Micronutrients in other macular diseases

I have received questions that ask whether the vitamins and lifestyle recommendations for AMD apply to other diseases such as Best Disease and Myopic degeneration.

Best Disease is a macular dystrophy that usually affects young or middle-aged patients and is characterized by a yellow vitelliform (egg-like) lesion in the macula. Best disease is caused by a mutation in bestrophin, a protein necessary for transport of chloride in the retinal pigment epithelium. The retinal pigment epithelium, or RPE, is the layer of cells immediately beneath the photoreceptors and is vital for visual function.

I asked my colleague, Dr. Edwin Stone, the world’s expert on Best Disease, whether there was any plausible reason to recommend vitamins for these patients. He said that there was no reason to believe that they would help and that he didn’t recommend any nutritional supplements for patients with this disease. He pointed out that nutritional supplements can be harmful such as the increased rate of lung cancer in smokers who took beta-carotene.

Dr. Stone believes however, that eyes with Best disease are prone to bleed beneath the retina after trauma. He therefore recommends that patients with this disease protect their eyes with goggles when engaging in sports where the eye could be struck with a ball or inadvertently by an opponent.

Myopic degeneration is caused by a large eyeball which causes a stretching and thinning of the retina, choroid, and sclera. It usually starts in middle-age with round areas of RPE atrophy and lacquer cracks in Bruch’s membrane beneath the RPE. The degeneration is roughly associated with the degree of myopia however some patients with very high myopia get minimal degeneration whereas others with less myopia have severe changes. It seems reasonable to me that AREDS-type vitamins may reduce the stress to the outer retina and retard the progression of myopic degeneration. There are no studies that have tested nutritional supplements in myopic degeneration however, and many of my colleagues disagree with me. I recommend to my patients who have myopic degeneration to at least take a multivitamin a day or perhaps half of the AREDS dose. This recommendation “splits the difference,” so to speak, yielding a possible benefit while reducing the risk of unknown side-effects from the full AREDS dose over many years.

References:

1. Stone E, Nichols, B, Streb L, Kimura A, Sheffield V, “Genetic Linkage of vitelliform macular degeneration (Best Disease) to chromosome 11q13” Nat Genet. 1992;42:156-159,

2. Petrukhin K, Koisti, M, Bakall B, et al. “Identification of the gene responsible for Best Macular Dystrophy” Nat Genet. 1998;19:241-247

Intravitreal Injections for the Treatment Age Related Macular Degeneration

We have discussed a lot about intravitreal injections for the treatment of neovascular AMD so I thought it would be worthwhile to show you a video showing how we do these injections at Iowa. Please let me know if you would like to see videos of other types of treatment.

View Full-Size Intravitreal Injection video on Google Video.

AREDS II in the Works

In June of this year, I talked about vitamin supplements that retard the progression of AMD. This new and important information was discovered by the Age-Related Eye Disease Study (AREDS I). The last blog, which stated that cataract surgery doesn’t appear to increase the progression of AMD, was also information gained from AREDS I.

Now the National Eye Institute is recruiting clinical sites to begin AREDS II. Findings from epidemiologic studies as well as AREDS I showed that patients with reduced dietary intakes of lutein and zeaxanthin and omega-3 fatty acids had an increased risk of AMD (see also the August 4th blog, www.medrounds.org/amd/2005/08/lutein-zeaxanthin-and-omega-3-poly.html). AREDS II will test whether supplementation with a combination of 10mg of lutein and 2mg of zeaxanthin a day and/or one gram of omega-3 long-chain polyunsaturated fatty acids will decrease the risk of progression of AMD.

In AREDS I, a large dose of zinc (80mg/day) was used. High doses of zinc can cause prostate enlargement. There is also laboratory evidence that zinc can increase the risk of Alzheimer’s disease, however no such connection was found in AREDS I. AREDS II will compare the results of patients given 80mg/day of zinc to patients given 40mg of zinc per day.

Two large studies showed that supplementation with beta-carotene increased the risk of lung cancer in smokers. Therefore AREDS II will also test whether removing the beta-carotene reduces the efficacy of the combination of vitamins and minerals used in AREDS I.

Once AREDS II is up and running, I would encourage patients with AMD to join the study. You will be advancing our knowledge of AMD and also be “in the know,” so to speak, of any new developments.

Many of you may think, “Why don’t I just take this supplements and not bother to join the study?” If you do this, we may never know whether these supplements work. Taking unproven supplements is also potentially dangerous. The information about lutein, zeaxanthin, and omega-3 fatty acids came from dietary questionnaires. No one knows if oral supplements will have the same protective effect. In addition, AREDS II could show no benefit or even a harmful effect of these new supplements. If you were a smoker and just decided to take beta-carotene on your own, you would have exposed yourself to a higher risk of lung cancer. That’s why we need patients to join AREDS II and answer these questions as quickly as we call. It’s the right thing for you to do.

See also: The Age-Related Eye Disease Study II (AREDS II) will begin soon after the initial AREDS concludes in January 2006.

Compounding Pharmacies

I received this e-mail from a compounding pharmacist and thought I should pass it along to you. I have no financial interest in this or any pharmacy.
JCF

My name is Tim Dannehy and I am a compounding pharmacist at Fallon Wellness Pharmacy in Latham, NY. I was happy to see your blog re:797 standards for sterile compounding. According to the standards a 45 day expiration date may be given to a low risk compound i.e. Avastin if the product passes a sterility test. I recommend that physicians ask their pharmacy for a copy of these sterility results and insist that they are done by an outside lab. Current in house testing kits only test the product in one medium (tryptic soy broth). This medium does not support the growth of all organisms, therefore, a negative result does not ensure absolute sterility.
Any pharmacy that is giving their product an expiration date past 14 days without an outside lab sterility test is putting the patient, the physician and themselves at risk. We have just started our Avastin program and will have our product tested by a 3rd party in order to give it a 45 day expiration. I would love for our pharmacy to be on your recommendation list. Our information is as follows:
Fallon Wellness Pharmacy
1057 Troy-Schenectady Rd.
Latham, N.Y. 12110
Phone 1-800-890-1137 ext. 110 or
518-220-9008 ext.110
Fax 518 220-5004
NYS Board of Pharmacy Phone 518-474-3817 ext. 130