Welcome to the TBI-HELP Live Chat

Today's topic is: "Eye Rehabilitation for Traumatic Brain Injury"

Our Guest is: Dr. Lawrence Blum,  
Optometrist, Jamaica Hospital Medical Center

[18:59:37] Mod: Good evening and welcome to our chat session. This evening we are please to have with us Dr. Lawrence Blum, Ophthalmologist from Jamaica Hospital Medical Center. Welcome Dr. Blum..
[19:00:47] drblum: Thank you for having me..
[19:01:12] Mod: Dr. Blum, what types of eye problems do you see after a traumatic brain injury?
[19:04:22] drblum: There are many types of eye problems after a traumatic brain injury. The injury can be to the visual cortex, or directly to the optic nerve There can also be injuries to the nerves that control the eye movements or the control of the eyelids..
[19:06:50] Mod: Rail: How much eye and vision problems are linked to brain injury rather than eye or optic nerve damage?
[19:07:49] drblum: For this discussion I am specifically leaving out direct injury to the eye.
[19:09:03] Mod: What other types of eye problems may a TBI bring about?
[19:09:56] drblum: I will be concentrating specifically on injury to the visual cortex which can cause problems with visual field defects or problems with processing visual information correctly..
[19:10:08] Mod: What would cause the loss of central vision?..
[19:11:29] drblum: Loss of central vision is most likely related to optic nerve injury. When the nerve is damaged we refer to this as a Traumatic Optic Neuropathy..
[19:13:25] Mod: Benny: What are some of the ways you can diagnosis eye problems in a TBI patient?
[19:14:40] drblum: When the patient is in the acute phase of the injury and cannot respond we rely on the pupillary response as well as reaction to bright light..
[19:16:00] Mod: Benny: How can one ascertain if vision is getting better or worse in TBI patients that cannot communicate?
[19:16:25] drblum: A patient can have completely normal central vision and impaired peripheral vision The most common cause of this in my experience are damage to one side of the visual cortex. this causes peripheral field defect on the opposite side of the injury..
[19:19:10] Mod: Albert: What has the success rate been in reversing nerve damage?..
[19:21:17] drblum: Albert, The success rate for reversing nerve damage is very variable and there are no good data. The best results are when the diagnosis is made immediately and the patient is started on a regimen of high dose steroids
[19:22:37] Mod: Albert: Is there any way to correct the damage by surgical interventions?..
[19:23:55] drblum: The optic nerve can be decompressed in some very specific situations, usually when the ct scan shows a hematoma around the nerve or a bone chip protruding into the optic nerve..
[19:25:45] Mod: Carol: What are some of the exercises that can be done to increase vision or enhance the vision?..
[19:26:21] drblum: The response of the eye to "exercise" is a highly controversial issue. The eye does not really respond like a muscle to increased use. If there is a paretic muscle that controls eye movement in a specific direction exercise does not seem to help. Vision loss due to a nerve injury does not respond to overusing the eye. Luckily the central nervous system as well as the peripheral nervous system has the ability to repair itself to some extent..
[19:32:22] Mod: Carol: Do you have any information on what the latest technologies are especially computers or the use of microchips implants in improving vision?
[19:34:13] drblum: Carol, They are in the earliest stages of implanting computer chips into the retina to try and transmit signals to the brain. This has been done successfully. We are still a long way off from being able to convert the signal into a discernible image..
[19:36:35] Mod: Alice: Does the eye have the ability to repair itself to some extent
[19:37:56] drblum: Alice, the visual cortex as well as the optic nerves to have the abilty to regain function. Damage to the nerve or cortex can take from 6months to one full year to regain some function. It is common for me to see a patient with a dense visual field defect recover significantly over a few months..
[19:40:43] Mod: What are the causes of double vision?
[19:41:56] Mod: Welcome Mike and Amanda!
 nerves at the time of the injury. There are 6 muscles attached o the eye that pull or rotate it. Complete or partial damage to any of these muscles will cause a misalignment..
[19:45:12] Mod: Amanda: Is not being able to track an eye problem or a cognitive problem?
[19:47:06] drblum: Amanda, The ability to track is both cognitive as well as a function of the oculomotor system. It is very common after a traumatic injury to the brain to see problems with tracking objects. It is a very diffuse system controlled at higher cortical levels as well as brainstem levels. The cerebellum is also involved..
[19:50:43] Mod: Sometimes the pupils are affected in that they will not respond to light but one can still see, how can we get the pupil to respond?
[19:52:26] drblum: The control of pupil size and response to light is independent system. You can have unreactive pupils and normal vision. Some brain injuries cause small pupils and some cause dilated pupils. If the patient is able to respond than this situation is not a problem. If the patient is unable to communicate or in a coma and the pupils are not reactive we lose the ability to make an early assessment of optic nerve function..
[19:56:34] Mod: Joeboo: Are there some visual functions that can appear to be impaired but are really a result of some other component of the TBI?..
[19:58:46] drblum: Joeboo, Yes, this is a common situation. It is common for some TBI patients to have damage to there speech and comprehension centers. In right handed people this is usually of the left side of the brain. Damage to this center can cause the patient to lose the ability to name common objects correctly. When reading the eye chart they will misname letters of any size. In some cases they cannot name the object but can write down the correct name on paper. This is called an aphasia..
[20:01:53] Mod: I see that our time is up and I want to take this opportunity to thank Dr. Blum and to invite him back in the future. Good night to all and be safe!
[20:02:33] drblum: thank you