[The expression of Ki-67, TGF-beta(2) and alpha-SMA after the femtosecond laser-assisted intrastromal scanning in rabbit cornea].
OBJECTIVE
To study how the cornea would express Ki-67, TGF-beta(2) and alpha-SMA and how the cornea would heal when it is scanned intrastromally.


METHODS
Twenty New Zealand white rabbits were randomly numbered and used for the experiments. The 60 kHz Intralase femtosecond laser delivery system was used to scan 35 rabbit corneas (of these corneas, 5 right corneas were from 5 rabbits). The unoperated 5 left eyes were used as control. The laser settings were: spot/line separation, 10 microm; diameter, 8.5 mm; energy for scanning the stroma, 1.3 microJ; scanning depth, 135 microm, no edge cuts were performed. Slit lamp was used to observe the cornea at 0.5 h, 1 h, 2 h, and 3 months after surgery. On day 1, 3, 7, 30, 90 after surgery, 6 and 1 scanned corneas at each time point were taken for Western blot and immunocytochemical detection respectively to detect the expression of TNF-alpha, Ki-67, TGF-beta(2) and alpha-SMA.


RESULTS
Microbubbles were found in corneal stroma after surgery. The number of microbubbles tended to decrease significantly with time. At 2 h, the cornea turned to be transparent again. During 3-month follow-up, the cornea was always transparent and no haze appeared. Western blot analysis and immunocytochemical detection demonstrated that the expression of Ki-67 began to increase at day 1(0.0670 + or - 0.0008) and reached the peak at day 3 after surgery (0.6923 + or - 0.005). While there were significant difference with the control group at day 90 after surgery (t = 24.12, 57.22, 43.26, 39.78, 18.35;P < 0.05), a gradual decrease in expression of ki-67 could be detected from day 3 to 90. There were no significant change in the expression of TGF-beta(2) (t = 0.933, 0.856, 0.934, 0.970, 1.132) and alpha-SMA (t = 1.126, 1.235, 0.993, 1.175, 1.211) at all time points after surgery (P > 0.05).


CONCLUSIONS
After intrastromal scanning, the expression of Ki-67 increases and the keratocyte is activated and proliferated. However, due to no epithelium injured and TGF-beta(2) confined to the epithelium, the activated and proliferated keratocytes could not be transformed into myofibroblasts.
Zhang
Zhen-yong
ZY
Department of Ophthalmology, Putuo Hospital, Shanghai Chinese Traditional Medicine University, Shanghai 200062, China.
Chu
Ren-yuan
RY
Zhou
Xing-tao
XT
Zhang
Xing-ru
XR
D000199:Actins / Q000378:metabolism*; D000818:Animals; D003315:Cornea / Q000601:surgery; D003319:Corneal Stroma / Q000378:metabolism*; D005260:Female; D019394:Ki-67 Antigen / Q000378:metabolism*; D054018:Lasers, Excimer; D008297:Male; D011817:Rabbits; D053781:Transforming Growth Factor beta2 / Q000378:metabolism*
D000199:Actins; D019394:Ki-67 Antigen; D053781:Transforming Growth Factor beta2