Abstract:

Objective  To evaluate the protective effect of basic fibroblast growth factor on optic nerve axons in high intraocular pressure of rabbits. Methods  Of the 22 rabbits (44 eyes), 2 rabbits (4 eyes) were  the  normal control group without receiving any injection. Carbomer was randomly injected into the other 20 rabbits′ (40 eyes) anterior chambers to make high intraocular pressure (IOP) models. 50μL of bFGF (2000U) was injected into one vitreous chamber of each rabbit randomly (bFGF therapy eyes), and the same volume of PBS into the other vitreous chambers (surgery control eyes) when making high IOP models and on days 7, 14 and 21 after it.  The optic disc of the ocular fundus, cyathus/disc area ratio, number and morphology of optic nerve axons were observed in each period. Ultrastructural changes of optic nerve axons were observed on the 28th day. Results  The optic disc became pale, umbilication became deep and blood vessels became curved on the 14th day, and the optic disc obviously changed on the 21st day in the surgery control eyes. C/DAR changes in bFGF therapy eyes were less than those in surgery control eyes(P＜0.05) on the 14th day. The number of optic nerve fibers in bFGF therapy eyes was more than that in surgery control eyes (P＜0.01). Electron microscope examination showed that the arrangement of axons was disordered and the myelinic membrane denatured and apoptosis was frequently  in surgery control eyes, and that the structure of axons was approximately normal in bFGF therapy eyes on the 28th day. Conclusion  In high intraocular pressure animal models, bFGF can protect the optic nerve axons.

Key words: Basic fibroblast growth factor; Chronic high intraocular pressure; Optic nerve; Axon; Rabbits