Why is vision loss worse for veterans with traumatic brain injury?

At the 2009 American Academy of Ophthalmology (AAO) - Pan-American Association of Ophthalmology (PAAO) Joint Meeting in San Francisco, researchers presented a new VA study and reported that Iraq and Afghanistan veterans who suffered vision loss as a result of a traumatic brain injury have significantly poorer quality of life than civilian patients.

Traumatic brain injury can occur as the result of an explosion, car bomb, blast injury or direct hit of the brain from warfare or fragments. During these explosions, the eyes are particularly vulnerable to injuries that lead to structural damage within the eye. Over time, the structural damage can result in glaucoma, double vision, optic nerve injury, changes in the vision field, and other serious vision problems.

The study  determined that about 20 percent of those with neuro-ophthalmic vision loss also suffer with recurrent hallucinations. Many veterans do not mention the hallucinations for fear they are linked to mental illness. The visually impaired veterans with traumatic brain injury may “think” they see wild animals in their closet or people sitting on a couch facing them. This problem, called Charles Bonnet Syndrome (CBS), is common in people with age-related macular degeneration.

Once veterans with vision loss from traumatic brain injury begin to understand the hallucinations, they can start to distinguish the imaginary shapes and learn to ignore them. Sometimes medication is prescribed to help visually impaired veterans deal with the hallucinations.