Drusen

What Are Drusen?

Drusen (singular: druse) are yellow-colored spots that develop under the retina. For reference, the retina is the light-sensitive nerve tissue at the back of the eye that sends images to the brain for interpretation.¹ At the center of the retina is the macula, responsible for central vision (the ability to see objects clearly).

Drusen consist of protein and lipids (fat). Although not likely to affect the macula, drusen may increase the risk of dry age-related macular degeneration (AMD), a disease that affects a person's central vision.² 

According to one study, an increase of drusen over time indicates disease progression in AMD.³ Drusen are common among people over 60 years old. 

In rare cases, drusen can develop in the optic nerve. Optic nerve drusen can occur in children and adults and may affect peripheral vision (side vision).

An ophthalmologist can find and diagnose drusen during a dilated eye exam.⁴

What Causes Drusen?

Drusen results from the accumulation of proteins, lipids, and other unwanted material in the retina. Usually, the retinal cells dump waste material for the immune system (macrophages) to clean up. 

If there's excess waste disposal or impaired macrophage function, the "garbage" can pile up, appearing like yellow-colored spots under the retina.

A common protein in drusen is beta-amyloid. This protein is pro-inflammatory and common in the brain tissues of people with Alzheimer's disease.⁵ According to research, this shows a possible link between drusen and Alzheimer's disease.⁶

Types of Drusen

There are two types of drusen:⁷

1. Hard Drusen

Hard drusen appear as small and round or oval with distinct borders. They tend to spread out and may occur anywhere in the retina. They're unlikely to affect vision.

2. Soft Drusen

Soft drusen are larger than hard drusen and tend to cluster together. These are more serious and may cause bleeding or scarring of the macula.⁸ This will affect central vision.

Symptoms of Drusen 

Most people with drusen do not show symptoms. However, when the macula is affected, the following symptoms may develop:

• Straight lines appear wavy/curvy
• Blurred vision or haze
• Sensitivity, especially in bright lights
• Blank spots in your central visual field

What are the Risk Factors for Drusen?

Apart from age (65 years or older), other risk factors of drusen include:

• Gender (females are at a higher risk than males)
• Race (caucasians are at a higher risk)⁹
• Family history of AMD
• High cholesterol levels
• Presence of cardiovascular disease
• Smoking tobacco products

Can Drusen Lead to Blindness?

Drusen will not cause total blindness. However, if the macula is affected, you may lose your central vision. Without central vision, you lose the ability to see finer details of objects in front of you. This may occur if you have soft drusen.

Although hard drusen rarely causes eye problems, they may increase your risk of developing soft drusen, which are associated with AMD.

When to See a Doctor

Contact your doctor if you experience sudden vision changes or serious vision loss.

Diagnosis, Treatment, and Outlook

Your eye doctor can observe the presence of drusen during a dilated eye exam. First, they'll dilate (enlarge) your pupils by administering dilating eye drops.¹⁰ They'll then use a device known as an ophthalmoscope to observe the retina and surrounding areas.

If large drusen are confirmed, your ophthalmologist will check your eyes for any symptoms of macular degeneration, such as blurry vision and blank spots in your central vision. This will be done using an Amsler grid, a checkerboard-like pattern of straight lines. The lines may appear wavy or missing if you have intermediate to late-stage AMD.

Treatment

Drusen may disappear without treatment. However, this does not guarantee recovery from AMD.

If you have small drusen, you may not require treatment. Your eye doctor may recommend regular checkups to monitor progression. 

Large or soft drusen may signal dry or wet age-related macular degeneration (AMD). For this reason, your doctor will administer the appropriate AMD treatment.

There is no standard treatment for hard or soft drusen. However, some lifestyle changes might help slow down the progression. 

According to The Age-Related Eye Disease Study (AREDS) and AREDS 2 studies, certain vitamins and minerals may help reduce drusen accumulation.¹¹ These include:

• Vitamin C (500 mg)
• Zinc (80 mg)
• Lutein (10 mg)
• Copper (2 mg)
• Vitamin E (400 IU)
• Zeaxanthin (2 mg)
• Beta-carotene (15 mg)

Your eye doctor will tell you the best vitamins or minerals to take. Although beta carotene supports eye health and prevents eye diseases, it may increase the risk of lung cancer among smokers.¹²

To treat wet AMD, doctors use certain medications known as Anti-VEGF drugs, delivered into your eye using a very slender needle.¹³ They help reduce the number of abnormal blood vessels in the retina and reduce leaks.

Laser surgery such as subthreshold photocoagulation can be used to treat some types of wet AMD.¹⁴ In this case, your ophthalmologist will use laser light beams to reduce the number of abnormal blood vessels or prevent leakage into the retina that may cause drusen.

Prevention

You cannot prevent drusen development. However, early detection and continuous monitoring may help prevent macular degeneration. Early treatment of AMD can prevent disease progression or vision loss.

Outlook

AMD is the leading cause of vision loss in the United States and mostly affects people 60 years or older. Having a small number of drusen should not worry you as it's part of normal aging.¹⁵

But having a large number could signal age-related macular degeneration (AMD). Over time, macular degeneration may affect your central vision. Continuous monitoring of drusen can help your doctor manage your eye health.

Summary

Drusen are yellow-colored spots that form under the retina. They are caused by the accumulation of proteins, lipids, and other unwanted material in the retina.

Drusen can be soft or hard. The hard ones are small and round with distinct borders, whereas soft drusen are larger and tend to cluster together.

Although drusen are not likely to affect the macula, soft drusen may increase the risk of dry age-related macular degeneration (AMD).

When drusen affect the macula, straight lines might appear wavy. Blurry vision, blank spots in your central visual field, and sensitivity to light are also common. 

Although drusen may not lead to total blindness, you should contact your doctor if you experience any changes in vision, as this may worsen over time.

There is no treatment for drusen, although certain vitamins and minerals may help reduce drusen accumulation. Your doctor can also use Anti-VEGF drugs to prevent the development of abnormal or leaking blood vessels in the retina.

The best way to prevent drusen is through a healthy diet, early detection, and regular monitoring.