Comparative Study To The Haze Forming Experiment After Epi-LASIK And Flap-free Epi-LASIK Operation To Rabbits

Objective: Observe and compare the cornea epidermis haze develop-ment after Epi-LASIK and Flap-free Epi-LASIK operation, and preliminary probe into its pathogenesis.Methods: 21 heathy New Zealand big-eared rabbits, 18 of them are performed Flap-free Epi-LASIK and Epi-LASIK operation respectively on each eye. Then do -10D cutting with VISX20/20 . The other 3 rabbits are use to be reference. Classify and evaluate the haze formed of each group under slit lampapartly one month, two months and three months later of the two operations. Select 6 eyes from each group at random. Then take their corneal tissue and halve them. One half is used to histology examination and the another half is freezed and used to biology examination. The first part: Take the corneal tissue and make use of TEM , RT-PCR and IHC etc. to observe the correlative index. The second part: Use IHC method to ex-amine expression of TGF-βand b-FGF.Compare and probe into its function during the haze forming and developing after the two kinds of operations.Results: At each time point Haze's classification, expression ofα-SMA and collagen typeⅢmRNA show that there is no statistics meaning of in-terclass discrepancy after Flap-free Epi-LASIK and Epi-LASIK operation. TEM reuslt shows that epithelium tissue and basement membrane are almost intact at each time point. stroma cell in the first and third month are normal and collagen arranges orderly; In the second month, stroma cel are active obviously but collagen arranges disorderly.RT-PCR examine shows that there is no obvious statistics discrepancy of expression of collagen typeⅢmRNA after the two operation, Epi-LASIK and Flap-free Epi-LASIK at each time point; development expression of collagen typeⅢmRNA presents rising first and falling later, and reaching its height two month later of operation. IHC examine shows that there is no obvious statistics discrepancy of expression of TGF-β2,b-FGF after the two operation, Epi-LASIK and Flap-free Epi-LASIK at each time point; expression of TGF-β2 presents falling gradually; But expression of b-FGF presents rising gradually with time prolonging.Conclusion: The haze forms and develops similarly after two kinds of operation to rabbit, Epi-LASIK and Flap-free Epi-LASIK. There is no bo-vious discrepancy of the key factor TGF-β2 and b-FGF's expression which affect Haze's forming and development after operations.