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Updated: Oct 18, 2026
Ex Vivo Corneal Organ Culture Model for Wound Healing Studies
Published on: February 15, 2019
Effect of corticosteroids on rabbits corneal keratocytes after photorefractive keratectomy
X You1, J P Bergmanson, X M Zheng
1University of Houston, College of Optometry 77204-6052, USA.
Background:
To determine the corticosteroid effect on the activity and repopulation of keratocytes after photorefractive keratectomy (PRK).
Methods:
A 193-nm excimer laser (VISX Twenty/Twenty) created a central ablation depth of 22 microns (diameter:5 nm) on 22 corneas of 16 albino rabbits. Two ablated eyes were examined 6 hours following PRK. Twelve eyes received no postoperative corticosteroids and eight were treated with topical fluoromethalone for 3 months. Corneas were examined 1, 3, 6, and 12 months after PRK by immunofluorescence and transmission electron microscopy.
Results:
Corticosteroids reduced haze (p=0.02), but all corneas (treated or untreated) cleared 6 months after PRK. Keratocytes were absent from the anterior 100 microns of the stroma 6 hours after PRK. However, the number and activity of keratocytes were significantly greater in this area in untreated corneas at 1 month and then gradually decreased. By 6 and 12 months, the number of keratocytes approached controls. Treated corneas had fewer keratocytes than either controls or untreated eyes (p<0.01) and by 3 months, a subepithelial acellular zone of 30 to 50 microns thickness appeared and persisted until at last 12 months after PRK.
Conclusions:
Corticosteroids have a transient effect in reducing haze and seem to inhibit keratocyte movement, leading to an acellular subepithelial region beneath the ablated area.
