AGE-RELATED MACULAR DEGENERATION

Age-related macular degeneration (AMD) is a degeneration of the retina and choroidea (choroid) that results in a significant decrease in visual acuity.

In developed countries, AMD is the leading cause of significant vision loss in people over 50.

Early AMD may be asymptomatic. But as the disease progresses, the following symptoms may appear:

• curvature of straight lines,
• reduced intensity and brightness of colours.

At an advanced stage:

• central vision is significantly reduced,
• a dark spot appears in the center.

Causes

The exact cause of AMD is unknown, but the conditions for its development are changes that accompany age.

There are two main types of AMD:

• dry form,
• wet form.

The early stage of the dry form of AMD is manifested by the appearance of light yellow druses that form under the retina. Drusen are usually harmless, but when they merge, dry AMD can progress and lead to atrophic changes.

The atrophic area of the retina can also spread. If it is extensive and has clear margins, then it is called geographic atrophy (GA).

GA is the main type of dry AMD, which is often associated with loss of central vision.

What happens with a wet form of AMD:

• a sudden or gradual decrease in visual acuity,
• the appearance of a dark spot in the center,
• curvature of straight lines.

Choroidal neovascularization (CNV) is a hallmark of wet AMD.

CNV is formed when pathological vessels grow under the retina. They can bleed or leak, leading to deformation of the retinal structure.

Ultimately, CNV can develop into a disc-shaped scar that replaces the normal tissue of the outer retina and leads to a permanent decrease in central vision.

Risk factors for AMD

• Age (main risk factor)
• Work with a lot of mental stress
• Light iris colour
• Hyperopia
• Diseases of the cardiovascular system
• Family history
• Smoking
• High blood pressure
• High cholesterol
• Long sun exposure
• Low consumption of fish in the diet

AMD is more likely to develop in women than in men, and predominantly in Caucasians.

Diagnostics

Diagnosis of AMD patients begins with an examination of the fundus behind a slit lamp. Additional diagnostic methods are used to confirm the diagnosis:

• Optical coherence tomography
• Fluorescein angiography (FAG)
• Indocyanine green angiography (ICGA)

Treatment and prognosis

Following the discovery of vascular endothelial growth factor (VEGF) by scientists, progress has been made in the treatment of wet AMD in recent years. VEGF regulates the growth of pathological neoplasms of the eye, known as neovascularization, which can lead to wet AMD.

Anti-VEGF drugs have been discovered to block neovascularization and preserve vision in AMD patients. Two anti-VEGF drugs are officially registered in Russia:

• Lucentis
• Eylea

The wet form of AMD cannot be completely cured, but its progression can be stopped — with the help of intravitreal injections of anti-VEGF drugs.

There are three anti-VEGF treatment regimens for wet AMD:

1. “Treat and Observe”: the patient receives three monthly injections in a row, and then is under dynamic observation, and in case of deterioration of visual functions, receives the next injection of the drug.
2. “Treat and Extend”: after three monthly injections, the subsequent period between the introduction of drugs is gradually increased until the wet form of AMD is stabilized.
3. Monthly injections throughout the year.

Anti-VEGF therapy has significantly improved the treatment of wet AMD. Since 2005, patients with wet AMD are much more likely to maintain central vision, an ability for reading, driving; they recognize people’s faces and live normal lives.

The AREDS Association (Age-Related Eye Disease Studies), together with the National Eye Institute, have developed a dietary supplement formula that prevents the development of dry AMD.

AREDS supplement is widely available and contains a daily requirement of ingredients:

• lutein
• zeaxanthin
• vitamin C
• vitamin E
• zinc

Although patients with macular degeneration suffer from a pronounced deterioration in visual acuity, they cannot completely go blind — peripheral vision is preserved.

The disease can be detected using OCT (optical coherence tomography).

The Foundation launched the School of Health project, which aims to prevent eye diseases in humans. At regular free events of the project, doctors of various clinics talk about what diseases lead to visual impairment and how to prevent them.

Each listener receives a referral for free OCT examination of the posterior segment of the eye.