Research

Most individuals with ARMD have a progressive degenerative change of both eyes due to damage to the retinal pigment epithelial (RPE) layer under the macula; this termed dry degeneration. Less than 10% of those individuals will progress to choroidal neovascularization resulting in exudation and/or hemorrhage of the macula, wet ARMD. The critical role of the RPE in ARMD is recognized by heroic attempts to move the macula to areas of healthy RPE with macular translocation surgery. Additionally, very recent and limited trials with embryonic stem cells repurposed as RPE cells have been initiated in advanced dry ARMD.

Significant strides have been made in the treatment of wet ARMD – namely intraocular injection of medications that can inhibit the growth of the offending new blood vessels. However, the treatment of dry ARMD has been limited to nutritional therapy. The nutritional therapy is based on the knowledge that there is declining anti-oxidant function in the aging eye. Normal functioning of the retinal RPE produces oxidants, free radicals and reactive oxygen species (ROS) – well managed in youth – but accumulation of these leads to disease in the aged eye.

There is a need to find an effective prevention and/or treatment for ARMD before it evolves to advanced disease. In the normal retina, the RPE performs multiple functions in the retina. During aging and in the presence of disease the robustness of each of these functions diminishes.

Studies of the the RPE indicate that the capacity of the RPE to replace itself in response to injury is compromised with aging.