<prompt> Nerve involved in exposure keratopathy: September 2009Third cranial nerveFifth cranial nerveSeventh cranial nerveNinth cranial nerve  <response>: Ans. C: Seventh cranial nerve Exposure keratitis may occur in any condition in which the ocular surface is not properly lubricated and covered by the eyelids. The most common conditions associated with the development of exposure keratitis include Bells palsy, exophthalmos associated with Graves disease, and ectropion. If the eye is not properly covered by the eyelids or blinking is ineffective or absent as in Bells palsy, the cornea may dry out resulting in exposure keratitis. This condition is characterized by pain or discomfo, blurred vision, and even permanent loss of vision in some cases due to corneal ulceration or the more dreaded perforation of the cornea. Exposure keratitis is treated based on the underlying condition. Prevention of the condition is the best management. In the cases of Bells palsy and ectropion, a minor plastics procedure may decrease or eliminate the exposure of the eye. If exophthalmos associated with Graves disease is the underlying cause, an orbital decompression procedure may be appropriate. Immediate management of patients with exposure keratitis is based on lubrication with aificial tears or ointments and reduction of the exposure, either with shields or patching of the affected eye 