Macular Degeneration

Below is information about the condition and how best to treat it. A PDF version is available at the bottom of the page.

What is it?

The retina is the light sensitive membrane attatched to the inner surface of the eye. Light enters the eye and falls on the retina allowing us to see images, these are transmitted along the optic nerve to the brain where they are processed so we can see.

The macula is a small area in the middle of the retina with the greatest amount of light sensitive cells and is used for fine-detailed central vision. Macular degeneration is a painless disorder that can affect either eye, causing progressive loss of central and detailed vision.

Age-related Macular Degeneration (AMD) is the most common form, although some forms affect younger people . There are two main types of AMD, referred to as 'wet' and 'dry'. This is not a description of how the eye feels, but of whether leaking blood vessels are involved. Dry AMD accounts for 90% of cases, with 10% being wet AMD. Dry AMD can become wet AMD.

What causes it?

Macular degeneration results from a partial breakdown of cells in the retina. Some layers of the retina thicken and waste material that is normally removed forms deposits, distorting the retina. The cause of the condition is unknown, however risk factors are considered to be:

  • Smoking
  • Family history of the disease
  • Exposure to ultraviolet light
  • Poor diet (which lacks antioxidant vitamins or are high in saturated fat)

What are the symptoms?

Wet AMD can cause a sudden onset of symptoms over days, resulting from build up of fluid under the retina. Dry AMD progresses slowly over a number of years and the symptoms will onset gradually and includes blurred or absent central vision. Distortion can also occur so that straight lines appear wavy, or objects appear larger or smaller than normal, making it difficult to read, recognise people, watch television and drive.

During your eye test the Optometrist may use an Amsler Grid, which is similar in appearance to the above. AMD patients often report that sections of the grid appear distorted or missing and that some of the boxes appear to be different sizes.

How is it treated?

'Wet' AMD– treatment is only effective if it is detected early; this is essential as it can damage vision rapidly. Laser surgery to stem leaking blood vessels may be used or repeated Photodynamic Therapy may be applied, where laser is shone on the eye activating a medicine that destroys abnormal vessels. Other treatment advances include injections of anti-VEGF drugs such as ‘Macugen’ directly into the eye.

'Dry' AMD – no treatment is available.

Evidence shows that increasing dietary antioxidants and carotenoids reduces the risk of AMD. Lutein and zeaxanthin are nutrients thought to help protect the macula; they are obtained from foods such as spinach, broccoli and sprouts which contain high levels. If you cannot increase your leafy green intake, supplements are available (e.g. I-caps).

For those with significant sight loss, magnifiers and high powered reading glasses can aid vision.

What can I expect to happen?

Your Optometrist will conduct tests if you have signs of AMD; this may include eye drops to dilate the pupil giving a better view of internal structures. You may then be referred to an Ophthalmologist who can diagnose AMD at an early stage using more complex tests. A fluorescein angiography may be done to check for abnormal blood vessels; this photographs vessels at the back of the eye with help from fluorescent dye that is injected into the bloodstream.

We recommend that you have an eye test every two years, unless your Optometrist advises otherwise.

If you have any queries please feel free to contact us.