TY - JOUR
T1 - The role of apoptosis in the early corneal wound healing after excimer laser keratectomy in the rat
AU - Li, Qian
AU - Ashraf, M. Farooq
AU - Bekoe, Nicoletta A.
AU - Stark, Walter J.
AU - Chan, Chi Chao
AU - O'Brien, T. P.
N1 - Funding Information:
Acknowledgement This study was supported, in part, by a grant from the Helen and Raymond Kwok research fund (Hong Kong) to the Wilmer Eye Institute. Michele Melia, M.S. of the Division of Clinical Trials and Biometry conducted the statistical analysis included in the manuscript.
PY - 2000
Y1 - 2000
N2 - Background: The potential role of apoptosis in corneal wound healing after excimer laser keratectomy was investigated in a rat model. Methods: Lewis rats underwent laser keratectomy using a 193-nm excimer laser. The central corneas were ablated in three depths: group A, epithelium; group B, superficial stroma; group C, deep stroma. Eyes were collected at 1, 12, 24, and 36 h and 1 week. Cellular markers associated with apoptosis - Fas, Fas ligand (FasL), Bcl-2, and Bax - were examined by immunohisto-chemistry. Keratocyte depletion and endothelial changes were evaluated histologically. In situ end labeling of double-stranded DNA breaks was used to demonstrate apoptosis in corneal sections. Results: Keratocyte depletion was observed in 6 (50%) of 12 rats (total from groups A, B, and C) at 12 h, 11 (73%) of 15 at 24 h, 3 (20%) of 15 at 36 h, and 2 (15%) of 13 at 1 week after laser surgery. Corneal endothelial edema was observed in the ablation zone. Expression of Fas, FasL, Bcl-2, and Bax in corneal cells showed dynamics similar to that of keratocyte depletion and endothelial changes. There was less expression of apoptotic molecules in newly generated epithelial cells and more in endothelial cells of the stromal ablation groups. Conclusions: Excimer laser keratectomy triggered apoptosis of corneal keratocytes and endothelial cells. More endothelial edema was observed in the stromal ablation than in the epithelial ablation group. The expression of apoptotic molecules coincided with the period of keratocyte depletion and regeneration and of endothelial recovery, suggesting that apoptosis is a dynamic part of corneal wound healing and remodeling after excimer laser keratectomy.
AB - Background: The potential role of apoptosis in corneal wound healing after excimer laser keratectomy was investigated in a rat model. Methods: Lewis rats underwent laser keratectomy using a 193-nm excimer laser. The central corneas were ablated in three depths: group A, epithelium; group B, superficial stroma; group C, deep stroma. Eyes were collected at 1, 12, 24, and 36 h and 1 week. Cellular markers associated with apoptosis - Fas, Fas ligand (FasL), Bcl-2, and Bax - were examined by immunohisto-chemistry. Keratocyte depletion and endothelial changes were evaluated histologically. In situ end labeling of double-stranded DNA breaks was used to demonstrate apoptosis in corneal sections. Results: Keratocyte depletion was observed in 6 (50%) of 12 rats (total from groups A, B, and C) at 12 h, 11 (73%) of 15 at 24 h, 3 (20%) of 15 at 36 h, and 2 (15%) of 13 at 1 week after laser surgery. Corneal endothelial edema was observed in the ablation zone. Expression of Fas, FasL, Bcl-2, and Bax in corneal cells showed dynamics similar to that of keratocyte depletion and endothelial changes. There was less expression of apoptotic molecules in newly generated epithelial cells and more in endothelial cells of the stromal ablation groups. Conclusions: Excimer laser keratectomy triggered apoptosis of corneal keratocytes and endothelial cells. More endothelial edema was observed in the stromal ablation than in the epithelial ablation group. The expression of apoptotic molecules coincided with the period of keratocyte depletion and regeneration and of endothelial recovery, suggesting that apoptosis is a dynamic part of corneal wound healing and remodeling after excimer laser keratectomy.
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U2 - 10.1007/s004170000182
DO - 10.1007/s004170000182
M3 - Article
C2 - 11127573
AN - SCOPUS:0033760477
SN - 0721-832X
VL - 238
SP - 853
EP - 860
JO - Graefe's Archive for Clinical and Experimental Ophthalmology
JF - Graefe's Archive for Clinical and Experimental Ophthalmology
IS - 10
ER -