Medical Minute 7-11: Optic Nerve Damage

By: Vanessa Welch Email
By: Vanessa Welch Email

Ken Denison sells boats -- sometimes 100-million dollar boats. With a state-of-the-art command center, faux diamond and onyx baths, and a lot of expensive toys, even on a boat this big, having an eye for the littlest details can make or break a sale.

But one rainy summer morning, a wrong step, and a 10-foot fall to the ground suddenly turned out the lights.

"Immediately, the vision went out of this eye. It went black," Ken Denison.

Optic nerve injuries are the focus of Doctor David Tse's research at the University of Miami's Bascom Palmer Eye Institute. He says a forceful blow to the head can cause severe damage.

"The optic nerve gets injured, and the patient cannot see at all," said David T. Tse, M.D., F.A.C.S., Ophthalmic Plastic and Orbital Surgeon.

Ken's case? Very unusual. Three months after his accident, Doctor Tse, and some advanced imaging techniques, found something all Ken's other doctors had missed.13 pieces of wood chips, an inch long or more each, were embedded in Ken's eye socket, pressing on the optic nerve.

"You just wonder how you could've lived with that much stuff in the back of an orbit of an eye and not know something about it."

"He is one of the few, very very lucky patients."

Now, with 20-40 vision, Ken says the improvement is almost unbelievable.

"The week after that fall, I thought I'd never be where I am today."

A lucky man who will never stop appreciating big boats -- and little details.

For more information on other series produced by Ivanhoe Broadcast News contact John Cherry at (407) 691-1500, jcherry@ivanhoe.com.

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MEDICAL BREAKTHROUGHS - RESEARCH SUMMARY:

BACKGROUND: The optic nerve connects the eye to the brain. It carries the impulses formed by the retina, which is the nerve layer that lines the back of the eye and senses light and creates impulses. These impulses are dispatched through the optic nerve to the brain, which interprets them as images. Using an ophthalmoscope, the head of the optic nerve can be easily seen. It can be viewed as the only visible part of the brain. The optic nerve is the second cranial nerve. The cranial nerve emerges from or enters the skull, as opposed to the spinal nerves, which emerge from the vertebral column. There are 12 cranial nerves. The word "optic" comes from the Greek "optikos," pertaining to sight. (SOURCE: MedicineNet.com)

INJURIES TO OPTIC NERVE: Injuries to the optic nerve can result from a number of factors. These injuries can be caused by direct or indirect contact to the optic nerve. In all cases, treatment is essential because permanent vision loss can occur. When injuries occur, many complications with vision often result, including blurred vision, visual field defects, and difficulty seeing colors. When an injury occurs anywhere on the optic nerve, the transmission from the eye to the brain becomes interrupted. In some cases, damage to the optic nerve fibers can be permanent, which can result in permanent vision loss and blindness.
(SOURCE: healthguideinfo.com)

CAUSES: Any injury that occurs to the eye socket or head can lead to an injury of the optic nerve. Common causes of these injuries are motor vehicle accidents, falls and sports collisions. Assault can cause this type of injury as well. In some cases, the injury can result from a surgical complication, which can involve the brain, sinuses or eye socket. The optic nerve may be damaged as a result of a direct injury to the nerve, such as with a stab or bullet wound, or an indirect injury when an object hits the head and causes the nerve to swell and lose blood flow, such as a fall or punch.

TREATMENT: The treatment of traumatic optic nerve injury depends on the type of injury. If there is pressure on the nerve in the eye socket from blood or air, it may be necessary to have an emergency procedure called a lateral canthotomy to relieve the pressure. In this procedure, a small cut is made between the eyelids at the corner of the eye. The patient may also need eye drops to lower the eye pressure. If the bone is pressing on the nerve, the patient may need surgery to relieve the pressure on the nerve. This is called optic nerve decompression surgery. If there is bleeding around the nerve, the patient may also need surgery to try to relieve the pressure on the nerve from the blood. (SOURCE: summitmedicalgroup.com)

FOR MORE INFORMATION, PLEASE CONTACT:
Omar Montejo, Media Relations
University of Miami Miller School of Medicine
Miami, FL
(305) 243-5654
Omontejo@med.miami.edu

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THE FOLLOWING IS AN IN-DEPTH INTERVIEW WITH THE DOCTOR FROM THE STORY ABOVE.

David T. Tse, MD, FACS, an ophthalmic plastic and orbital surgeon from the Bascom Palmer Eye Inst. at the University of Miami Miller School of Medicine, talks about a surgery that gave one man his sight back.

Tell me about the optic nerve, what is so perplexing about optic nerve injuries?
David Tse: Well in my subspecialty I deal with trauma to the optic nerve. If you look at the optic nerve as a television cable the eye being the camera that connects to a cable that connects to the back of the brain to see. The camera can be perfectly normal but if the cable is traumatized as in a fall or in a punch to the eye or in a car accident the optic nerve gets injured and the patient cannot see at all, even though the eye is perfectly normal. And that’s an injury to the optic nerve and it’s unfortunate that it is irreversible blindness.

