Neuro-ophthalmology
Chat Highlights
May 5, 2010

On Wednesday, May 5, 2010, Dr. Mark Moster and the glaucoma chat group discussed "Neuro-ophthalmology".

Moderator: Good evening everyone. I would like to welcome Dr. Mark Moster back to the chat room. In addition to being Chairman of Neuro-Ophthalmology at Albert Einstein Medical Center, Dr. Moster is also a professor of Neurology at Jefferson Medical College and on the Neuro-Ophthalmology Service at Wills Eye Institute in Philadelphia, PA. Dr. Moster, can you first tell us, what is a neuro-ophthalmologist?

Dr. Mark Moster: We deal with eye symptoms that are from illnesses in the brain or nervous system.

Moderator: Is there any special training?

Dr. Mark Moster: The training is a residency in either ophthalmology or neurology, followed by a fellowship in neuro-ophthalmology. In my case, I trained in neurology.

P: When and why would a glaucoma patient be referred to a neuro-ophthalmologist?

Dr. Mark Moster: The most common reason for referral is when there is a question about whether the eye symptoms and signs might be due to something other than glaucoma.

P: If I am referred to a neuro-ophthalmologist, does it matter what residency the doctor went through, neurology versus ophthalmology?

Dr. Mark Moster: The fellowship training is very similar and it likely doesn't matter, except there are some people who are very sub-specialized, such as only dealing with eye movements.

P: What form of glaucoma is usually referred to your practice?

Dr. Mark Moster: Most often it is NTG. Since the pressure is normal, it raises the possibility that something else is going on. Also, when a patient with glaucoma of any type seems to be worsening unexpectedly, it raises the possibility of something else and then we should see them.

P: Does an ophthalmologist easily determine when there is a need to be referred to a neuro-ophthalmologist, or is it easily missed?

Dr. Mark Moster: Yes, most ophthalmologists easily know that.

P: Is the determination by the patient’s physician made based on visual fields?

Dr. Mark Moster: That is one of the possibilities. The diagnosis of glaucoma is usually made on visual fields, optic nerve appearance, and pressure. However, other conditions can cause similar abnormalities. It may be fields or the nerve appearance that causes the referral. The most important condition that can mimic glaucoma is a benign tumor pressing on the visual pathway. Other conditions include vitamin deficiencies, inflammation in the nerve, and stroke in the nerve. Sometimes degenerative conditions can mimic glaucoma.

P: What would be atypical in a normal tension glaucoma patient to warrant an evaluation by a neuro-ophthalmologist?

Dr. Mark Moster: First, there would be a visual field that is different from what is expected. Secondly, there would be an optic nerve that looks a little too pale in color. Thirdly, there would be a visual acuity that is poorer than expected. Finally, there would be finally, a more rapid progression of glaucoma damage than previously, despite good intraocular pressure (IOP).

P: What differentiates the visual fields of other neurological diseases from the visual fields of glaucoma patients?

Dr. Mark Moster: Most glaucoma defects begin in the nasal half of the field. Neurological fields are often more in the temporal half, the center, or have a border on a line in the center of vision.

P: Is the temporal half by my nose or towards my ears or towards the top of my head?

Dr. Mark Moster: The temporal half is toward your ears and nasally is toward the nose.

P: How does an optic nerve that has been affected by some illness differ from the appearance of an optic nerve damaged by glaucoma?

Dr. Mark Moster: In glaucoma, the cup in the center enlarges gradually. The cup is pale in color, more white than yellow or pink. The outside rim remains normal color. In neurological disease, the rim becomes pale or white as well.
The visual fields can also be different. For instance, patients with a pituitary tumor will lose the vision in the right eye towards the right ear and the left eye towards the left ear.

P: Is there a symptom a patient might have that always needs further evaluation from a neuro-ophthalmologist?

Dr. Mark Moster: I think if there are other neurological symptoms such as severe pain, double vision, numbness, drooping eyelid, or bulging of the eyes, then a referral is in order.

