Drusen are associated with macular degeneration but are not diagnostic of the disease. Too many feel that these “spots” are indicative of ARMD, but they can, and often are, normal.
What Are These White Lesions?
Drusen are white spots, or lesions, seen within the layers of the retina. There are two types; hard and soft. The differences between the two are somewhat subtle.
Hard drusen are small and well defined with sharp borders. A poppy or sesame seed is an example of an object with sharp margins. “Hard” can be associated with macular degeneration, usually dry.
Soft drusen are larger and have fluffier borders. A cotton ball has fluffy margins. “Soft” can be normal, but are usually seen more often with exudative, or wet, ARMD.
Drusen, by definition, can be found anywhere in the retina. When they are located outside the macula, they are usually of no consequence and not related to any disease, especially macular degeneration. I am usually concerned when they are located within the macula.
But most non-retina people (i.e. doctors) are afraid to mention this – drusen away from the macula are of little consequence and can just be a family trait – if anything.
Other “Findings” of Macular Degeneration
“Findings” are the signs or physical characteristics of disease. These are things we look for as signs of disease.
Symptoms of ARMD are ways you describe changes in your vision.
Other signs of ARMD include, atrophy of pigment, increased pigmentation, fluid and blood. There may be fibrosis – a sign of old choroidal neovascularization.
Many doctors will term anything abnormal in the macula as “scars.”
Making the Diagnosis of Macular Degeneration
Patients have to have 3 criteria;
- Patients have to be over 50-55 years old
- Patients have to “look” like they have the disease (that is, they have signs)
- Patients have to have “symptoms” of the disease (that is, they have decreased vision)
Having just drusen, for example, but no change in vision or other signs of the disease, probably do NOT signify macular degeneration. It may be a sign of early disease and careful monitoring may be prudent.
Many times macular degeneration is diagnosed based solely upon the physical findings, but unless there is any evidence of decreased vision, I’d hold off on making the diagnosis.
Best Test for Diagnosis
If there is any doubt about the diagnosis of macular degeneration, the single best test, in my opinion, is a fluorescein angiogram. This test can show any damage to the macula that can not be seen by the usual methods. More subtle damage can be detected in this manner.
Drusen, unassociated ARMD, will not show any macular damage.
What Does This Mean? This means there are far fewer patients that actually have the disease than are diagnosed. In other words, there are instances where ARMD shouldn’t really be diagnosed. Many docs feel that it is safer to give the diagnosis for liability reasons.
I don’t understand this.
If there is any question about the presence, or absence, of macular degeneration, have your doctor order a fluorescein angiogram.