The optic nerve

Results of an international study have demonstrated a shared immune surveillance mechanism between the brain and the eyes.

Researchers, led by Dr Eric Song from the Department of Ophthalmology and Visual Science at Yale School of Medicine, vaccinated mice intravitreally with inactivated herpes virus and discovered lymphatic vessels in the optic nerve sheath protected the mice not only from herpes infections, but from bacteria and even brain tumours. This reveals a shared lymphatic circuit able to mount a unified immune response between the posterior eye and the brain, they wrote in Nature. “This highlights an understudied immunological feature of the eyes and opens up the potential for new therapeutic strategies in ocular and central nervous system diseases.”

The team is now developing new intravitreal drugs to treat macular oedema to exploit this connection, said Dr Song.