In a scenario where somebody falls the optic nerve is injured, that’s it. Tell me about that.
David Tse: Well the traditional method of treating falling, a car accident, being punched in the side of the head or any kind of accident and the treatment is traditional. It’s a high dose systemic steroid or go in to the socket and try to open up the canal in which the optic nerve goes through. The idea being is to open up and give this more space for the swelling of the optic nerve to go in to. So and we have multiple studies, prospective study to indicate that neither high doses systemic steroid nor optic canal decompression is helpful in saving vision. So essentially it’s a very disappointing condition in which there is no effective therapy at all.

So you were saying something simple could happen.
David Tse: Often times they have other comorbidities in an accident, car accident for example, and once they become more conscious and then you examine the eye and they cannot see out of one eye. Or they have a child with a fall from a bunk bed for example and they cannot see out of one eye, and the eye being totally normal and that’s because the optic nerve was injured during the fall. And so unfortunately it’s an irreversible blindness.

With your research, you’re trying to find a way but you probably have a particular interest when somebody comes through the door that has something wrong with their optic nerve?
David Tse: Yeah, this is one of the more devastating conditions that I manage in my subspecialty. Often times we can get to the patient early enough perhaps we can intervene but by in large most of these patients come in late and then the window of opportunity of saving the eye is over and then they end up with a blind eye. So we like to intervene as early as we can and often times there may be a reason why they can’t see. For example, blood around the optic nerve which you can evacuate, blood inside the nerve that we can evacuate. But by in large you don’t often times see a fracture around the canal or you don’t see anything that you can do surgically and yet they cannot see. And that’s what’s frustrating about traumatic optic neuropathy and currently there is no way, no method, no treatment for this condition, either medically or surgically.

But then there are patients like Ken who come in to you, what was going on with him?
David Tse: Well Ken was a little bit unusual, is that he sustained injury several months before coming down to see us from his fall. And in him he has some unrecognized foreign bodies trapped inside the orbit touching and then pinching on the optic nerve. And we were able to see it and recognize it and go back and remove those foreign bodies and fortunately his vision returned.

Were they’re things you could see right away or did you have to have a special instrument?
David Tse: Well it was an index of suspicion that we had given the history of the unusual fall and that he had some cuts around the forehead and around the eye. And the key piece of information that he gave us was a few months after the injury a piece of wood began to extrude from his forehead. And the fact that his eye cannot move and then he was having some blood oozing out under the eyelid gave us the impression that he probably had entrapped foreign body in the socket that was not recognized. And the blood was coming out from a fistula, a communication between the inside the orbit and the outside. So through that track we were able to trace and find the multiple wood chips embedded and impacted in the socket.

What did you do, how did you realize they were there?
David Tse: Well we saw an opening under his eyelid that unless you flip his eyelid over you can’t see the clue, and he had an opening under the eyelid. So unless you flip his eyelid you can’t find the entrance point, the entry point for that. So the history that he was having bloody tears on the pillow in the morning gave us a clue that there is a communication and fortunately we were able to find the opening.

So you looked in there and what did you see and how big were they?
David Tse: Well the opening was quite small but you can see the bloody tinged fluid coming out, so that’s a clue. And then we imaged him and we were able to find some unusual findings, something very, very straight in the socket. Normally you don’t find a structure in the eye that is that straight and so that immediately gave us the impression that he had some foreign body in there so we went in and explored and fortunately we were able to evacuate all the wood particles that got impaled inside the socket.

How many pieces did you pull out and how big was the biggest one?
David Tse: About thirteen pieces and each one was about three centimeters long.

How big is three centimeters?
David Tse: About this long.

Those were in his eye?
David Tse: In the socket behind his eye.

So knowing that why couldn’t he see?
David Tse: Because the wood chips were pressing on the optic nerve. And so that’s why the optic nerve was not working, so once we removed it his optic nerve was able to recover and function.

So this is one of the cases where you actually can do something about it.
David Tse: He is one of the few very, very lucky patients. That we were able to identify the cause and then address the problem, and fortunately he has enough reserve in his optic nerve to recover some function.

How rare is that?
David Tse: Extremely rare and so many months after the injury.
T
he optic nerve is pretty unforgiving?
David Tse: The optic nerve is just like any kind of neural structure in the body, just like the spinal cord. It’s very unforgiving, yes.

And once you’ve hurt it most of the time that’s it?
David Tse: Once you traumatize it it’s really you get an irreversible damage. He’s very, very fortunate that we were able to save his vision.

When he came to you what could he see out of that eye?
David Tse: He could barely see his hand moving in front of him.

And now?
David Tse: He’s 20/40.

Did you do it right in your office?
David Tse: No, so here’s another thing. One of the reasons the previous admitting doctor didn’t see it was to image wood is extremely difficult unlike imaging a piece of metal, you can see it. A piece of wood is very, very hard to image so once we had the indexes suspicion we kind of focused in and requested a special test. We also used ultrasound to identify the foreign body. But more importantly to go in and to explore and find and remove the foreign bodies in him. And certainly it had a lot of scarring surrounding the wood being that they had been there for so long. But it was a challenge in removing it. In the process of evaluating for surgery under general anesthesia we noticed that he had a heart conduction defect that required some treatment beforehand. So he had a heart problem that he didn’t even know about and so we were able to treat that, stabilize it before we put him to sleep.

A heart problem?
David Tse: Yeah he had a heart conduction defect.

So you didn’t treat that?
David Tse: No we identified it in the processing of working him up and getting him ready for surgery on the EKG we noticed that he had an electrical conduction defect.


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