Topical Insulin Versus Autologous Serum After Corneal Surgeries

Study Overview
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Brief Summary
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The aim of the study is to test whether use of topical insulin or autologous serum eye-drops can promote corneal epithelial healing following photorefractive keratectomy (PRK).

Detailed Description
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Topical insulin has been proved recently to enhance the corneal reepithelization rate and manage neurotrophic corneal ulcers unresponsive to conventional treatments. However, its effectiveness on corneal epithelial wound healing in patients who received photorefractive keratectomy (PRK) has not been reported. In this study, we plan to perform a prospective non-randomized study to determine the efficacy and safety of topical insulin as a primary treatment for a corneal epithelial defect in patients undergoing the PRK and compare that to autologous serum eye drops. The study eye will receive either the insulin or the serum eye drops, in addition to the conventional treatment, while the control eye will have the standard treatment. For each eligible candidate, the eye with a higher depth of ablation will be the study eye. If even ablation depth in both eyes, the right eye will be selected. The conventional postoperative eye drops include topical moxifloxacin 0.5% (Vigamox; Alcon Laboratories) four times per day, artificial tears (Systane Ultra; Alcon) every two hours, Dexamethasone 0.1% (Maxidex; Alcon Laboratories) four times daily for one month followed by fluorometholone 0.1% (Efemyo; OrchidiaLaboratories) four times daily for another two to four weeks depending on refraction and haze level. In study eyes, the patients receive either topical insulin eye drops or autologous serum in addition to conventional postoperative eye drops until complete epithelial healing. The duration for the corneal surface to completely re-epithelize, the grade of postoperative corneal haze, the incidence of corneal complications due to delayed surface re-epithelization (e.g. infectious corneal ulcer, corneal melting, sterile corneal ulcer, corneal neovascularization), and the distant corrected visual acuity will be compared between these three groups.

Official Title
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Topical Insulin Versus Autologous Serum and Enhanced Corneal Epithelial Healing After Keratorefractive Surgeries

Conditions
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Corneal Epithelial Wound

Intervention / Treatment
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* Drug: Insulin
* Drug: autologous serum (AS)
* Drug: conventional


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: stable refraction of at least one year, normal corneal topography, and a minimum central corneal thickness of 500 μm. Exclusion Criteria: unstable refraction, dry eye, blepharitis, corneal disease, glaucoma, systemic diseases including infectious and collagen vascular diseases, diabetes, and topographical evidence of keratoconus.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: conventional<br>Corneal epithelial wound healing in patients who received photorefractive keratectomy (PRK) treated only with conventional postoperative eye drops. | Drug: conventional<br>* Topical moxifloxacin 0.5% (Vigamox; Alcon Laboratories) four times per day, artificial tears (Systane ultra; Alcon) every two hours, Dexamethasone 0.1% (Maxidex; Alcon Laboratories) four times daily for one month then fluorometholone 0.1% (Efemyo; Orchidia Laboratories) four times daily for another two to four weeks depending on refraction and haze level.<br>|
| Active Comparator: Insulin<br>Corneal epithelial wound healing in patients who received photorefractive keratectomy (PRK) treated with topical insulin and conventional postoperative eye drops. | Drug: Insulin<br>* Topical insulin drops will be prepared by diluting 1 unit of rapid-acting insulin per 1 mL of an artificial tear with a propylene glycol base. Drops will be preserved at low temperature (2ºC) and applied four times a day.<br>Drug: conventional<br>* Topical moxifloxacin 0.5% (Vigamox; Alcon Laboratories) four times per day, artificial tears (Systane ultra; Alcon) every two hours, Dexamethasone 0.1% (Maxidex; Alcon Laboratories) four times daily for one month then fluorometholone 0.1% (Efemyo; Orchidia Laboratories) four times daily for another two to four weeks depending on refraction and haze level.<br>|
| Active Comparator: Autologous serum eye drops<br>Corneal epithelial wound healing in patients who received photorefractive keratectomy (PRK) treated with Autologous serum eye and conventional postoperative eye drops. | Drug: autologous serum (AS)<br>* Whole blood (20 ml) wll be procured by venipuncture, centrifuged at 1,500 revolutions per minute (relative centrifugal force of 25.15 × g) for 10 minutes. AS drops will be carefully prepared under a laminar airflow cabinet, and diluted with artificial tears (Systane ultra; Alcon) to 20%. AS drops will be prepared on the day of surgery and patients will be asked to keep AS drops refrigerated at about 4C.<br>Drug: conventional<br>* Topical moxifloxacin 0.5% (Vigamox; Alcon Laboratories) four times per day, artificial tears (Systane ultra; Alcon) every two hours, Dexamethasone 0.1% (Maxidex; Alcon Laboratories) four times daily for one month then fluorometholone 0.1% (Efemyo; Orchidia Laboratories) four times daily for another two to four weeks depending on refraction and haze level.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration for the corneal surface to completely re-epithelialize. |  | up to 6 weeks | 
| Grade of postoperative corneal haze | 0, completely clear cornea; +0.5, barely visible corneal opacity; +1, reticular subepithelial opacities not interfering with visibility of fine iris details; +2, punctate or coalesced subepithelial opacities with mild obscuration of iris details; +3, confluent subepithelial opacities with moderate obscuration of the iris and lens; and +4, dense opacities with complete opacification of the stroma. | 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of corneal complications due to delayed surface re-epithelization (e.g. infectious corneal ulcer, sterile corneal ulcer, corneal melting, corneal neovascularization). |  | 6 weeks | 
| Best-corrected Visual Acuity improvement (Snellen, decimal) |  | Before and after treatment completion, assessed up to 6 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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PRK, lasik, topical insulin, autologous serum