Abstract
Purpose: :
To evaluate the early effects of a sutureless cryopreserved amniotic membrane graft (ProKeraTM, Bio-Tissue, Inc. Miami, FL) on corneal wound healing after PRK in terms of epithelial defect area (EDA) and mean time to re-epithelialization (RE).
Methods: :
This was a prospective, open-label, non-randomized, control trial of 29 subjects undergoing PRK at the Walter Reed Center for Refractive Surgery. A 20% ethanol solution was used to create a standard 9.0 mm epithelial defect followed by photoablation with Wavelight ALLEGRETO WAVE Eye-Q 400 MHz laser platform (Wavelight AG, Erlangen, Germany). After surgery, a high oxygen transmissible bandage contact lens (BCL) was applied on the dominant eye and ProKera on the non-dominant eye. Postop regimen was otherwise identical for both eyes. Patients were divided into 3 groups based on duration of ProKera: Group 1: ProKera until complete RE (n=9), Group 2: ProK removed on postoperative day (POD) 3 (n=15) and Group 3: ProKera removed on POD 1 (n=5). A BCL was inserted if there was a defect upon ProKera removal. Patients were seen daily after surgery until RE was documented in both eyes. Major outcome measures were EDA and mean time to RE. Wilcoxon signed-rank test was used to compare ProKera to BCL and p<0.05 was considered significant.
Results: :
The EDA in ProKera eyes was significantly smaller when compared to BCL eyes on POD 1 in Group 1 (43.06mm2 vs. 56.79 mm2; p=0.03) and Group 2 (47.45mm2 vs. 56.6 mm2; p=0.05) but not in Group 3 (48.00mm2 vs. 48.40mm2; p=1.0). The EDA measured in ProKera eyes and BCL eyes on POD 2-5 post-surgery were not significantly different in any group. Time to RE measured in days was not significantly different between the ProKera and BCL eyes in any Group 1: 4.6 vs. 4.1, p=0.41; Group 2: 4.8 vs. 3.9, p= 0.11; Group 3: 3.4 vs. 3.2, p= 0.32. ProKera was reasonably well-tolerated with few significant adverse effects.
Conclusions: :
ProKera promoted corneal RE on day 1 post PRK but was not superior over BCL in hastening complete RE of the cornea. Its effect on corneal clarity and quality of vision are still under investigation. The role of ProKera in modulating wound healing after PRK remains speculative.
Clinical Trial: :
www.clinicaltrials.gov NCT00915759
Keywords: cornea: epithelium • wound healing • refractive surgery: PRK