New Surgical Treatments: Express Shunt, Canaloplasty and Trabectome

New Surgical Treatments: Express Shunt, Canaloplasty and Trabectome
Chat from September 17, 2008
Guest Speaker – Dr. George Spaeth
Steven Beck, Editor
Lorraine Miller, Editor, Chat Topic Researcher

On Wednesday, September 17, 2008, Dr. George Spaeth, a glaucoma specialist at Wills, and the glaucoma chat group discussed “New Surgical Treatments: Express Shunt, Canaloplasty and Trabectome”.

Moderator: Tonight our topic is New Glaucoma Surgeries—Express Shunt, Canaloplasty and Trabectome.

Dr. George Spaeth: The basic premise is that glaucoma surgery helps by lowering and or stabilizing the eye pressure (IOP). Shall I give my opinions about these new procedures?

Moderator: Sure. We’d love to hear them.

Dr. George Spaeth: OK. The Express Shunt is a modification of a filtering procedure; no big deal. It’s perhaps an advantage, perhaps not. But in some people’s hands it works as well or better as any of the filtering procedure that make a hole to let the aqueous drain.

Canaloplasty and deep sclerectomy are considered by some to be procedures that shunt the aqueous out the canal, not through the sclera. I personally don’t believe that. They have the potential advantage of not making a bleb, but they also don’t seem to work well.

Trabectome and others like it ream out the meshwork, the idea being that the fluid can run out more easily. It usually can at the start, but these operations have not lasted well.

P: Do you perform any of these procedures?

Dr. George Spaeth: I have done them all in various modifications, but because I did not do them well or they did not work for me, I concentrate on doing the best trabeculectomy, or tube, or goniotomy, or trabeculotomy that I can.

P: When you say they haven’t lasted well, it that because they are failing sooner, or they haven’t been around long enough to get good long-term results?

Dr. George Spaeth: They fail sooner. When you get a good filtering bleb it usually lasts the rest of the person’s life. That is not true for any of the other operations.

P: When you say theses new procedures fail sooner, can you define sooner?? Three days, three months, three years?

Dr. George Spaeth: With trabectome, it is maybe one year. It is really important to remember that everybody has different genes and different propensity to scar and to have complications.

P: Does each procedure stimulate cataracts they way a trab does?

Dr. George Spaeth: I think that cataract as a result of trab is the result of the way the trab is done. If the chamber is flat or one uses steroids for more than four weeks the likelihood of a cataract increases. If the chamber remains formed and steroids are limited I DO NOT THINK THAT TRABECULECTOMRY CAUSES CATARACT [sic].

In an NIH study on trabs we had seven percent cataract after five years and another major center had 59 percent cataract after 5 years!

P: That’s quite a difference in results, Dr. Spaeth.

Dr. George Spaeth: You bet.

P: Which of the three procedures has the best chance to become the premier procedure?

Dr. George Spaeth: I don’t think there is a premier procedure. There are different strokes for different folks.

P: My trab lasted for 17 years, but the bleb went flat. What are the chances of it lasting longer? I developed scar tissue.

Dr. George Spaeth: If you have pigmented skin, trabs are more likely to fail. If you don’t once they work they often work “forever.” However, even in people with no pigment the trab can scar down, although that is not usual.

P: So a good trabeculectomy doesn’t last for seven to 10 years? What would you define as a good filtering surgery?

Dr. George Spaeth: A trab that results in a bleb that is diffuse should last a lot longer than seven to 10 years.

P: Dr. Spaeth, you don’t sound nearly as optimistic about the new surgeries as some other doctors.

Dr. George Spaeth: No, I’m not. In fact, I am very dubious that they will offer a better future. In contrast, there are modifications in the way trabs are done that make it a beautiful operation. Remember, there are many reasons why surgeons do new things, and only one of them is because the new thing may be better.

P: May we ask what are some of those other reasons that doctors will go for new methods even if they are not better??

Dr. George Spaeth: Because they attracts patients, who, for reasons that I can not understand, always seem to want the newest thing. The newest thing is almost NEVER the best thing. Osler – a great physician said, don’t be the first to try something and don’t be the last to give something up. Good advice!

P: What is a “bleb that is diffuse”?

Dr. George Spaeth: A diffuse bleb is one that spreads out over a wide surface. When mitomycin is applied in one area only the blebs are rarely diffuse.

P: That’s very interesting Dr. Spaeth. Are the improved methods for performing trabs being taught outside of Wills?

Dr. George Spaeth: They started at Moorfields Eye Hospital in London , with a brilliant, compassionate surgeon named Peng Khaw. He showed that when mitomycin is placed over about 180 degrees, the blebs become diffuse. The new methods take longer, and require the use of releasable sutures, which give more control.

P: Are the doctors in the UK still going for surgery first instead of drops first?

Dr. George Spaeth: No, they never really did. What they were saying is that in SOME patients surgery is best first and in SOME patient surgery should be done only as a last resort.

P: How do they determine the difference, i.e. who is best for surgery first versus who is best for surgery last?

Dr. George Spaeth: Some patients don’t take their medications or have severe glaucoma or have a great likelihood to have a successful result. Some patients really know how to care for themselves, or have many risk factors for surgical failure. The first group do better with surgery, the second with medication.

The whole matter of new surgical procedures is a fascinating matter. When Cushing first started removing pituitary tumors he killed his first 18 patients, but now the procedure saves lives all the time. The first intraocular lenses cause eyes to become blind; now they restore vision miraculously.

The real question is is the surgeon honest with the patient. I hope I have tried new things, but only when the patient knew I was trying something new and that it might not work, or might make him/her worse.

P: Can you have trabectome done after you already have had a trab in that eye?

