Background
Efforts to transplant a mammalian eye have failed mainly due to the ganglion cell axon’s inability to withstand transection. Eye transplantation is not feasible without proof of optic nerve regeneration. The objective of this pilot study is to find an optimal rat optic nerve transection and repair model in preparation for eye transplantation.
Methods
30 cadaver and 10 live Lewis rats were used to expose, transect, and repair the optic nerve and visualize its anatomical relationship with the ophthalmic artery. Nerve coaptation was performed with 12/0 suture. The pathway of the ophthalmic artery was evaluated by red latex injection.
Results
A combined superior orbital rim and lateral canthotomy (CSOR-LC) with partial temporalis muscle excision approach provided ideal access and sufficient operative space. The extra-ocular muscles were mobilized and the Harderian and lacrimal glands were retracted without gland excision. The ophthalmic artery branches approximately (101–38) mm proximal to the fundus. The retinal artery crosses the optic nerve postero-nasal pathway and divides the smaller branches (081–112) mm proximal to the globe. A supero temporal approach with minimal superior transection of dura mater providing scissor-tip access for nerve transection allowed maintaining the integrity of the ophthalmic artery and retinal perfusion.
Figure 1.
Conclusions
This model allows the repair of the optic nerve, preserving the integrity of the ophthalmic artery and retinal perfusion, therefore is ideal for studies evaluating optic nerve regeneration.