A Randomized Controlled Trial of Oral Supplementation of Glutathione, Vitamin A, Vitamin C and Vitamin E

Conditions
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Keratoconus

Intervention / Treatment
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* Other: Antioxidants (Vitamins A,C,E) plus GSH
* Other: Placebo
* Dietary Supplement: Centrum
* Combination Product: Dietary Sources


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants would be without illness or condition that could make follow-up, or compliance with study medication difficult. Participants may have a prior diagnosis of Keratoconus, or may be diagnosed at the initial visit. Participants should not have an eye diagnosis, other than Keratoconus, that could adversely influence the visual acuity. These participants must not have had prior surgical procedure to treat Keratoconus, including collagen cross-linking, Intacs ring segments, or corneal transplantation. Exclusion Criteria: would exclude smokers and former-smokers.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo with Dietary Sources of Vitamins<br>Persons assigned to placebo, who obtain Vitamins A, C, E and Glutathione from dietary sources alone, and have not been on oral RDA supplementation, in the 1 month leading up the time of enrollment and throughout the study period. | Other: Placebo<br>* Placebo pill<br>Combination Product: Dietary Sources<br>* From dietary sources of vitamins.<br>|
| Active Comparator: Antioxidants(Vitamins A,C,E) plus GSH, plus Centrum<br>Persons assigned to the study medication, and are continuing the take an oral RDA supplementation, in the form of Centrum. | Other: Antioxidants (Vitamins A,C,E) plus GSH<br>* Study medication would contain 500 milligrams of vitamin C, 400 International Units of vitamin E, and 15 milligrams of beta-carotene (the equivalent to 25,000 International Units of vitamin A).The study medication would also contain 1000mg of Glutathione (GSH).<br>Dietary Supplement: Centrum<br>* Centrum<br>|
| Active Comparator: Antioxidants (Vitamins A,C, E) plus GSH<br>Persons assigned to the study medication alone, without oral RDA supplementation in the 1 month leading up the time of enrollment and throughout the study period. | Other: Antioxidants (Vitamins A,C,E) plus GSH<br>* Study medication would contain 500 milligrams of vitamin C, 400 International Units of vitamin E, and 15 milligrams of beta-carotene (the equivalent to 25,000 International Units of vitamin A).The study medication would also contain 1000mg of Glutathione (GSH).<br>|
| Active Comparator: Placebo plus Centrum<br>Persons assigned to placebo, who have been on oral RDA supplementation, who would continue to do so throughout the study. | Other: Placebo<br>* Placebo pill<br>Dietary Supplement: Centrum<br>* Centrum<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Visual Acuity Measured by Snellen Chart |  | Baseline to 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in cornea thickness as measured by video keratography |  | Baseline to 24 months | 
| Plasma level of Vitamin A | Blood draws to look at plasma level of Vitamin A | Baseline to 24 months | 
| Plasma level of Vitamin C | Blood draws to look at plasma level of Vitamin C | Baseline to 24 months | 
| Plasma level of Vitamin E | Blood draws to look at plasma level of Vitamin E | Baseline to 24 months | 
| Plasma level of Glutathione (GSH) | Blood draws to look at plasma level of GSH | Baseline to 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Keratoconus progression, Vitamins and keratoconus, Vitamin supplementation