Eye Didn't Know!

New approach to macular degeneration treatment

Did you know? Researchers at the University of Florida are testing a new compound, Compstatin, for its effectiveness in preventing complications of macular degeneration. This small protein blocks complement, which promotes inflammation in the body. It is believed that complement is involved upstream in the process which eventually leads to abnormal blood vessels forming and bleeding in macular degeneration.

Three volunteers with macular degeneration have had their eyes injected with compstatin, and they are now being monitored for side-effects. I am very interested to know the frequency that these medicines would be needed, as it is not pleasant to have medicine injected into the eye!

Did you also know? The drugs Avastin and Lucentis, both produced by Genentech, have revolutionized treatment of macular degeneration. These compounds, unlike any previous treatment, can cause regression of bleeding in the eye and improvement of vision!

Antioxidants and early Macular Degeneration

Did you know? The makers of antioxidants, including the ones used in the AREDS study, often make vague claims that these vitamins "promote eye health" and thus imply that they are needed by the general population. Yet there is NO evidence that this is so. A new report in the British Medical Journal analyzed the results of nine prospective studies involving nearly 150,000 subjects. They found no evidence that antioxidant supplement therapy decreased the incidence of early macular degeneration. Different studies looked at different substances, but included the following: vitamin A, vitamin C, vitamin E, zinc, lutein, zeaxanthin, alpha-carotene, beta-carotene, beta-cryptoxanthin and lycopene.

Did you also know? The original AREDS study (Age Related Eye Disease Study) showed that a combination of antioxidants and zinc reduced the progression of moderate macular degeneration to advanced vision loss. This is a specific indication for which ophthalmologists prescribe these supplements. This does not equal "promoting eye health" by encouraging the general population to use these supplements.

Smoke Your Way to Vision Loss

Did you know? A ten year study of 3,654 Australians has shown that current smokers have four times the risk of advanced macular degeneration compared to non-smokers! Smokers who had low levels of HDL (good cholesterol) or low fish intake had an even higher risk. Read more here.

(image courtesy wikipedia commons)

Did you also know? Many doctors prescribe vitamins to prevent macular degeneration, but fail to inquire about smoking habits. The risk of vision loss from smoking is an order of magnitude higher than the risk from a diet low in antioxidants, zinc, lutein and zeaxanthin.

More Macular Degeneration-Nutrition News

Did you know? There's clearly more to the macular degeneration/nutrition link than what is on the radar screen of most ophthalmologists. A new study showed that vitamins B6, B12, and folate may be protective. A group of over 5000 women at risk for heart disease was randomized to placebo or Vitamin B6, B12 and folate. After seven years, the group taking the vitamins had 41% less visually significant macular degeneration.

Did you also know? The study was designed to assess whether these vitamins would lower heart disease (by lowering homocysteine levels). There was NO difference in heart disease in the two groups!

Fishy news

Did you know that eating fish may help prevent macular degeneration? Two studies in this month’s Archives of Ophthalmology showed that advanced macular degeneration occured less often in those who ate fish regularly compared to those that ate fish rarely. One study examined the eyes and took a dietary survey of over seven thousand subjects. Those who ate fish at least weekly had less than half the prevalence of advanced macular degeneration compared to those who ate fish less than twice a month. Another study showed a 35% decrease in advanced macular degeneration for those who ate more broiled or baked fish (but not fried!). The authors postulate that fish oils may decrease inflammation and decrease the formation of abnormal new blood vessels, both of which occur in advanced macular degeneration. Whether or not fish-oil supplements are helpful in macular degeneration is not known.

(image courtesy wikipedia commons)

Did you also know? The first of these studies also found that drinking milk was related to less early macular degeneration. (Possibly related to its vitamin D content.)

(image courtesy wikipedia commons)

New use for old Chinese remedy?

Did you know? A synthetic version of bear bile, used in Chinese medicine for millenia, is being tested for its ability to prevent cell death which occurs in macular degeneration, glaucoma, and retinitis pigmentosa. TUDCA and UDCA are components of bile, which help us digest fats. Humans have small amounts of these compounds, but bear bile has large amounts. Synthetic versions are available and inexpensive. Researchers at Emory University tested these compounds. When injected into mice, they preserved the function and structure of retinal cells in two different mouse models of human retinal degeneration. Read about it here.

