However, they discovered that a majority of patients lack a clear understanding of supplement use in AMD treatment. The researchers found that almost 40 percent of those who appeared to benefit from specific vitamin/mineral supplements were either not taking the supplements or not using the recommended dosage.
Also, it indicated that some patients used high-dose supplements even though there was no evidence that these would be effective for their levels of AMD or other eye conditions.
Headed by Susan B. Bressler, M.D., the ophthalmic researchers said that most of the AMD patients do not have a clear understanding of supplement use in AMD treatment, and that "improved patient education may be vital to maximize the potential" of this therapy.
They said that the public health impact due to this lack of knowledge could be substantial, and if proper supplements are incorporated, one can ward off advanced AMD which can destroy the central vision needed to recognize faces, read, drive and enjoy daily life.
A clinical trail in 2001 by the Age-Related Eye Disease Study (AREDS) identified a specific formula of antioxidants (vitamin C, vitamin E and beta-carotene) and zinc that reduced the likeliness of progression to advanced AMD by 25 percent, either the "wet" or central geographic atrophy forms, among individuals at risk.
Those having AMD and also smoke are required to use a formula that omits beta-carotene since high doses of this micronutrient have been linked with increased rates of lung cancer and mortality.
While effective treatment for advanced AMD is available, it can be expensive and is limited to the "wet" form. Besides, since such treatment may not restore vision already lost to the illness, it is still vital to use all effective approaches to preventing AMD progression.
For the study, the researchers surveyed 332 individuals who identified themselves as having AMD, with the median participant age of 79 years. Out of these, 228 were considered candidates for benefit from the AREDS formula.
However, only 140 patients (61 percent) in this group were using the correct formula as recommended. They found that almost 50 percent of the candidates-for-benefit did not correctly answer questions on the relevance of vitamin/mineral supplements to their eye condition and how their vision might benefit.
On the other hand, patients who indicated that they partially or fully understood the rationale for supplements were about twice as likely to be using the AREDS formula correctly.
The study is published in the latest issue of Ophthalmology, the journal of the American Academy of Ophthalmology.