Recovery And Regeneration Of The Optic Nerve Following Indirect Injury In Adult Rabbit

PURPOSES Approximately 5% of all patients with closed head trauma manifest an indirect injury to the optic nerve. Visual loss due to optic nerve injury constitutes a therapeutic challenge for the clinician. It is important to study the morphology after injury, which might offer some information for the treatment of optic nerve injury.METHODS 1 In order to study the recovery of visual response, including pupils direct light response and visual evoked potential response to flashed light (F-VEP), indirect optic injury models were made in adult rabbits. The dynamic observation of orthograde axonal transport using HRP and the ultrastructure of injured optic nerve was carried out to realize the morphological changes.2 ABC immunocytochemical method was used to identify the axon growth of the injured optic nerve which was indicated by expression of the growth-associated protein GAP-43 and astrocytes by the appearance of glia fibrillary acidic protein immunoreactive cells.RESULTS 1 The amplitude of P1 decreased 47.38% in injured eyes comparing with that in control eyes and tend to be lowest at 1-2 weeks after injury, while P1 latency was delayed. Recovery of F-VEP in the injured eyes began from the 4th week after injury. Amplitude of P1 was more larger at the 8th week than that at 1-2nd week and tend to be normal at the 12th week, P1 latency shortened.