Final answer:
The condition that indicates the need to maintain eye closure in a patient with a traumatic brain injury is loss of the corneal reflex.
Step-by-step explanation:
The condition that indicates the need to maintain closure of the eyes in a patient with a traumatic brain injury is loss of the corneal reflex. The corneal reflex is a protective response that causes blinking of the eye when the cornea is stimulated. In this case, the loss of the corneal reflex suggests damage to the nerves responsible for triggering the blink response, which necessitates the maintenance of eye closure to protect the injured eye.