News from The Retinal Society Meeting

News from The Retinal Society Meeting in San Diego
September 19, 2005

I just returned from the annual meeting of The Retinal Society in San Diego. The Society consists of an elected group of retinal specialists within ophthalmology. One of the main topics was the use of Avastin® intraocularly to treat the wet form of AMD. Let me recap the reasoning behind intraocular Avastin®:

In the July 19th blog I summarized the results from the MARINA Study that had just been announced at the meeting of the American Society of Retinal Specialists in Montreal. The MARINA Study tested the use of Lucentis® intraocularly for the treatment of the wet form of AMD. At 12 months, the patients who received Lucentis® gained 7 letters of vision compared to a loss of 10.5 letters in the control group. This 17 letter difference between the treatment and control groups represents over three lines on the visual acuity chart. In addition, forty percent of the patients who received Lucentis® had 20/40 or better vision at 12 months! This was the first treatment for the wet form of AMD that resulted in improved vision and the results were much better than the results for either Macugen® or Visudyne®.

Lucentis® is a smaller active molecule cleaved from the larger molecule, Avastin®. Genentech made the smaller molecule because they believed that Avastin® was too large to pass through the retina. Retinal specialists were frustrated because some of their patients were not responding well to Visudyne® or Macugen® and because Lucentis® is not yet FDA approved. So they tried Avastin®. Intravenous Avastin® worked very well for treating the wet form of AMD but has some potential severe side-effects such as stokes and heart attacks so a few retinal specialists injected much smaller amounts of Avastin® directly into the eye.
So far, probably about 500 patients with the wet form of AMD have received injections of Avastin®. Intraocular Avastin® appears to work very well at stopping the growth and leakage of the new blood vessels in wet AMD. There have been no signs of toxicity or side-effects but most of these patients have been followed for only a few months. Most retinal specialists recommend Avastin® only after Visudyne® or Macugen® treatments, both of which are approved by the FDA, have failed to control the new blood vessels.

What should you do now if you have or know someone who has wet AMD? I think an initial treatment with Visudyne® or Macugen® is reasonable. Usually an injection of intraocular Kenalog® is given with Visudyne® because it appears to improve the prognosis. If this initial treatment doesn’t work, say after one Visudyne® treatment or two injections of Macugen®, I think it would be reasonable to talk to your doctor about Avastin®.
This is what we know as of September 19, 2005. We will learn much more in the next year as patients are followed for longer periods of time and from the many clinical trials that are being performed on wet AMD.

Please stay in touch to keep up to date. As always, I welcome your questions.

What you can do to reduce your risk of Macular Degeneration

Over the last few weeks, we have discussed nutrients that reduce the risk of AMD. Here is what else you can do to reduce your risk of AMD listed in order of importance:
1. Quit smoking. Most studies show that smokers have a two to four times greater risk of developing severe AMD than nonsmokers. This is two hundred to four hundred percent! Compare this to a 25% percent reduction of AMD if you take the AREDS supplements. Smoking is by far the biggest risk factor that you can control.
2. Control your blood pressure. Doctors used to believe that a blood pressure of 150/90 was in good control. Patients with AMD should shoot for a blood pressure of 140/80 or lower.
3. Lose weight until you are in the normal range. Fat, especially fat around the middle, seems to increase the risk of AMD.
4. Get your cholesterol checked. If it is high, take a drug from the statin group. Statin type drugs that are currently on the market include: atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), and rosuvastatin (Crestor). There is good evidence, but not yet proof, that these drugs may reduce the risk of AMD and also of Alzheimer’s disease.
5. Protect your eyes against excess light by wearing a hat with a brim and good sunglasses. The hypothesis that light toxicity causes AMD has lost support recently but it still makes sense to protect your eyes.