Stopping Macular Degeneration: In-Depth Doctor's Interview

How is wet macular degeneration traditionally treated?

Dr. Carl Awh: The common way to treat wet macular degeneration in 2009 is with monthly injections of medication into the cavity of the eye. These medicines block the action of a growth factor that causes the abnormal blood vessels to grow. By blocking that growth factor, the abnormal blood vessels wither away. Unfortunately, these medicines don't last that long, so we have to repeatedly inject the patients.

How does the new trial compare to these traditional injections?

Dr. Awh: In the CABERNET trial of the NeoVista EpiRad device, we are combining an injection of Lucentis -- the most commonly used drug to treat wet macular degeneration -- with a surgery. In this surgery we expose the choroidal neovascular membrane -- those are the abnormal vessels under the retina -- to a very low dose of radiation. We believe this radiation works together with the drug to destroy the vessels in a way that does not require as much repeated injection in the months to come.

Preliminary studies have shown that the radiation alone seems to be effective in damaging these vessels, but when combined with these other existing treatments, the treatment seems to be much more powerful and longer lasting.

What have you found out so far from this trial?

Dr. Awh: The trial's been going on for about a year and we're not at liberty to discuss any results. The results from the first year of the trial will probably be published in 2010, but certainly from our experience as investigators and what others have seen, some of the results have been very encouraging. We feel that there is real promise that this may offer a treatment that provides good vision to our patients with fewer injections and fewer visits to the office.

Is radiation commonly used to treat macular degeneration?

Dr. Awh: It's not common to use radiation. There have been many studies over the years looking at radiation to treat wet macular degeneration, but most of these studies have used other types of devices that expose the eye to much higher levels of radiation or that are very difficult to apply. With this particular device, the surgery, although delicate, is a fairly routine type of surgery for retina surgeons and it delivers a really small targeted dose. The exposure to the patient is virtually nothing. In fact, we were told that the amount of radiation exposure to the body from going through this procedure is less than one would get flying from New York to Los Angeles in a plane, so there are very minor amounts of radiation.

How does the procedure work?

Dr. Awh: The surgery is usually done as an outpatient, similar to what patients might go through for cataract surgery. Typically a patient has intravenous sedation, an IV started, and they're given a little medicine to relax them. Then we give them a shot to numb the eye, just like cataract surgery or other standard retina surgery. The surgery itself takes about a half an hour to 45 minutes, and during that time we enter the eye through tiny incisions and we remove a significant amount of the vitreous, the jelly that fills the inside of the eye. The vitreous, I like to say, is sort of like the appendix of the eye. It doesn't have any useful purpose and removing it does not damage the eye, but it can get in the way of some of the other procedures we need to do. We remove the vitreous and then we introduce the EpiRad device. This is a curved probe that we place carefully over the center of the macula where the abnormal blood vessels are growing. The radiation source is housed in a shielded handle. After we've gotten this in the proper location in the eye, our assistant activates the device that causes the radioactive source to go to the tip of the probe. We then hold it over the retina for a few minutes, then retract the radiation source into the handle, remove this from the eye, suture that incision and put a patch on the eye and the patient goes home. The one other thing that we do before they leave the operating room is inject the Lucentis, the ranibizumab, the drug that also works to help destroy the abnormal blood vessels. That's also done while the patient is fully anesthetized, where the eye is anesthetized, so the patient's not really aware of that additional injection.

What is the benefit of a treatment like this compared to the traditional way we treat macular degeneration?

Dr. Awh: One obvious benefit if this works, as we hope that it will, is that we can stop the monthly visits to the office. Because so many of our patients are in their 70s, 80s and even 90s, typically a visit to the office involves an adult child taking a day off of work or a friend bringing the patient to the office. The patient can't drive themselves, and so these monthly visits impact many more people than just the patient, the doctor and the staff. You know, our whole lives as retina specialists have changed in that we now see people and begin a course of treatment that requires monthly visits indefinitely.  Although we're really happy and honored to be able to give this treatment that helps so many people, logistically it's a problem because this is the leading cause of severe vision loss in Americans over 60. The population over 60 is growing, so it's really becoming an epidemic. If we can stop these monthly visits, or even reduce them, another very reasonable goal of this would be perhaps not completely eliminating the need for injections, but reducing the need for injections from 10 or 12 a year to one or two a year. That would still be a big benefit. There also have been some early findings that suggest that the visual outcome might be better. That data is too preliminary and in too small a number of patients to know that it will be continued in the larger study, but there is a possibility that a larger study will show not only equivalent visual outcomes, but possibly superior visual outcomes.

Are there any more risks to this procedure compared to the traditional treatment?

Dr. Awh: I think there probably is a little greater risk. We know that there is always a risk of infection when we put a needle in the eye, but in surgery, the instruments are larger and there is possibly a slighter, greater risk of infection, although the risk of infection seems to be small and typical with what we experience with all of our other eye surgeries. Anytime we're doing surgery in the back of the eye, there's also a small risk of retinal detachment. That risk is also present with injections in the eye, but the risk is possibly a little bit smaller with the injections. However, we're talking about one surgery compared to multiple injections. Every time we do an injection, we subject the patient to these risks, so even though the risk per injection may be small, you're doing the injection many more times.

How much longer will the study last? When do you foresee that patients can come in and have this done when they're not part of this trial?

Dr. Awh: Right now, the only patients who can receive this treatment are through the clinical trial and there are about 45 sites around the world enrolling. In Europe, the device has already received approval, and so patients in Europe can receive this treatment now. In the United States, it's a longer process because of the important need for FDA approval. This study will go on for at least another year enrolling patients. As the data is announced, depending upon the strength of the data, the FDA will make a decision about approval. I wouldn't expect any

END OF INTERVIEW

This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.

If you would like more information, please contact:

Kristi Gooden, Public Relations

Baptist Hospital

Nashville, TN

(615) 284-5446

Kristi.gooden@baptisthospital.com

www.baptisthospital.com

www.tnretina.com

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