Abstract
Purpose: :
To study whether a synthetic peptide ACT 1 facilitates corneal wound healing in treated eyes compared to controls using a rat cornea burn model
Methods: :
Adult male Sprague-Dawley rats ( 250-280g) were anesthetized and the central cornea was treated with 20% ethanol for 30 seconds using a 3-mm marker placed on the corneal surface. The cornea was then thoroughly rinsed with saline and the loosened epithelial layer was removed using a detaching spatula. Rats were divided into three groups (6-8 animals per group): Group 1, no peptide treated rats; Group 2, rats treated with a control peptide (60uM, two drops, about 100ul) per eye at 0, and 24 hours after corneal surgery, and Group 3, rats treated with ACT 1 peptide (100uM, two drops, about 100ul) per eye at 0, and 24 hours. Corneal wound area was determined by administering 0.25% fluorescein sodium eye drops and digitally capturing the cornea under a fluorescent stereomicroscope at 0, 24, 48, 72 hours. Measurements of the fluorescein area were computed using Image J.
Results: :
Initial corneal wound area as determined by fluorescein labeling at 0 hours: for untreated, control peptide and ACT1-treated rats was 9.7±0.3 (pixels), 9.7± 1.3 and 9.8 ±0.6 respectively. At 24 hours, ACT1 corneal wound areas were less than 13 % of initial wound dimensions with a mean area of 1.3±0.4. By contrast, untreated and control peptide-treated wound areas were significantly larger than ACT1 wounds (p<0.01 in comparison to both controls) at 32-34 % of the initial wound area; measuring 3.3 ±0.4 and 3.1± 0.3, respectively. Closure was nearly complete for all three groups at 48 and 72 hours and thus no significant difference in area could be determined between groups at these stages.
Conclusions: :
ACT1 enhances corneal wound healing in a rat burn model, at least over the initial 24 hours following injury. Further research is ongoing and may lead to therapies for aiding epithelial healing, visual recovery, and treatment complications associated with laser subepithelial keratomileusis (LASEK)
Keywords: wound healing • cornea: epithelium • refractive surgery: LASIK