Endothelial cell surface-associated keratan sulfate after excimer laser photoablation of the anterior rabbit cornea.
OBJECTIVE
The expression of keratan sulfate on the surfaces of corneal endothelial cells is altered when the cells are responding to injury. The purpose of this study was to investigate whether excimer laser surgery affected corneal endothelial cells and the levels of keratan sulfate associated with them.


METHODS
We performed 14 bilateral, transepithelial phototherapeutic keratectomies in rabbits using a Nidek EC-5000 excimer laser. Ablations were 6 mm in diameter and 50 microm, 150 microm, or 240 microm deep. At various times following surgery the endothelium was immunolabeled for keratan sulfate and examined by scanning electron microscopy. Four untreated corneas were also examined.


RESULTS
Three days after surgery, endothelial cells were not flat but were rounded or domed, a finding that was more pronounced after deeper ablations. No rounded cells, however, were seen at post-operative day 12. Keratan sulfate immunolabel was elevated on endothelial cells 3 days after surgery. By postoperative day 36, its expression was normal under the 50-microm ablations, but remained elevated under one of two 240-microm ablations.


CONCLUSIONS
Corneal endothelial cells take on a rounded appearance in the early stages after excimer laser photoablations in rabbits, especially after deeper ablations. The apical surface of the endothelium also transiently expresses elevated levels of cell surface-associated keratan sulfate following surgery. These changes appear to be responses to some aspect of the surgery, and may have physiological implications.
Quantock
A J
AJ
Department of Ophthalmology, Kyoto Prefectural University of Medicine, Japan.
Bairaktaris
G
G
Fullwood
N J
NJ
Ito
M
M
Suzuki
T
T
Kinoshita
S
S
D000818:Animals; D003315:Cornea / Q000378:metabolism / Q000601:surgery*; D004728:Endothelium, Corneal / Q000378:metabolism* / Q000601:surgery / Q000648:ultrastructure; D005500:Follow-Up Studies; D007632:Keratan Sulfate / Q000378:metabolism*; D054018:Lasers, Excimer; D008855:Microscopy, Electron, Scanning; D016253:Microscopy, Immunoelectron; D018903:Photorefractive Keratectomy; D011817:Rabbits
D007632:Keratan Sulfate