AMD 101: What Are Drusen?
Originally published by The Retina Eye Center
Did you know that "drusen," a German term for "rock" or "geode" due to their appearance, are tiny deposits in the eye with significant implications? Although typically managed by immune cells, drusen can accumulate, potentially leading to age-related macular degeneration (AMD), a leading cause of irreversible vision loss in individuals aged 50 and older in the United States. Understanding drusen underscores the importance of regular comprehensive ophthalmologic exams and indicated retinal exams.
These retinal waste materials, appearing as yellow or white deposits roughly the width of a pinhead, consist of natural molecules such as lipids and proteins. Drusen expansion or multiplication can result in growth beneath the retina, potentially signaling retinal problems or the onset of AMD. While the direct causation of AMD by drusen remains unclear, a larger drusen size or greater number can increase the risk of central vision loss by up to 50%.
Drusen and Dry AMD
Drusen are telltale early indicators of “dry” age-related macular degeneration. While dry AMD may have no symptoms, it can develop slowly and gradually, affecting central vision. Individuals with dry AMD may experience blank spots, blurriness, or difficulty adjusting to changes in light. Drusen proteins may disrupt immunity, specifically, the complement system, which regulates white blood cells and targets invaders such as bacteria. Having certain gene changes may increase dry AMD risk. Genetic predispositions can also heighten the risk of developing dry AMD.
Drusen and Geographic Atrophy
In advanced stages, excess or larger drusen can contribute to geographic atrophy, a severe and final manifestation of dry AMD. This condition poses a significant threat to vision as accumulated drusen beneath the retina damages the retinal pigment epithelium (RPE), a crucial tissue layer responsible for various retinal metabolic processes. As RPE cells deteriorate, central vision loss intensifies, resulting in symptoms such as dulled or washed-out colors, decreased visual acuity (sharpness and clarity), and irreversible vision impairment. Understanding the impact of drusen on geographic atrophy underscores the urgency of early detection and proactive management to preserve vision integrity.
Drusen: Risk Factors, Diagnosis, and Treatment
Certain factors, including ethnicity, smoking, obesity, poor diet, underlying health conditions, and prolonged UV exposure, increase the risk of developing drusen and AMD. Caucasians are more susceptible, and there may be higher risks for future central vision loss from geographic atrophy. Drusen may also coincide with neovascularization, often seen in wet AMD, characterized by abnormal blood vessel growth beneath the retina, leading to blood leakage.
Additional risk factors include:
- Family history
- Smoking
- Obesity
- Poor diet
- Underlying conditions such as high blood pressure or high cholesterol
- Light-colored irises
- Long-term, unprotected exposure to harmful ultraviolet (UV) rays
Drusen can develop asymptomatically and is typically detected during routine retinal diagnostic testing or through retinal photography after dilation. Ophthalmoscopes are commonly used devices to locate drusen, and patients may be provided with an Amsler grid to monitor AMD symptoms. While small drusen may require no immediate treatment beyond regular monitoring, larger ones may necessitate AMD treatments, such as anti-VEGF medications, to prevent neovascularization.
Preventive measures, such as those outlined in the groundbreaking Age-Related Eye Disease Studies (AREDS and AREDS2), which include a blend of nutrients, have shown significant reductions in vision loss risks. Generally, as drusen cases seldom progress to wet AMD, patients can anticipate leading normal lives with proper management.
Learn More About Drusen
Drusen, characterized as fatty, age-related deposits, serve as potential indicators of dry age-related macular degeneration (AMD) and its advanced stage, known as geographic atrophy. Regular and thorough ophthalmologic and retinal examinations facilitate the timely detection of drusen, enabling early intervention and treatment to preserve vision integrity. To prioritize your ocular health and address any concerns regarding your retina, we encourage you to schedule a retinal exam or consultation with us today.