Newest Treatments for Age Related Macular Degeneration

Overview
Newest Therapies
Lucentis
Avastin

For over three decades, standard laser therapy was the only viable treatment for patients with wet age-related macular degeneration (AMD). This treatment, while a great breakthrough in its day, had extreme limitations. Only about 25% of patients with wet AMD were candidates for this treatment, and of those treated, about 50% would experience some form of recurrence of the disease. Almost none of the patients who were treated with laser experienced improvement of their vision, and in most cases slowing or stabilization of the disease was the best one could hope for. Occasionally, we still recommend standard laser treatment for our patients, but in most cases, we will utilize one of our newer and more effective therapies.

If you have "wet" AMD affecting the middle of the macula, in some cases, photodynamic therapy (PDT) is possible. This treatment involves infusing a light sensitive drug (Visudyne) through your blood stream similar to a fluorescein angiogram. This drug is able to identify the new blood vessels, growing in the wrong place behind the retina, that form with "wet" AMD. A "cold laser" is then shone into the eye which activates the drug stopping the new blood vessels from growing and helping to prevent them causing too much damage to the macular area. The "laser" does not burn the retina as it treats, thereby limiting any harm to normal retina. This treatment has been shown to be effective for some people with certain types (i.e. "classic) "wet" AMD, but generally only improves vision about 5% of the time. It generally slows the process of visual loss, and requires repeat treatments, often about 3-5 treatments in the first year. See article entitled "Photodynamic Therapy" for more information about this therapy.

Newest Therapies:

The newest treatment modalities for wet AMD do not utilize any sort of laser. These treatments are in a class of drugs called "Anti-VEGF" therapy. VEGF stands for Vascular Endothelial Growth Factor, and it is a protein that is important in forming new blood vessels. This process can be useful in healthy individuals when new blood vessels are needed, such as during wound healing or after a heart attack, for example. In certain disease states, however, abnormally high concentrations of VEGF can lead to damage by the growth of new blood vessels where they shouldn't be, such as under the macula in the wet form of AMD. This new class of drugs acts by blocking VEGF and preventing it from stimulating the growth of these abnormal blood vessels.

These drugs need to be administered by injection into the vitreous cavity (the center part of the eye). This is considered a minor procedure and it can be performed in the doctor's office. Although this sounds awful, almost all patients tolerate this procedure extremely well. After the eye is anesthetized, most people feel no pain, only slight pressure as the medicine is injected. In general, the injections are very safe, with only a very small risk of ocular side effects. In most cases, repeat injections are needed.

The first new drug developed was called Macugen and was released in early 2005. It was truly a breakthrough in that it was the first in its class and allowed us to treat most forms of wet AMD for the first time. Its major limitation, however, was that it even though it worked better than previous therapies (i.e. PDT and laser), in the majority of cases, it still only slowed the disease and required repeat treatment every six weeks indefinitely. More effective therapies are now available and Macugen is seldom utilized anymore.

Lucentis

LUCENTIS™ (ranibizumab injection), was approved by the FDA at the end of June 2006 for use in wet AMD. The initial results of a phase III study utilizing Lucentis were reported in the summer of 2005. The data reported demonstrated for the first time a significant chance of improving vision in those patients recently affected by wet AMD. The data actually demonstrated a 40% chance of vision improvement at 1 year of therapy. It also demonstrated a 95% chance of at least vision stability at 1 year. For the best results, usually multiple injections are needed on a monthly basis for at least 1 year. The frequency of injections can be varied to some extent by your physician depending on your particular condition, but the results, while still good, may not be as strong. The safety concerns of Lucentis injection are small. There are some limited side effects associated with the injection itself, including a rare chance of infection (about 1/1000), cataract or retinal detachment. Most of these side effects are treatable and in most cases did not limit continuation of therapy. While Lucentis therapy is new, there were no significant systemic side effects noted. The study suggested that there might be a trend toward an increased risk of thromboembolic events (i.e. stroke), but this trend was not statistically significant. More information regarding Lucentis can be found at Lucentis.com.

Avastin

Following the reported benefits of Lucentis therapy in the summer of 2005, retina specialists turned their attention towards Avastin, which is a medicine currently FDA approved for the treatment of metastatic colon cancer. Avastin is molecularly similar to Lucentis and acts in the same way by binding the protein VEGF. The medicine helps control metastatic cancer by blocking the blood vessel growth required by new tumors to grow and spread. This is the similarity to wet AMD in that new blood vessels grow underneath the macula.

Since Lucentis wasn't available outside of clinical trials until this summer, Avastin has been used for the past year with very promising results. There have been a limited number of studies published that demonstrate a beneficial effect, but its true efficacy is still unknown. There has been no direct comparison of Avastin against other therapies. Although it is believed Avastin is safe, there is no good controlled study data to confirm this.

Your physician may recommend using Avastin for your wet amd condition, but it is considered "off-label" which means this use (in wet amd) has not been evaluated by the FDA. Just because a therapy is "off-label" does not mean it shouldn't be used, but a thorough discussion with your physician is required to confirm that this is the best of available therapies.