Neurotrophic keratopathy is caused by

*This occurs in some cases in which the trigeminal nerve is paralyzed, typically as a result of radical treatment for trigeminal neuralgia. *The characteristic feature of neurotrophic keratopathy is the desquamation of the corneal epithelium. The surface of the cornea becomes dull and the epithelium is thrown off. *The entire epithelium may thus peel off intact. The substantia propria then becomes cloudy and finally yellow, breaking down into a large ulcer which is usually accompanied by a hypopyon. *There is no pain, owing to the anesthesia, but ciliary Injection is marked. Neurotrophic keratopathy is a degenerative corneal disease induced by an impairment of trigeminal nerve. Impairment of loss of corneal sensory innervation is responsible for corneal epithelial defects, ulcer, and perforation. Ref Parsons' 21st edition; Pg.115