Which nerve is primarily involved in reflex uveitis associated with corneal ulcers?

Reflex uveitis occurs when a corneal injury leads to inflammation of the uveal tract, which includes the iris, ciliary body, and choroid. The trigeminal nerve plays a crucial role in this process because it is responsible for sensory innervation to the cornea. When the cornea is damaged or ulcerated, sensory receptors in the corneal tissue are activated, and this information is transmitted to the brain via the trigeminal nerve.

Once the brain receives this sensory information, it can trigger a reflex response that results in inflammation of the uveal tract as a protective mechanism. This reflexive connection is how corneal ulcers can lead to uveitis, as the trigeminal nerve mediates the response due to its association with the cornea. The other nerves mentioned do not have the same direct involvement in reflexive responses originating from corneal sensitivity. The optic nerve primarily transmits visual information, the facial nerve is primarily associated with facial muscle movement and sensation, and the oculomotor nerve controls most eye movements and pupil constriction but does not have the same sensory role as the trigeminal nerve when it comes to corneal reflexes.