30 Aug How to Diagnose Macular Degeneration
Unlike the diagnosis of diabetic retinopathy, a patient with macular degeneration must have symptoms of the disease for the diagnosis to be made. In most cases, the retina should have characteristic “damage,” and, most importantly, the patient must be having symptoms, i.e. decreased vision and/or distortion.
In Whom We Make the Diagnosis
Patients afflicted with macular degeneration are almost always greater than 55 years old, show signs of the disease, often of northern European ancestry and have decreased vision and/or distortion.
The disease is progressive and, in most cases, affects both eyes.
Symptoms of Macular Degeneration
As I wrote last week, a patient with diabetic retinopathy may not have anything wrong with their vision, that is, they may not have symptoms.
A patient with macular degeneration must have visual symptoms.
What are Drusen?
Some of the hallmarks of macular degeneration include the presence or absence of pigmentary changes, fluid, blood and drusen.
Drusen are creamy white spots within the layers of the retina. There are two types, hard and soft, but both can be associated with macular degeneration. They are not diagnostic of the disease, but many non-retina physicians know this.
Drusen may be present in the retina without other evidence of degeneration. Drusen may be normal.
Fluorescein Angiography is Diagnostic
As with any retinal disease, a good dilated pupil exam is necessary to look at the retina. If there are no signs of the disease, the vision is good, no further testing is needed.
If there are signs of the disease, then a fluorescein angiogram should be performed. This test involves injection of a dye into your arm. The dye travels to the retina and pictures are taken. A fluorescein angiogram is a great test for showing just how healthy, or unhealthy, the retina can be.
A fluorescein angiogram can diagnose macular degeneration.
What Does This Mean? In contrast to diabetes, where patients must be examined routinely due to the potential of a lack of symptoms, macular degeneration patients don’t benefit from routine examination if they have no symptoms. (I am not saying don’t get an eye exam as many people are unaware of having vision loss!)
By definition, macular degeneration damages the macula. Therefore, if present, there should be changes in the vision.
In cases of suspected macular degeneration, diagnostic tests are available. At times, patients can look like they have ARMD, yet have normal vision. As this is a progressive disease, those that are suspected of developing the disease should be followed regularly in years to come.
A normal fluorescein angiogram can also determine if drusen are normal, or associated with the disease.
As always, see your eye doctor if you develop any persistent decreased vision or distortion (symptoms continuously present for more than one day).