Live or Let Die: Epithelial Flap Vitality and Keratocyte Proliferation Following LASEK and Epi-LASIK in Human Donor and Porcine Eyes.
OBJECTIVE
To determine the relationship between epithelial flap vitality and stromal keratocyte proliferation following two epithelial refractive techniques: epi-LASIK and laser epithelial keratomileusis (LASEK).


METHODS
Human corneas were maintained in organ culture and underwent standard -6.00-diopter ablation. Rates of stromal keratocyte proliferation were detected 1 week postoperative using a Ki67 antibody specific to proliferating cells. Images were captured with a laser scanning confocal microscope and analyzed by a masked observer. Epithelial flap vitality was determined with propidium iodide using fresh porcine corneas. Epithelial flaps were created with Gebauer Epikeratome epi-LASIK or alcohol-assisted LASEK method. Flaps treated with 100% alcohol and uninjured corneas were used as controls.


RESULTS
The number of proliferating keratocytes was greatest at 1 week in the epi-LASIK corneas (P<.001). Cell vitality was greatest in the epi-LASIK flaps and declined in the LASEK and 100% alcohol flaps (P<.001).


CONCLUSIONS
In this in vitro setting, epi-LASIK results in an epithelial flap with significantly more live cells. There is also a greater number of proliferating stromal cells following epi-LASIK at 1 week. Based on these in vitro observations, epi-LASIK may result in greater levels of haze compared to LASEK.
Angunawela
Romesh I
RI
Winkler von Mohrenfels
Christoph
C
Kumar
Anupma
A
O'Brart
David P S
DP
Marshall
John
J
D003315:Cornea / Q000601:surgery; D006801:Humans; D049008:Keratectomy, Subepithelial, Laser-Assisted; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use; D009216:Myopia / Q000601:surgery; D013524:Surgical Flaps