Transconjunctival Approach for Injection into the Rat Optic Nerve

The rat serves as an important model for studying disorders of the optic nerve, including heritable, traumatic, neoplastic, and autoimmune conditions. Accessing the rat optic nerve for experimental manipulations and injections is challenging due to the small size of the orbit and the vascularity of the surrounding orbital tissues. Previous techniques have involved a cutaneous incision, which carries a higher risk of infection and requires wound closure. This study aims to describe a unique, less invasive, and potentially more efficient approach to accessing the rat optic nerve. A transconjunctival incision, along with a rat spinal cord hook, is used to isolate the optic nerve for experimental injections. In these experiments, an adenoviral vector is injected into the optic nerve with the goal of using this technique for direct gene therapy delivery in the future. This technique can also be applied by investigators requiring access to the rat optic nerve for other experimental studies, including drug delivery and optic nerve injury research.