Zinc and AMD.

Rationale:

Zinc and antioxidants supplementation can delay the
progression of age-related macular degeneration (AMD). Compared to
controls, AMD patients have a higher level of complement-mediated
inflammation as demonstrated by subretinal complement deposits (drusen).
The AREDS study has demonstrated that zinc supplementation may prevent
the progression of AMD and preserve visual function in 21 % of patients.
In addition, it has been demonstrated that zinc has the ability to
temper activation of the complement cascade by direct binding to active
complement molecules.



Objective:

1. To determine if zinc supplementation in AMD patients has a
direct measurable effect on the complement system explaining the
mechanism through which this substance exerts its influence on AMD
progression;

2. To determine whether this proposed effect of zinc is influenced
by the genetic status, regarding the Y402H and ARMS2 polymorphism,
enabling us to identify subgroups of patients more susceptible to the
beneficiary effect of zinc.



Study design:

80 AMD patients will be enrolled. These groups will
receive 50 mg oral zinc supplements during 3 months. Serum level of
complement component C3 and activation fragments C3d will be analyzed
prior, during and post treatment.



Study population:

80 AMD patients of 50 years of age or older with
extensive small, intermediate, and large drusen, geographic atrophy
and/or exudative AMD but without active disease as demonstrated by
active neovascularisation, will be recruited for the study.



Intervention:

All participants of the study will receive daily oral 50
mg zinc as zinc sulfate and 1 mg copper as cupric sulphate for 3 months.
The reason for the presence of a small amount of copper is based on the
fact that zinc and copper compete for the same membrane transport
systems. The ratio zinc to copper in the present preparation reflects
the physiological situation. The same reasoning has also been followed
in the Age-Related Eye Disease Study (AREDS) of the National Institutes
of Health in the US.

To determine if zinc supplementation in AMD patients has a direct measurable effect on the complement system explaining the mechanism through which this substance exerts its influence on AMD progression.

Serum level of complement component C3 and activation
fragments C3d will be analyzed prior, during and post treatment.

All participants of the study will receive oral 50 mg zinc as zinc sulfate and 1 mg copper as cupric sulphate dailly for 3 months.