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Preventive AMD Treatments
14
A better understanding of the pathophysiological processes
occurring in “retinal aging” and age-related macular degen-
eration (AMD) has been achieved in recent years, leading
to the emergence of new treatments and consequent long-
term improvements in the quality of life of patients.
AMD is one of the leading causes of severe, irreversible
vision impairment in developed countries, in individuals
over 50 years of age.
Approximately 1.75 million people over 40 in the United
States suffer from neovascular AMD or geographic atro-
phy; 7.3 million patients display large drusen (≥125
microns) in one or both eyes
(1)
.
In the United States, AMD causes approximately 46% of
severe visual loss cases (visual acuity of 20/200 or worse)
in patients over 40
(2)
.
Although, an estimated 80% of AMD patients display the
non-neovascular form of this disease, the neovascular form
is responsible, for almost 90%, of cases of severe visual loss
(visual acuity of 20/200 or worse) caused by AMD
(3)
.
Data from three population-based studies – the Beaver
Dam Eye Study, the Rotterdam Study and the Blue
Mountains Eye Study – have led to an estimated preva-
lence of advanced AMD of 0-2% in patients aged 55–64,
increasing to 13% in patients over 85
(4)
.
Since there is no significant cure for AMD, prevention
may be the first and logic approach to reduce vision loss,
justifying an intensive search for some kinds of interven-
tion able to prevent the onset of AMD or to delay its
progression to more advanced and severe forms.
Age is the main risk factor for AMD; all population-
based studies confirm that the prevalence of AMD
increases with age in white individuals
(5,6,7)
.
Belonging to the female gender may also constitute a risk
factor in individuals aged over 75 years
(8)
.
Several studies also demonstrated that effective control
of modifiable risk factors, such as smoking, hypertension
and body-mass index, could reduce the risk of develop-
ing AMD by half
(9)
.
Since the early 90’s, when “large population studies”
appeared, several hypotheses have been formulated
around the idea that nutritional supplements such as
antioxidants, vitamins and/or minerals may be able to
reduce the risk of AMD development.
2. AREDS (Age-related Eye Disease
Study)
2.1 AREDS 1
2.1.1 Design implications and study categories
AREDS (Age-related Eye Disease Study) was a prospec-
tive, multicentric, randomised clinical trial conducted
between 1992 and 2006, mainly sponsored by the
National Eye Institute (NEI) of the National Institutes
of Health (NIH). This study was designed to evaluate the
clinical aspects, natural course and risk factors associated
with age-related cataract and AMD, as well as the effects
1. Introduction
Authors:
Maria João Veludo, MD
1
Filomena Costa e Silva, MD,
2
Susana Teixeira, MD
2
1
Lisbon Hospital Center - Lisbon, Portugal
2
Prof. Dr. Fernando Fonseca Hospital, Amadora, Lisbon, Portugal
