Chat Highlights
Cutting Surgery for Glaucoma
February 16th, 2000

Norma Devine, Editor

On Wednesday, February 16, 2000, Dr. Rick Wilson, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Cutting Surgery for Glaucoma."

Dr. Wilson: The topic tonight is Cutting Surgery. Any questions?

P: Does glaucoma always lead to surgery?

P: Good question.

Dr. Wilson: No, most folks are controlled without surgery.

P: Rick, are younger patients more likely to need surgery?

Dr. Wilson: Yes, because they have glaucoma over a longer period of time.

P: Lucky us!

P: Dr., do people who have a trabeculectomy all feel like they have something in their eye?

P: I don't feel like I have something in my eye.

Dr. Wilson: No. That is usually because the eyes are dry, and with the bleb sticking up and causing more friction, the result is irritation.

P: Rick, how long does a trab usually last and does the person's age matter?

Dr. Wilson: It has been said to last seven years on average, but that was before antifibrotic agents that have increased the life of the blebs. Younger people heal better and blebs tend to last for a shorter period.

P: How do you decide whether to perform a bleb needling or a revised trab (trabeculectomy)?

Dr. Wilson: If there is a small bleb that I can get to under the conjunctiva with a needle blade, then I would needle. Otherwise, I would repeat the trabeculectomy.

P: Rick, what does it mean that my eye "has no structure"?

Dr. Wilson: The eye wall may be flimsy and if the vitreous jelly on the inside is minimal or has been removed, then the eye might collapse.

P: Rick, if Mitomycin-C is used, does that help the filter last longer?

Dr. Wilson: Yes.

P: Dr., I am 38, have tried four (kinds of drops), two lasers in each eye, my psd's look worse each year on my vf (visual field tests), my doc is talking trab (trabeculectomy) and I'm really scared. Any words to make me reconsider it?

Dr. Wilson: Well, if you are definitely getting worse, the only chance you have is to take a small risk of losing a lot of vision with surgery, but if you get through that period, having a much greater chance of saving your vision for life versus having a 100% chance of continuing to lose your vision at a relatively young age.

P: What are psds?

P: Pattern standard deviation.

P: Rick, what if your bleb is starting to scar? Do you just watch it scar over?

Dr. Wilson: I usually try digital ocular compression (massage).

P: Dr., I am 42 and was recently diagnosed with low pressure glaucoma and I have some optic nerve damage. I had an MRI and it was negative. What are the causes for glaucoma if it isn't the eye pressure?

P: What's an MRI?

P: MRI stands for magnetic resonance imaging.

P: I think they use MRI to see if a tumor is the cause.

Dr. Wilson: Causes for normal tension glaucoma include an undetected pressure spike during the day, low systemic blood pressure, autoimmune disease (rare), and vasospastic disease like migraines.

P: Doc: What surgeries are applicable to angle closure after iridotomies fail?

Dr. Wilson: A gonioplasty with a laser, a goniosynechiolysis surgically and a trabeculectomy are your choices. A laser will only work in the acute stage. A goniosynechiolysis will work up to 6 to 12 months after the original angle closure, and a trab would work at any time.

P: Rick, do nanothalmic (dwarf-like) eyes make a difference?

Dr. Wilson: It's more difficult is all.

P: Rick, if someone wanted to know how to check to see if her opthamologist is a glaucoma specialist, is there a way to do that?

Dr. Wilson: The American Glaucoma Society is about to release its website. There you will find the more established glaucoma specialists. I'll let you know what the address is after our meeting in early March.

P: Is the patient awake during surgery?

Dr. Wilson: If the patients are young, they can be sedated as heavily as they want.

P: After anesthesia wears off, how much pain is there?

Dr. Wilson: There should be no problem.

P: Rick, why, after the anesthetic injection, can we not see with the eye to be operated on?

Dr. Wilson: The anesthesia numbs the vision nerve as well as the pain nerve. The anesthesia I use lasts for close to 24 hours.

P: Dr. Rick, my doctor wanted to put 100% alcohol in my eye to kill the pain; what can you tell me about this?

Dr. Wilson: If your eye is sightless and painful, this works to kill the pain. If the cornea has broken down with swelling, however, it is an invitation to a corneal infection because you will not be able to feel problems developing in the cornea until it is too late.

P: Doctor, one question, nothing to do with surgery. If one sees rainbow halos around lights and has pain in the eye, does it mean that glaucoma has worsened?

Dr. Wilson: Most of the time rainbows around lights come from corneal swelling that can accompany high eye pressure. Other causes cannot be excluded.

P: What other causes, Dr., would the opthalmologist be able to say if I have corneal swelling, or does it happen only when the pressure becomes high?

Dr. Wilson: Anything that causes swelling of the cornea, such as trauma, inflammation, infection, etc.

P: Dr. Wilson, I am seeing a cardiologist on Friday. Is there anything I should ask/tell him regarding having normal-tension glaucoma?

Dr. Wilson: He should investigate anything that would decrease your "perfusion to the optic nerve". Remember that phrase. This could include a faulty heart rhythm, low blood pressure, and a build-up of cholesterol in the vessels that supply blood to the eye.

P: Doc, does low blood pressure only matter in NTG?

Dr. Wilson: No, it can matter in any kind of glaucoma. One of the worst prognostic factors is low perfusion pressure, i.e. the diastolic blood pressure (the lower one) minus the eye pressure is low.

End of highlights for February 16th chat.

If you would like to read more about cutting surgery, click here.

On February 23th, Dr. Wilson discussed Unconventional Glaucoma Treatments in the Chat room. Click here for highlights of that meeting.

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