Drusen are small, yellowish deposits that form under the retina, the light-sensitive tissue at the back of the eye. While common with aging, their presence can indicate an increased risk for age-related macular degeneration (AMD). Understanding drusen is important for maintaining long-term eye health.
What Are Drusen?
Drusen are tiny accumulations of extracellular material, primarily fats, proteins, and cellular waste products. These yellowish deposits form between the retinal pigment epithelium (RPE) and Bruch’s membrane, layers located beneath the retina. When found in the macula, the central part of the retina responsible for sharp, detailed vision, they are referred to as macular drusen.
Drusen are categorized into two main types. “Hard drusen” are small, round, with well-defined borders, and are a common, usually harmless part of aging, especially in individuals over 50. In contrast, “soft drusen” are larger, pale yellow or grayish-white, with indistinct borders, often clustering together. The presence of soft drusen is more significant, as they are frequently associated with eye health concerns.
Drusen and Age-Related Macular Degeneration
The presence of drusen, particularly soft drusen, indicates an increased risk for age-related macular degeneration (AMD). AMD is a leading cause of central vision loss in older adults, affecting tasks like reading and recognizing faces. While drusen alone do not guarantee AMD development, their size and number can significantly increase the risk of progression.
Drusen contribute to AMD by potentially impairing the retinal pigment epithelium, which is essential for photoreceptor cell survival. This can lead to a gradual breakdown of the macula. AMD primarily presents in two forms: dry AMD and wet AMD. Dry AMD is the more common type (80-90% of cases), characterized by drusen accumulation and macular thinning.
Wet AMD, though less common, is more severe and can lead to rapid vision loss. This form involves the growth of abnormal blood vessels under the retina, which can leak fluid or blood, damaging the macula. Soft drusen can precede wet AMD, suggesting metabolic changes within these deposits may promote abnormal blood vessel growth. Symptoms of AMD progression include hazy or distorted central vision, blank spots, or wavy straight lines.
Identifying and Monitoring Drusen
Drusen are typically discovered during a comprehensive dilated eye examination. Many individuals with drusen do not experience noticeable symptoms, making routine eye exams important for early detection. During the exam, an ophthalmoscope views the back of the eye to identify deposits. Optical Coherence Tomography (OCT) provides detailed cross-sectional images of the retina, allowing for precise visualization and measurement of drusen.
Regular monitoring is advised for individuals diagnosed with drusen, especially soft or numerous ones, to track changes and detect AMD progression. Eye care professionals may recommend using an Amsler grid at home to self-monitor for central vision changes, such as wavy lines or blank spots, which can be early signs of AMD. While no specific treatment eliminates drusen, lifestyle adjustments can support eye health and potentially reduce AMD progression risk.
Not smoking is important, as it is a known AMD risk factor. A diet rich in leafy green vegetables, fatty fish, and antioxidants can also be beneficial. Maintaining healthy blood pressure and weight are additional measures that contribute to eye health. For some individuals with intermediate AMD, specific nutritional supplements (AREDS2 formula), containing vitamins C and E, lutein, zeaxanthin, zinc, and copper, may be recommended to slow disease progression.