[The expression of TGF-beta1 and bFGF after LASEK and the effects of 20% ethanol exposure on corneal wound healing].

OBJECTIVE

To assess the effects of 20% ethanol used in LASEK on corneal wound healing.

METHODS

Forty-eight eyes from 24 rabbits were deepithelialized by two techniques. The epithelium were detached with either 20% ethanol (applied for 30 seconds) or mechanical scraping, then ablated was performed. The number of superficial stromal keratocytes was counted and the morphologic changes were observed. Expression of TGF-beta1 and bFGF mRNAs was detected and analyzed by reverse transcription-polymerase chain reaction and immunocytochemical methods at 1, 7, 30 and 90 days after the surgery.

RESULTS

One day after the surgery, the expression of TGF-beta1 and bFGF in the keratocytes in both treated groups was lower than that of the normal controls. Seven days after the surgery, the expression of TGF-beta1 and bFGF in both treated groups was greater than that of the normal controls (P < 0.01). The expression in the alcohol-treated group was greater than that of the surgical-treated group (P < 0.01). The expression of TGF-beta1 and bFGF reached the peak 30 days after the surgery, no significant difference was detected between the alcohol-treated and surgical-treated groups. There was no significant difference in expression level between the alcohol-treated and surgical-treated groups 3 months after the surgery; as well as between treated groups and normal group. The amount of TGF-beta1 and bFGF mRNA was positively correlated with the number of keratocytes. The correlation coefficient between TGF-beta1 and bFGF mRNA and the number of the keratocytes was 0.744 (P < 0.01) and 0.738 (P < 0.01) in the alcohol-treated group; and was 0.664 (P < 0.01) and 0.785 (P < 0.01) in the surgical-treated group, respectively.

CONCLUSIONS

The expression of TGF-beta1 and bFGF mRNA undergo a dynamic process of "decrease-increase-normal". Although ethanol has a slight toxic effect on rabbit epithelial cells, but the effects do not persist over time, therefore, it is relatively safe to use the alcohol treatment in the LASEK.