Objective: To study the pathological changes after indirect optic nerve injury.
Methods: Animal models (72 rabbits, 144 eyes) for intracanalicular optic nerve injury was developed by keeping the optic canal intact. The pathological changes of optic nerve were observed under light microscope and transmission electron microscope and the number of myelinated axons was enumerated by computer-aided image analyzer. The data were analyzed by using variance of SAS software.
Results: The model contributed much valuable information regarding nerve edema, loss of myelin, myelin regeneration and changes of axons. The edematous area in the optic nerve injury was reduced (P < 0.01) by treating with prednisone. The counted number of myelinated fibers showed more in the group treated by prednisone than that in the group without treatment.
Conclusions: Significant changes of optic nerve after indirect injury are edema, demyelination and the change of axon amount. The effects of prednisone on reducing these pathological changes are demonstrated in this study.