Although AMD is a leading cause of blindness in the elderly, its pathogenesis is not clearly understood. In recent years, there has been increasing interest in the potential role of antioxidants and maculta pigment in AMD pathogenesis. I work closely with an opticians group and online retailer eyebuddy who supply Macushield (there are many other suppliers and vitamins too!) and have spoken to the UK Licensee, the 2 UK suppliers, many optical professionals and customers who use it so thought i would share my thoughts for what they are worth. I don't want this for personal gain but I have AMD in the family and it is a serious topic. I am quite used to reading research (PhD) and read a fair amount around the topic and have been close this product for well over 2 years now.

From a personal point of view i think it is always worth viewing things described as "miracle cures" cynically as they usually are more often than not just media hype. The USP (unique selling point) claim of Macushield and where all the hype comes from is its inclusion of Meso-zeazanthin (MZ) which is considered by many to be most important anti-oxidant for the macula. It is therefore the MZ that separates it from other AMD vitamins. Early studies (linked to the manufacturer I should add) indicated that this helped to boast the density of macular pigment, which is very encouraging assuming this is confirmed by other studies. [b]HOWEVER[/b], there is also a counter argument here that i haven't seen anyone else mention, which is that 'Lutein', which is found in other vitamins and leafy green foods etc, is used by the body to make it's own MZ. If this is the case, it is hard to know if taking MZ directly is of any benefit and you can typically find Lutein only vitamins for a fraction of the cost. There is evidence though that some people with AMD lack the enzyme to convert lutein into MZ efficiently themselves.

The AREDS study was one of the first clinical trials that established the key role of oxidative stress in AMD pathogenesis. Results showed that people with high risk of AMD, lowered their risk by about 25% when created with high-dose combinations of vitamin C, vitamin E, beta-carotene and zinc. Since this study, several epidemiological studies have supported the different formulations, including antioxidants but this does not imply a ‘cure' as such. A new larger phase 3 of randomized clinical trials (sponsored by the National Eye Institute) has begun looking into Lutein/Zeaxanthin and Omega-3.

Within the media, one day you read that AMD vitamin supplements in general have no effect and then the next minute they are miracle cures. We have had little feedback from those that have found no effect although most people are unlikely to feed this back. However, i am pleasantly warmed as to the anecdotal evidence similar to Harry's case where customers (or more often relatives) taking Macushield have had very positive results and fed back to me. If this is true and not skewed by another factor (e.g., change in lifestyle, diet, smoking, a placebo effect etc), this has got to be a good thing for perhaps slowing progression, and better still, working towards a reversal. I think prevention is the more likely benefit than cure although interesting most people see it as the cure. Either way, i do think that if you are taking Macushield, or any other vitamins for that matter, you should not have high expectations but just hope to be pleasantly surprised.

Without a doubt in my view, the key to a healthy macula is most importantly to stop smoking (if you do), eat well focusing on a lower cholesterol diet and getting your 5 fruit and veg a day and preferably some fish each week. Genetics plays a big part too by the looks of things but clearly you can't change these easily! Vitamins are just supplements and should be seen as purely that and not a 'miracle cure'. Let's hope some of the studies on-going in Limerick show positive outcomes though.