Macula Degeneration

What is Macular Degeneration?

Age-related macular degeneration damages the part of the eye responsible for central vision. It tends to affect people later in life — usually those over 65, although symptoms can appear in the 50s or early 60s. It does not necessarily cause total blindness, but it can affect both near and distance vision and, left untreated, can seriously interfere with daily activities such as reading and recognising faces. There are two types of macular degeneration: dry and wet.

Around 90% of all those affected have the dry form. In dry age-related macular degeneration — sometimes called non-neovascular AMD or non-exudative AMD — the macula (part of the retina) becomes progressively thinner, causing visual changes that include blurring, reduced central vision, less intense colour perception and difficulty seeing in low light.

Before treatment for macular degeneration

Your vision is blurred, with shadowy spots towards the centre.

After treatment for macular degeneration

The shadowy spots are gone and vision is improved.

How do I know if I need to find a doctor who specialises in macular degeneration?

With natural ageing, almost everyone over 50 will have some slight deterioration in the macula. Dry macular degeneration causes a lesion of the retina in which small deposits, called drusen, form beneath the macula; most people aged 50 and over will have at least one small drusen. Very often the condition never progresses beyond this stage, and there will be few or no symptoms.

This is one reason why everyone over 50 may need the services of a medical retina specialist: in the early stages there may be very few noticeable signs, or none at all.

The condition affects central vision (not peripheral) and can occur in one or both eyes. Some of the early signs include:

• A blurred or distorted area in the centre of your vision
• Colours appearing less bright
• Straight lines appearing wavy or crooked
• Objects looking smaller than normal
• Hallucinations

If the early stages are detected during a routine eye examination, it is vital that the condition is monitored regularly. An ophthalmologist can use a number of tests to check for any progression, such as:

• Vision tests: These involve looking at a grid of straight lines (called the Amsler grid). If any lines are missing or appear wavy, this may be a sign of macular degeneration.
• Angiography or OCT: A dye is injected into the body’s vascular system, and the medical retina specialist follows its passage through the blood vessels of the eye.

What happens during the treatment of macular degeneration?

Treatment for age-related macular degeneration depends on the type you have. Dry AMD is usually managed with visual aids, dietary choices and vitamin supplements.

Wet AMD can be treated with eye injections or with photodynamic therapy/laser therapy.

• Eye injections: Your eye is numbed before treatment so that you feel nothing, or only minimal discomfort. Injections are given directly into the eye every one or two months (or for as long as necessary). The success rate is high: further deterioration is prevented in 9 out of 10 people, and 3 out of 10 find that their vision improves.
• Photodynamic therapy/laser treatment: This is used to seal or destroy the blood vessels that have formed behind the retina. It is sometimes used in combination with eye injections and is repeated every few months. There are two types of laser treatment — hot laser and cold laser. Hot laser treatment seals the abnormal vessels and discourages further growth; cold laser is used where there is an opportunity to destroy the vessels.

• Hot laser treatment can leave a tiny blind spot in your vision, as it can affect the surrounding tissue as well as the abnormal vessels. If this happens, however, most people adapt well and learn to ignore it.

Cold laser treatment is used for vessels that have formed in or near the centre of the macula.

Both procedures are performed under local anaesthesia, with drops and/or injections used to numb the eye. The laser then targets the blood vessels to treat, seal and/or destroy them. With cold laser treatment, a light-activated drug is injected into your arm, and the laser is applied as the drug passes through your cardiovascular system and reaches the eye.

It is common to have temporary vision problems after the procedure, and you should avoid bright sunlight. Your medical retina specialist will advise you on exactly how long recovery will take and how to look after yourself before returning to normal activities.