What are Drusen?
Drusen are tiny yellow or white deposits or accumulations of extracellular material that develop in layer of the retina called Bruch’s membrane which is located just underneath the pigment epithelium in front of the choriocapillaris. The occurrence of small hard exudates is very common as a person ages. The development of larger soft drusen is a common early sign of the beginning of age-related macular degeneration. Drusen are made up of lipids or fatty proteins.
Small Hard Drusen
Small hard drusen have sharp margins and have a round shape. They are usually scattered and are most likely not an indicator of a person developing age-related macular degeneration.
Large Soft Drusen
Large soft drusen have soft or fluffy borders and are closer together. Because of their size drusen can disrupt the layers of the retina and can cause a retinal pigment epithelial detachment. These large soft drusen indicate an increased risk of developing age-related macular degeneration.
Types of Age-Related Macular Degeneration (AMD)
Dry Macular Degeneration
Dry macular degeneration is the most common type of age-related macular degeneration. Dry macular degeneration comprises ninety percent of cases. It is characterized by cells slowly degenerating over time. This gradually causes loss of central vision that we use for reading, driving, and all our clear vision. There are three stages of dry age-related macular degeneration.
The retina may have a few small drusen and very mild retinal pigment epithelial mottling. The patient will usually not have any vision symptoms related to the macular degeneration at this stage.
The retina may have a few medium sized drusen or a couple large soft drusen. There will be more retinal pigment epithelial mottling. The patient may notice changes in their vision at this level of macular degeneration.
The retinal may contain many large soft drusen and will have significant retinal pigment epithelial loss and may be called geographic dry age-related macular degeneration. At this stage the patient will have significant loss of central vision.
Wet Age-Related Macular Degeneration
This type of macular degeneration totals ten to fifteen percent of cases. Wet age-related macular degeneration is characterized by abnormal vessels underneath the retina growing under the macula and bleeding or leaking fluid into the macula. This is treated by intraocular injections of anti-VEGF injections to shrinks these abnormal blood vessels.
Diagnosis of Age-Related Macular Degeneration
The diagnosis of age-related macular degeneration is done by having an eye doctor examine the retina and observing the changes in the macula. Fluorescein angiography and OCT are common used to diagnose the extent of the macular degeneration.
If you have macular degeneration, drusen, or family history of age-related macular degeneration be sure to see your eye doctor and follow their recommendations in order to give you the best chance of maintaining your vision.