Purpose. To determine the changes and potential role of apoptotic cell makers after excimer keratectomy. Method?. A 3 mm central corneal ablation was performed in Lewis rats using the VISX 20/20 excimer laser. Treatment depths were divided into 3 groups: Group A40 urn central epithelial ablation, Group B- 40 urn epithelial ablation and 20 urn stromal ablation, Group C- 40 urn epithelial ablation and 40 urn stromal ablation. Animals were then sacrificed at 1 hr, 24 hrs, 36 hrs, and 1 week. Eyes were harvested and processed for immunohistochemistry or histology. Cellular markers associated with apoptosis: FAS, FAS ligand (FasL), Bcl-2, and Bax were detected on frozen sections by immunohistochemistry using a graded scale. Results. Fas, FasL, bcl-2 and bax were expressed in all of the control corneas mostly in the epithelium. Fas and FasL expression in the epithelium was gradually decreased from 24 hrs to one week after surgery. The grading was 3+ at baseline, 1.5 at 24 and 36hrs, and decreased to 0.5 at one week. Expression of Fas/FasL was also observed in a few keratocytes in the stroma. No change was found in the epithelium for bcl-2 and bax. However, Bcl-2 expression occured in keratocytes after Ihr, increased to 2-3+ at 24 and 36 hrs, and disappeared at one week. Bax expression was observed at 24 and 36 hrs in stroma. No significant difference was found among the 3 groups. Cpqclujaojl, Apototic makers have changed after excimer laser keratectomy. The expression pattern of apoptosis markers was more closely associated with the time period after the surgery. The decreased Fas/FasL expression may increase the risk of keratitis. The appearance of the survival signal, Bcl-2, and the death inducing signal, Bax, may play a role in stromal remodelling after excimer keratectomy.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience