Drusen severity depends on if they're hard or soft
Dear Doctor: My eye doctor says I have something called “drusen” on top of my retina. I’ve read that this is connected to macular degeneration, and I’m worried. Can you please explain more about it?
Dear Reader: The term “drusen” is the plural of the German word “druse,” which means node. In a medical context, drusen refers to small deposits of debris within the retina. That’s the layer of tissue that lines the back of the eye and contains light-sensing cells known as photoreceptors. Drusen are found not on top of the retina, as you mention in your question, but in an area known as Bruch’s membrane. It’s a very thin layer of cells that separates the upper layers of the retina, including the photoreceptors, from an area known as the choroid. This is a network of blood vessels that deliver oxygen and nutrients to the macula, the functional center of the retina.
In order to diagnose the presence of drusen, your eye doctor performs a dilated eye exam. It involves the use of special eye drops that prevent the iris, which is the part of the eye that controls the size of the pupil, from contracting. With the iris wide open, the doctor can then use either a special instrument to see into the back of the eye or a special camera to photograph the interior structures. Drusen will appear as yellowish-white spots within the retina.
Drusen are described as either hard or soft. Hard drusen are small and round, have well-defined borders and are often spread out. They are common as people age. Soft drusen are larger, have indistinct borders and tend to cluster together. Although both types of drusen should be monitored, hard drusen don’t usually cause vision problems. Soft drusen, which can cause damage to the macula, are associated with dry age-related macular degeneration. That’s a condition in which the macula deteriorates and the center of the field of vision is compromised or even lost. Drusen can also be present on the optic nerve, which can result in a slight loss of peripheral vision. This is more common in children than adults.
There is no treatment available for drusen at this time. However, someone diagnosed with soft drusen may be asked to take a specialized combination of vitamins and minerals that have shown promise in slowing a certain type of age-related macular degeneration. Using data drawn from a large study known as AREDS 2 (Age-Related Eye Disease Study 2), researchers developed a nutritional supplement that has been shown to reduce one’s risk of developing advanced age-related macular degeneration by about 25%. The formulation includes vitamins C and E, copper, zinc and a pair of plant pigments called lutein and zeaxanthin, all in specific proportions.
Since you’re worried, it’s important to speak with your doctor and have all of your questions and concerns addressed. Be sure to ask if the drusen found in your eyes are hard or soft, as each type signals a different level of risk. And be vigilant about all follow-up visits to monitor your progress.
(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)