Dr. George Spaeth: Yes

P: Are there types of glaucoma where the newer surgeries may be more appropriate? Or certain patients for whom they are more appropriate?

Dr. George Spaeth: I think that glaucoma in young folks may be a good group for trabectome or trabeculotomy. Trabeculotomy is an old, old operation, rather like a trabectome, that has been used by many surgeons. It has not become popular because it does not last well and is difficult to do. Express shunts may be good for myopes or non-pigmented patients with no inflammation.

P: What do you consider young, when you say the newer surgeries might be good for young people.?

Dr. George Spaeth: Less than age 20 years.

P: Why might express shunts be good for myopes?

Dr. George Spaeth: Because the sclera is thin and it is hard to make a good flap.

P: Dr. Spaeth, my 21 year old daughter has aphakic glaucoma. She had a trab then a shunt in her left eye and ended up losing the eye due to retinal detachment surgery/complications. She has good vision in her right eye but the pressure is a concern. The optic disc is in pretty good shape. My question is this: If the need should arise for a surgery in the right eye, might a canaloplasty be an option for someone like her? We are very concerned that a serious complication might develop with the trab or shunt and this is her only remaining eye. Is it true that canaloplasty may have fewer devastating complications?

Dr. George Spaeth: Yes it may. However, I would advise do not do surgery until it is certain that she will lose vision if no surgery is done. Next, when the surgery is done, do the surgery that the surgeon is best at doing. That may be a tube or a trab or an express shunt or a deep sclerectomy or a canaloplasty.

P: Doctor, how do I know if my surgeon is good?

Dr. George Spaeth: Another great question! What do other doctors say about him/her. Is the doctor honest with you? Does the doctor tell you how many of those procedures he/she has done?

P: You mentioned earlier, a good filtering bleb usually lasts the rest of the person’s life, about how many years is that? Can I get thirty years out of one bleb?

Dr. George Spaeth: I have many patients on whom I performed trabs 40 years ago who are still doing great.

P: Dr. Spaeth, Is it possible to have a trab or a shunt after having canaloplasty? What about the reverse? Does any of these automatically rule out having the other later?

Dr. George Spaeth: Any procedure that causes scarring of the conjunctiva, as does a canaloplasty or a shunt, makes future trabs hard to do.

Dr. George Spaeth: I would like to come back to the question about competence. It is a question that REALLY needs to be addressed. How do YOU decide if a doctor is competent?

P: Partially on how he/she talks to me, interacts with me.

P: What do you mean by that?

P: Does he listen? Does he like questions?

Dr. George Spaeth: I think that is on target. Doctors that don’t like to be asked questions are scary for me

P: I called Wills and asked for someone in my area who had trained at Wills.

Dr. George Spaeth: Thats a good way also.

P: If a doctor is on the staff at wills eye, does that mean he is good?

Dr. George Spaeth: No But it is a pretty good indication that he/she is good. One way that is usually not good is on the basis of the result a friend had.

P: For my cataract surgery, I googled him and found out what his annual billing are to get an idea of the number of operations he does.

Dr. George Spaeth: Those doctors that do more surgeries usually do better surgeries. Don’t be afraid to ask, “How many of these surgeries have you done?”

P: I received answers from surgeons that ranged from 12 a year to almost 200 a year!

Dr. George Spaeth: Twelve a year means one a month. That may be OK, but I would be wary. Some procedures are rare such as goniotomy, but for trabs or tubes or cataracts, the person should be doing one a week.

P: My surgeon told me he was good at doing trabs. I could not tell if this was arrogance or the truth. Most doctors do not want to talk negatively about someone else.

Moderator: There is a website,, that has a database of former Wills Residents and Fellows. You can search by location, specialty, etc.

P: He was also recommended to me by another doctor I really respect.

Dr. George Spaeth: That is probably the best way to chose.

P: I also like the fact that my doctor is teaching residents at our regional medical college/regional hospital

Dr. George Spaeth: Also a good sign.

P: Dr. Spaeth, who would you go to–a doctor who is very competent but arrogant and not inclined to answer questions, or a less experienced doctor who is open to questions and makes the patient feel that she’s a partner?

Dr. George Spaeth: Peg that is a tough choice. I would probably chose the less experience doctor. The definition of an impaired physician is one who lacks insight. Most arrogant people lack insight.

P: That’s what I did, Dr. Spaeth and it wasn’t easy.

Dr. George Spaeth: Let me know how that comes out. I think you did the right thing.

P: Dr. Spaeth, it’s off-topic, but for our newer people here, could you comment on what you consider good nutrition, and its effect on your eyes? And on your general health?

Dr. George Spaeth: Thank you. The eye is part of the body, and what is good for the body is usually good for the eyes. It is a tragic fact that most people in the US eat food that is not healthy for them; obesity is rampant; heart disease is common. A diet that contains lots of salads, fruits and vegetables, with meat and lots of olive oil makes sense.

Moderator: Do you have some closing remarks you’d like to make, Dr Spaeth?

Dr. George Spaeth: I do, thank you. But first, I hope I did not turn people off.

P: Dr. Spaeth – thank you for your time. Your answers are alway very straightforward and appreciated!

Dr. George Spaeth: Thank you.

New surgeries offer hope because they are the way better ways of treating are developed. But make sure that if you have a new surgery you really understand the risks and benefits.

Moderator: Dr. Spaeth, you are always one of the most stimulating. You give us lots to think about. Thanks for joining us.

Dr. George Spaeth: It’s always a pleasure working with you. Good night everyone.


About the Author:

The Glaucoma Service Foundation’s mission is to preserve or enhance the health of all people with glaucoma and to provide a model of medical care by supporting the educational and research efforts of the physicians on the Wills Eye Institute Glaucoma Service, the largest glaucoma diagnosis and treatment center in the country.
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