Another study that says you are what you eat.

Researchers from Tufts University observed that a high glycemic index diet resulted in many AMD features including RPE hypopigmentation and atrophy, lipofuscin accumulation, and photoreceptor degeneration in mouse models. A low glycemic index diet did not show these changes. Of particular importance, they found that switching to a low glycemic index diet, even later in life stopped the progression of AMD. (via)
Here is a review on glycemic index.