Drusen are small, yellowish deposits that form beneath the retina, accumulating between the retinal pigment epithelium (RPE) and the underlying Bruch’s membrane. These deposits are primarily composed of lipids, proteins, and cellular waste products, representing a buildup of materials the eye’s metabolic processes fail to clear completely. While a few small drusen can be a normal sign of aging, a greater number or larger size of these deposits is considered a hallmark of Age-Related Macular Degeneration (AMD). The presence of extensive drusen indicates an increased risk of progression to advanced AMD, which is a leading cause of central vision loss.
Understanding the Possibility of Reversal
The primary goal of current medical management is preventing the progression from intermediate AMD to the late, vision-threatening stages, rather than the guaranteed elimination of drusen. There is no universally effective treatment to fully reverse or eliminate large, confluent drusen deposits once they have formed. However, small drusen can sometimes spontaneously regress or disappear without leading to vision loss.
The presence of numerous large drusen signals a dysfunction in the RPE layer, which is responsible for clearing metabolic waste. Intervention focuses on stabilizing the environment to halt the growth of existing drusen and prevent the formation of new ones. In some cases, drusen regression is observed, but this can sometimes precede the development of geographic atrophy, a form of advanced dry AMD.
Medical and Procedural Treatments
Certain procedures have been explored to encourage drusen to resorb, though these are not yet routine treatments. Laser photocoagulation and, more recently, subthreshold laser treatments have been shown to cause drusen to disappear temporarily. This mechanism involves a mild thermal effect that stimulates the retinal pigment epithelium (RPE) to become more active in clearing accumulated waste.
Initial studies on traditional laser photocoagulation failed to show a consistent reduction in the overall risk of progression to late-stage AMD. Subthreshold lasers, which use a non-damaging energy level, are still being investigated to see if they can achieve drusen regression without causing permanent damage to the overlying retina. These procedural options are generally reserved for specific, high-risk cases and are not a standard part of care.
Lifestyle and Nutritional Management
The most evidence-based strategy for managing drusen and slowing the progression of intermediate AMD involves specific nutritional supplementation and significant lifestyle modifications. The Age-Related Eye Disease Studies (AREDS and AREDS2) established that a high-dose combination of antioxidants and zinc can reduce the risk of advanced AMD progression by about 25% over a five-year period. The current standard is the AREDS2 formulation, which is recommended for people with extensive intermediate drusen or advanced AMD in one eye.
The AREDS2 formulation includes:
- Vitamin C (500 mg)
- Vitamin E (400 IU)
- Zinc (80 mg)
- Copper (2 mg)
- Lutein (10 mg)
- Zeaxanthin (2 mg)
Lutein and Zeaxanthin are carotenoids that accumulate in the macula, where they filter damaging blue light and provide antioxidant protection. The original AREDS formulation included beta-carotene, which was replaced in AREDS2 due to its link to an increased risk of lung cancer in smokers.
The single most impactful lifestyle change is the complete cessation of smoking, which is the greatest modifiable risk factor for AMD. A diet rich in leafy green vegetables, such as spinach and kale, provides natural sources of Lutein and Zeaxanthin. Consuming cold-water fish high in omega-3 fatty acids, like salmon and tuna, has also been associated with a lower risk of advanced AMD progression. Protecting the eyes from ultraviolet (UV) and high-energy visible blue light by wearing sunglasses outdoors may help reduce oxidative stress on the macula.