Rapid Responses to:
|
|
Rapid Responses: Rapid Responses published:
-
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
Dietary antioxidants in AMD
- Sachin M Salvi (15 October 2007)
-
A Timely Article
- Jeffrey Sandler (3 November 2007)
|
|
|||
|
Sachin M Salvi, Specialist Registrar Department of Ophthalmology, Royal Hallamshire Hospital, Glossop road, Sheffield S10 2JF
Send response to journal:
|
Dear Sir, I read with interest the review article published by Elaine W-T Chong et al(1). I have one concern and one suggestion. Their review shows that there is insufficient evidence to support the role of dietary antioxidants, including the use of supplements for primary prevention of early AMD (age related macular degeneration). But the database mainly consisted of patients coming from relatively well nourished patients from developed western countries. We already know that in patients who have a well balanced diet rich in green leafy vegetables, vitamin supplements may not be necessary. Thus this group of "well nourished" patients do not need dietary anti-oxidants as they already receive it in their proper diet. But there is a whole group of patients in clinical practice who on history taking and physical examination do not appear to have a balanced diet(maybe because they come from a different socio-economic background) and are also at a risk of AMD. This is where problems can arise. My concern is if we take the conclusion drawn by the present study on face value and stop advising patients on the basis of insufficient evidence about need for a well balanced diet and in patients who do not have a well balanced diet, the need for dietary anti-oxidants or supplements. There is a potential that we may miss emphasising a preventive measure for AMD which has the potential for devastating visual loss. Also AREDS study(2) has shown a 28% reduction in the risk of progression to advanced AMD compared to placebo by treatment with high dose anti-oxidants supplement. We also know that genetic markers are a risk factor(3). So it may be possible that anti-oxidants treatment may have a role to play in prevention of AMD in the relatives of patients who have suffered from AMD. My suggestion is that a randomised control trial looking at diet patterns and dietary anti-oxidants and supplements in close relatives of AMD patients may shed further light on this subject. References: 1. Chong E W-T, Wong TY, Kreis AJ, Simpson JA, Guymer RH. Dietary antioxidants and primary prevention of age related macular degeneration: systematic review and meta-analysis BMJ 2007; 335: 755 2. Haines JL, Hauser MA, Schmidt S, Scott WK, Olson LM, Gallins P, et al. Complement factor H variant increases the risk of age-related macular degeneration. Science 2005;308:419-21. 3. Age-Related Eye Disease Study Research Group. A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss: AREDS report No 8. Arch Ophthalmol 2001;119:1417-36 Competing interests: None declared |
|||
|
|
|||
|
Jeffrey Sandler, Ophthalmologist 4699 Main Street, Bridgeport, CT 06606
Send response to journal:
|
I read your article with great interest. This past week, a patient came to me for a second opinion. Her optometrist had urged her to undergo "ZeaVision QuantifEYE" testing - for which she would have to pay an out of pocket fee. The "test" states it is "a measurement of Macula Pigment Optical Density (MPOD)." It goes on to say, " eye care professionals now have the ability to assess risk for AMD, take a proactive approach by providing a professionally formulated supplement to help reduce the risk for developing this debilitating disease." The company that sells the machine conveniently sells the dietary supplement to the providers, who then sell them at considerable cost to the patients who show "low macular pigment." Finally, they state, "With MPOD testing and supplemental intervention, it is possible to increase the pigment levels in your macula, thus lowering your risk for vision loss." (zeavision.com) None of the "research" cited supports a benefit of treatment; not surprising given your findings. I have forwarded your study to the company and await their reply. Competing interests: None declared |
|||