Morphology of the stromal surface and endothelium using two different microkeratomes.
OBJECTIVE
To compare stromal surface and endothelial morphology after keratectomies and after laser in situ keratomileusis (LASIK), using two different microkeratomes.


METHODS
Keratectomies (160-microm and 400-microm) were performed on 82 enucleated porcine eyes using the Chiron Automated Corneal Shaper (52 eyes) and the Microtech Turbokeratome (30 eyes). LASIK procedures of -9.00 D, -27.00 D, and -36.00 D were performed with a Schwind excimer laser. The corneas were immediately fixed in glutaraldehyde or stained with alizarin red and trypan. Scanning electron microscopy was then performed.


RESULTS
All keratectomies performed with the Chiron microkeratome displayed a relatively smooth surface. The quality of the keratectomies with the manually advanced Microtech microkeratome was variable, with a high incidence (4 of 9) of incomplete cuts and irregular surfaces. In the eyes in which the stromal laser ablation was performed, a thin layer of condensed stroma (pseudomembrane formation) was seen. Vital staining did not indicate endothelial damage.


CONCLUSIONS
The surface morphology was unacceptable for one of the microkeratomes tested. Keratectomies of 160 to 400 microm and LASIK up to -36.00 D did not acutely alter endothelial morphology in porcine eyes.
Frueh
B E
BE
Department of Ophthalmology, University of Bern, Switzerland.
Eggli
P
P
Böhnke
M
M
D000818:Animals; D003319:Corneal Stroma / Q000601:surgery / Q000648:ultrastructure*; D004728:Endothelium, Corneal / Q000601:surgery / Q000648:ultrastructure*; D020731:Keratomileusis, Laser In Situ / Q000295:instrumentation*; D008855:Microscopy, Electron, Scanning; D013524:Surgical Flaps; D013552:Swine