Manchester Research Adds Further Support To Nutritional Strategy
For Eye Health
Manchester,
England, 19 August 2002
Age-related
macular degeneration (AMD) is the most common form of macular disease.
It leads to loss of central vision and is the principal cause of
irreversible blindness in the elderly.
Evidence
has been growing in recent years that a tiny part of the eye's retina,
termed the macular pigment, may give the eye in-built protection
from the degenerative disorder. Research findings strongly indicate
that people are at greater risk of developing AMD if the density
of their macular pigment is low. The macular pigment is entirely
made up of lutein and zeaxanthin, plant pigments found in many fruits
and vegetables. Research groups around the world are excited by
the prospect that it may be possible to increase macular pigment
density and thereby reduce the risk of the disease developing, by
simply adding extra lutein and zeaxanthin to the diets of those
at risk. However, this work is not yet complete and the case has
yet to be proved.
New
research by Dr. Ian Murray and his group, from the Department of
Optometry and Neurosciences at the University of Manchester, has
provided further evidence in support of this theory. It has also
raised the possibility that patients already experiencing early
stages of AMD may even be able to delay or prevent its progress
through similar dietary intervention. The work is supported by the
UK Department of Health under the MedLINK programme (the LINK programme
for medical devices).
Dr.
Murray, who presented his group's latest findings to the annual
meeting of the Association for Research in Vision and Ophthalmology
in Florida, says: "I have seen many patients who are suffering from
the disabling effects of AMD. Of course we are excited by the prospect
that a simple addition to the diet may impede the progress of the
disease and prevent others who are at risk, experiencing such problems.
Right now, dietary intervention is the only hope for most of them".
In
one study, Dr. Murray's group selected 8 patients at an early stage
of development of the disease. Aged between 60 - 81, these patients
so far have normal visual acuity. They were compared with 'normal'
subjects, matched for sex, eye-colour and age. The researchers observed,
as in earlier studies, that eyes at risk of developing early-stage
AMD (because of AMD symptoms in the fellow eye) have lower macular
pigment density than eyes without such risk, adding credibility
to the theory that the macular pigment has an AMD-protective role.
In
the second - ongoing - study, the researchers gave a daily supplement
of lutein (in the ester form) to 8 patients (6 from the first group)
and to 8 normal subjects, over a period of 18 weeks and measured
the effects.
Interim
data, after 12 weeks of supplementation, indicate that the density
of macular pigments in both patients and normal subjects increased
at the same rate. Further, the researchers found that, where patients
already had AMD in one eye, both eyes responded equally well to
supplementation.
The
researchers' conclusion is that the disease does not stop lutein
from being deposited in the retina, at least in the early stages
of AMD. Based on the theory that higher macular pigment density
protects against retinal damage, the corollary of this finding is
that dietary intervention may be beneficial for those with early
stage AMD as well as those considered at risk of developing the
disease.
For
more about AMD, visit www.ucl.ac.uk/ioo/links.htm.
Source
University
of Manchester
Contact
Dr. Ian Murray at Department of Optometry and Neuroscience. Tel:
+44 (0)161 200 3862, E-mail Ian.murray@umist.ac.uk.
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