By the way, doctor: What are drusen, and why do I have them?
Q. My ophthalmologist says I have drusen scattered over the macula in both eyes and wants to check them every nine months. Could you say something about what drusen are and what they mean?
A. Drusen are small, yellowish deposits of cellular debris that accumulate under the retina — the light-sensitive layer of cells at the back of the eye that's essential to vision. Drusen occur in most people over age 60 and are more common in women than men.
How drusen form
Drusen are deposits of extracellular waste that accumulate under the retina, between a specialized layer of cells called the retinal pigment epithelium (RPE) and Bruch's membrane, a meshwork of fibrous proteins (mostly collagen). The RPE helps maintain the photoreceptors (the light-sensing cells that make up the bulk of the retina), transporting nutrients and wastes between the photoreceptors and the blood vessels that supply them. By age 60, changes take place that can cause drusen to build up on Bruch's membrane, which displaces the RPE and forces the two layers apart. Such disruption to the RPE can damage the photoreceptors. An increase in the number or size of the drusen increases the risk of age-related macular degeneration.