What to know about age-related macular degeneration

Age-related macular degeneration (AMD) is a common eye disease that typically affects people over the age of 50. It causes sight loss when looking straight ahead, due to dysfunction with the macula. In this article, a consultant ophthalmologist explains what causes macular degeneration and the variety of treatment options.

What is age-related macular degeneration?

The macula lies in the centre of the retina, which is the photosensitive layer of tissue that lines the back of the eyeball. The retina focuses the light that passes through the eye and transmits it as electrical signals to the brain along the optic nerve, where they are then converted into images. The macula’s role in this is to be in charge of the central vision, fine details, and a large part of colour processing.

So, when the macular becomes damaged or starts breaking down, a patient may be unable to see what is directly in front of them clearly, but their peripheral vision will remain intact. It can develop in both eyes at the same time (and they may not be equally affected), or it can occur in only one eye.

There are two types of AMD:

• Dry AMD, caused by buildups of protein called drusen that form underneath the macula and dry it out. This gradually causes the macula to be brittle, forming patches of missing vision that get bigger over time. Dry AMD is the most common type.
• Wet AMD, caused by blood vessel dysfunction where they begin leaking blood and fluids underneath the retina and macula. This causes scars to form, leading to distortion, blurring, and black patches in the central vision. Wet AMD is more urgent and requires immediate care in order to avoid complete loss of central vision.

AMD is, of course, related to ageing – however, related risk factors include smoking tobacco, obesity, genetic family history, and gender (women develop AMD more than men).

What are the symptoms of age-related macular degeneration?

The symptoms of AMD can include:

• Blurry vision
• Difficulty seeing in low light
• Difficulty perceiving colours
• Black or blank spots across the central vision
• Straight lines appearing as curvy or wavy
• Changes in height and depth perception
• Difficulty processing fine details

How is age-related macular degeneration diagnosed?

In the beginning, macular degeneration may not be noticed by a patient due to a lack of symptoms, thus it is primarily diagnosed in later stages or during an eye check-up.

If a patient is suspected of having AMD, then further testing to confirm the diagnosis will be conducted, such as visual acuity tests, dilated eye exams, optical coherence tomography, where 3D images are taken of the back of the eye where the macula is located, and fluorescein angiography, where a coloured dye is injected into the arm and the blood flow in the eye is monitored for leakage that indicates wet AMD.

How is age-related macular degeneration?

Macular degeneration is uncurable, so treatment aims to slow down its progression and improve the vision where feasible, ideally over the years. That is why an early diagnosis is preferable to start treatment and management to salvage as much of the vision as possible.

Progression may be slowed with AREDS and AREDS2 vitamins, which are high in vitamins and zinc, particularly for dry AMD. Other methods include Photobiomodulation, a kind of light therapy that stimulates cells in the retina called the retinal pigment epithelium to reduce the amount of drusen behind the macula and may slow down the degeneration.

Wet AMD can be managed with injections of anti-vascular endothelial growth factor (anti-VEGF) into the eye, as it stops new blood vessel growth and prevents further leakage. Injections are administered roughly every two months.

If you are having vision problems, you can consult with a specialist on Top Doctors.