<prompt> Neurotrophic keratitis involves which nerve: September 2008TrochlearTrigeminalAbducensFacial  <response>: Ans. B: Trigeminal Neurotrophic keratopathy occurs in cases in which trigeminal nerve is paralyzed, typically as a result of radical treatment for trigeminal neuralgia. It does not occur in all cases of peripheral lesions of the trigeminal nerve; thus, if the gasserian ganaglion is removed or the trigeminal nerve with alcohol for trigeminal neuralgia with proper precautions, only a few cases develop neurotrophic keratitis. Neuroparalytic keratopathy is seen in facial nerve palsy as occurs in Bells palsy, leprosy or neurological disorders leading to ectropion, lagophthalmos and exposure keratopathy. 