What is the difference between dry and wet age-related macular degeneration?

Understanding Age-Related Macular Degeneration (AMD)

Age-related macular degeneration (AMD) is an eye disease that can cause blurred central vision. It occurs when the part of the eye that controls sharp, direct vision—the macula—is damaged due to aging. The macula is a part of the retina, which is the light-sensitive tissue at the back of the eye [1]. Macular degeneration is a common condition and a leading cause of vision loss in older adults, but it does not lead to total blindness. However, the loss of central vision can make it difficult to see faces, read, drive, or perform detailed tasks such as cooking [1]. Macular degeneration develops very slowly in some people and more rapidly in others [1].

Major Types: Dry and Wet Macular Degeneration

There are two main types of age-related macular degeneration: dry and wet. Dry macular degeneration, also known as atrophic macular degeneration, is the most common form, affecting about 80% of those with the disease [2]. This type occurs when the macula thins with age, and small deposits called "drusen" may accumulate [1], [2]. Dry macular degeneration typically develops slowly over several years [1]. Wet macular degeneration, also known as advanced neovascular macular degeneration, is less common but more severe, and it typically causes faster vision loss [1], [2]. Wet macular degeneration occurs when abnormal blood vessels grow under the retina; these may leak fluid or blood, leading to scarring and damage of the macula [2].

Any stage of dry macular degeneration can progress to wet macular degeneration [1], [2]. Therefore, it is very important to monitor any changes in vision and report them to an ophthalmologist immediately.

Symptoms and Differences in Progression

Symptoms of macular degeneration vary depending on the type and stage. In the early stages of dry macular degeneration, there may be no symptoms at all [1]. In the intermediate stage, some people may still have no symptoms, while others may notice mild blurriness in their central vision or difficulty seeing in low light [1]. In the late stages of macular degeneration (whether dry or wet), many people notice that straight lines begin to appear wavy or distorted. They may also notice a blurry area near the center of their vision, which may expand over time or appear as empty spots. Colors may seem less bright, and vision in low light may become increasingly difficult [1].

An important warning sign of late-stage macular degeneration is the appearance of straight lines as wavy [1]. If you notice this symptom, you should visit an ophthalmologist immediately [1].

Available Treatment Options

Treatment for macular degeneration depends on its type and stage. Currently, there is no cure for dry macular degeneration in its early stages, but an ophthalmologist can monitor the condition of the eyes through regular exams [1]. For people with intermediate dry macular degeneration in one or both eyes, specific nutritional supplements (vitamins and minerals) may help slow its progression to late-stage macular degeneration [1], [3]. Studies such as AREDS and AREDS2 have shown that a specific formula of vitamins and minerals may slow the progression of dry macular degeneration in some people who have certain drusen or significant vision loss [2]. These supplements include Vitamin C (500 mg), Vitamin E (400 IU), lutein (10 mg), zeaxanthin (2 mg), zinc (80 mg), and copper (2 mg) [2]. You should consult an ophthalmologist to determine if these supplements are appropriate for your condition, as not all forms of dry macular degeneration benefit from them [2].

For wet macular degeneration, treatment options are available that can help stop further vision loss. These treatments include medications called anti-vascular endothelial growth factor (anti-VEGF) agents that are injected into the eye [1], [2]. These drugs help reduce the leaking from abnormal blood vessels and slow their growth [2]. Photodynamic therapy (PDT), a combination of injections and laser therapy, can also be used in some cases [1], [2].

Practical Steps to Protect Vision

In addition to medical treatments, there are practical steps you can take to protect your vision and manage macular degeneration. Quitting smoking, engaging in regular physical activity, maintaining healthy blood pressure and cholesterol levels, and eating a healthy diet including leafy greens and fish can help reduce the risk of developing macular degeneration or slow vision loss [1], [2]. Regular eye exams are crucial, especially for people over the age of 55 or those with a family history of the disease [1]. Since early macular degeneration causes no symptoms, do not wait until your vision changes to have your eyes checked [1].

To help monitor vision at home, many ophthalmologists recommend using an Amsler grid daily [2]. This grid helps detect changes such as wavy, missing, or distorted lines, which are early signs of macular changes [2]. If you notice any new distortions, you should contact your ophthalmologist immediately [2]. More information on protecting vision with age-related macular degeneration can be found on the Age-Related Macular Degeneration: Protecting Vision page (Arabic).

Medical references

• Age-Related Macular Degeneration (AMD)
• What Is Macular Degeneration?
• Age-Related Eye Disease Studies (AREDS/AREDS2)