Did you also know? The researchers stress that the compounds they are testing are synthetic, and do not involve harvesting bear bile! In fact, UDCA, or ursodiol, is available orally as a treatment for liver disease.

Beta Carotene and Macular Degeneration

Did you know? A new study has been released in Archives of Ophthalmology, which followed over 22,000 male physicians for twelve years. Half were randomized to take beta-carotene supplementation, half took a placebo. There was NO statistical difference in the incidence of macular degeneration between the two groups. Supplementation had neither a beneficial or harmful effect. This study is notable in its rigorous design, number of subjects, and length of follow-up. The authors are among the most respected in the field of ocular epidemiology.

Did you also know? The well-known AREDS study looked at supplementation with high doses of zinc, beta-carotene, and vitamins C and E. This study showed a modest benefit for those with a high-risk of macular degeneration, (those with significant drusen in their maculas), but no measurable effect for those with no risk factors, since the risk for these patients was low to begin with.

Macular Degeneration Eyedrops?

Did you know? A Virginia company, Ocucure Therapeutics, is attempting to develop an eyedrop which could inhibit or reverse the damage caused by macular degeneration. In the wet form of macular degeneration, abnormal blood vessels form in the back of the eye, leading to bleeding, scarring, and vision loss. A complicated molecular cascade triggers this process. Ocucure has developed a treatment based on inhibiting tubulin, which is a cellular component involved in blood vessel formation. The company claims that this treatment works in animal models, and penetrates into the eye in an eyedrop form. Human trials await.

Did you also know? If this therapy should prove to work for macular degeneration, then it would also have a potential use in diabetic retinopathy, also caused by abnormal blood vessel formation.

Macular Degeneration Highlights

Did you know? A recent Forbes Magazine article highlights the recent rush by pharmaceutical companies to develop treatments for macular degeneration. Most notable are two nearly identical treatments produced by the same company, Genentech. These treatments, called Lucentis, and Avastin, both inhibit vascular endothelial growth factor, or VEGF. Both treatments are injected into the eye and cause inhibition and even regression of abnormal blood vessels in the retina which are a primary cause of vision loss in macular degeneration. Both treatments work, and signal a new era in treatment for macular degeneration.

Did you also know? There is a huge controversy brewing in ophthalmology. Lucentis, FDA approved, costs about $2000 per injection. (injections may be needed on a monthly basis). Avastin, not yet FDA approved for this indication, costs less than $50 per injection (because it is made in large quantities for colon cancer). Genentech has NO plans to compare the two drugs, and needless to say, does not advertise Avastin for this use. The National Eye Institute, however, is conducting a head-to-head trial, and smaller trials will likely be performed.

Macular Degeneration Genes

Did you know? A mutation in a gene called Complement Factor H increases one's risk of macular degeneration by four times. Complement Factor H is normally involved in limiting the inflammatory response in the body. When this gene is abnormal, there is more inflammation. This shows that inflammation is involved in macular degeneration.

Did you also know? Another gene, called LOC387715, when abnormal, also increases the risk of macular degeneration. If you have these two genes, and smoke, your risk increases 50 times! Read more here.

Exercise and Macular Degeneration

Did you know? Exercise may protect against macular degeneration. A recent study of nearly 4,000 subjects, published in the British Journal of Ophthalmology, showed that those with a sedentary lifestyle were three times more likely to have a severe form of macular degeneration than those with an active lifestyle. That is a very large difference (much larger than the small protective effect of Ocuvite or similar vitamins for macular degeneration)!

Did you also know? It is well established that smokers have two to three times the risk of macular degeneration than non-smokers. Although many therapies are under investigation for macular degeneration, none is effective as prevention-- the best medicine!

Lutein and Zeaxanthin?

Did you know? The nutrients lutein and zeaxanthin are found within the macula of the human eye, the area responsible for fine vision and the area damaged in macular degeneration. They are pigments, and may serve to protect against damage from light and oxidation. These pigments are found in high quantities in green leafy vegetables, such as spinach. Population studies have shown that those with higher dietary intake of these pigments have less macular degeneration. There is no evidence yet that taking supplements has a protective effect.

Did you also know? A large clinical trial, called AREDS II, (Age Related Eye Disease Study II), is investigating the use of lutein and zeaxanthin supplements, as well as the role of omega III fatty acids, in macular degeneration. The five year study began in 2005, so we will all eagerly await its results. Read more here: lutein and zeaxanthin here: AREDS I or here: AREDSII