P: Can migraines worsen optic nerve damage in a glaucoma patient?

Dr. Mark Moster: We know that migraines and glaucoma are associated with each other. I don't think we know for sure if migraines worsen the damage.

P: Could there be neurological cause if the visual field defect is monocular?

Dr. Mark Moster: Absolutely. A tumor can be pressing on one optic nerve behind the eye. Inflammation and stroke can occur to only one eye.

P: Is the type of vision loss in patients you see reversible?

Dr. Mark Moster: Sometimes it is, if you take out a tumor in time, or if you treat an inflammation or infection.

P: What does a complete workup by neuro-ophthalmologist consist of? Do I get a visual field and do I get my pressure checked or does it depend on why I am there?

Dr. Mark Moster: It does depend on why you are there. However, if it is to look for another cause mimicking glaucoma, it will include a full eye exam, examination of the orbit and eye movements, visual field, dilated retinal exam and possibly imaging which is similar to a glaucoma evaluation.

When we think there may be something else going on, most often patients will be sent for an MRI of the brain and orbits. There will also likely be blood work done as well.

P: When would one need an MRI of orbits and would it be with gadolinium (contrast)?

Dr. Mark Moster: If you suspect the problem is directly behind the eye and not further back in the brain. We also use contrast whenever we can, otherwise we can miss inflammation or tumor.

P: Do tumors in nasal areas possibly cause glaucoma symptoms as well?

Dr. Mark Moster: Not so much nasal (as in nose) tumors but sinus tumors can.

P: Do you encounter patients with chronic eye pain? I have chronic pain post vitrectomy, and it feels like vice grip sometimes. The doctors say it could be nerve pain. Is there help for nerve pain?

Dr. Mark Moster: The nerves that supply the eye are the most sensitive in the body. For instance, if you touch anywhere else on the body softly, it would not hurt nearly as much as touching the eye. There are various medications that can dampen and sometimes eliminate nerve pains.

P: Is there any connection between patients with myotonic dystrophy and glaucoma problems or angle closure issues?

Dr. Mark Moster: I have not heard of that connection; however, glaucoma is so common that people with myotonic dystrophy can certainly have it.

P: Is there a connection between patients with multiple sclerosis (MS) and glaucoma? If so, what is that connection?

Dr. Mark Moster: We certainly can see patients who have optic nerves that look like glaucoma from MS; however, there are usually features that distinguish the two illnesses.

P: I would like to ask about the nerve issues relating to glaucoma. Is aching in the back of the eye normal in advanced glaucoma?

Dr. Mark Moster: No. The only painful glaucoma would be angle closure.

P: What would be its cause then? It feels like muscle strain.

Dr. Mark Moster: Well, a lot of things can cause pain behind the eye such as sinus infections, tension headache, migraine, various neuralgias, medication overuse, etc. Sometimes no cause is found.

P: Dr. Moster, how is it determined whether a stroke has caused symptoms mimicking glaucoma?

Dr. Mark Moster: If it is a stroke behind the optic chiasm (where the information crosses in the brain) then the field loss will be on the same side of space in both eyes, so nasal in one and temporal in the other. If the stroke is to the optic nerve, then the optic nerve will turn pale and the visual acuity will most often be worse than in glaucoma.

P: Does pain directly behind the eye feel different than pain in the brain?

Dr. Mark Moster: It is often hard to tell. Many causes of pain anywhere in the head can be referred behind the eye.

P: Isn't there pain sometimes that you feel in one place but its cause actually originates elsewhere?

Dr. Mark Moster: Yes, that is called referred pain. It is like the pain you can get in the left arm with a heart attack.

Moderator: Dr. Moster, there are no more questions in the queue. Thank you so much for your time and great answers.

Dr. Mark Moster: Okay, thank you. Good night everyone.

On May 19, Dr. Pro discussed "Optic Nerve Imaging" in the Chat room. Click here for highlights of that meeting.

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