A Prospective Study of the Effect of Topical Sodium Hyaluronate Immediately Post-PKP on Time to Reepithelialization

Study Overview
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Brief Summary
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Hypothesis: 1% sodium hyaluronate (Healon), applied at end of surgery to the surface of a corneal transplant will not shorten graft reepithelialization time when compared to coating with nothing. We also wish to measure and compare visual acuity in this immediate post operative period. We also wish to assess the safety of using this agent on the epithelium post-operatively. We will recruit 50 high risk patients (see inclusion criteria) here at the University of Virginia to randomly receive nothing or sodium hyaluronate (Healon) on the ocular surface at the end of surgery, and follow time to reepithelialization of the corneal transplant grafts.

Detailed Description
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Corneal transplant is one of the most common transplant procedures, with over 32,000 recipients in the United States in 2005 and a similar number estimated in 2006. The immediate post-operative period is very important in determining the quality of the graft and often its overall chance of survival. The corneal epithelium is replaced by the recipient epithelium after transplant and this should usually take place in no more than 1 week. This reepithelialization is very important for healing, recovery of the epithelial barrier against infectious agents, and for recovery of vision through the graft. Grafts that take longer to heal can invite not only infection and hinder visual recovery, but be permanently scarred, thinned, and even perforate/fail. Thus rapid reepithelialization is crucial. This becomes even more crucial for monocular patients who need quick recovery. Currently there is no universal agent that is used to coat the surface at the end of surgery before patching. Previous animal studies have shown that sodium hyaluronate will promote rapid migration of cells as well as stimulate cell proliferation leading to rapid wound closure (1,2). In 1987 one smaller study showed that topical sodium hyaluronate (Healon) may foster improved epithelial healing but it was used intraoperatively and presented technical challenges (3). A more recent non-randomized, retrospective study found that sodium hyaluronate at the end of surgery to coat the ocular surface shortened reepithelialization time. This was in comparison to dexamethasone/oxytetracycline ointment and neomycin/dexamethasone drops, both of which hinder reepithelialization (4). To date we know of no prospective, randomized, double-blinded studies that compare the application of sodium hyaluronate versus nothing (currently the practice at UVA).

Official Title
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A Prospective Study of the Effect of Topical Sodium Hyaluronate Immediately Post-PKP on Time to Reepithelialization

Conditions
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Corneal Transplantation

Intervention / Treatment
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* Drug: sodium hyaluronate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The patients considered for enrollment must be scheduled for penetrating keratoplasty. Any high risk patient requiring penetrating keratoplasty. Criteria for high risk include one of the following: Prior failed corneal graft in the operative eye Being treated for dry eye at time of surgery Having 2 or more quadrants of corneal vascularization Having another procedure performed on same eye at time of PKP Exclusion Criteria: Does not meet one of the criteria for high risk Known hypersensitivity to hyaluronate preparations Allergic to avian proteins, feathers, or egg products Pregnant or breast feeding

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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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 |
| --- | --- |
| Experimental: 1<br>1% sodium hyaluronate (Healoon) applied at the end of surgery to the surface of the corneal transplant | Drug: sodium hyaluronate<br>* 1% sodium hyaluronate applied at the end of corneal transplant surgery. The amount will be determined on how much is necessary to cover the ocular surface.<br>* Other names: Healon;|
| No Intervention: 2<br>Nothing applied at the end of surgery | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to graft reepithelialization |  | weekly until total reepithelialization occurs | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual acuity |  | 24 hours post-op and weekly until reepithelialization occurs | 
| safety |  | 24 hours then weekly until reepithelialization occurs | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Corneal transplantation