What is the macula?

The retina lines the inside of the back two-thirds of the eye and acts like the film in a camera. At the very centre of the retina is the macula which is the part of the eye that we use for reading and performing other detailed visual tasks. This gives us central vision, as opposed to peripheral vision which is served by the rest of the retina allowing us to recognise our surroundings and movement of objects within this.

What is macular degeneration?

When the macula deteriorates, we call this degeneration and, while this may occur as an inherited condition, it more commonly develops in the ageing eye. Why this affects some older people and not others is not understood but it means that the patient may lose the ability to read and do other detailed functions.

Who gets macular degeneration?

Some are born with an inherited disease which, as they grow, causes a deterioration in the retina sometime in the early to late teens. This is a very uncommon condition and leads to a loss of reading vision. The most common form of macular degeneration is that which occurs in older people, which may cause a slow gradual deterioration in reading vision or a more sudden deterioration due to haemorrhage or leakage from blood vessels (disciform degeneration).

Preventing and treating macular degeneration

Lifestyle and diet are important for eye health in general and factors thought possibly to protect against macular degeneration, such as antioxidants lutein and zeaxanthin, vitamins C and E, zinc, selenium and omega-3 fatty acids, are still being studied. However, high blood pressure and smoking are known to increase the risk of visual loss from macular degeneration. Equally controlling high blood pressure and stopping smoking dramatically decreases that risk.

The National Eye Institute has also shown for patients with moderate or advanced forms of macular degeneration a combination of vitamins and antioxidants can be beneficial. In New Zealand, this formulation is not funded by Pharmac and before starting treatment it is advisable to have a thorough eye examination, including photographs of the macula, to ensure the medication is going to be of benefit.

Retinal laser surgery for patients with exudative complications of macular degeneration was the treatment of choice up until quite recently. However, the development of a class of drugs that can act on the abnormal leaking vessels in the eye has lead to a widespread change in practice. These drugs, such as Avastin and Lucentis, are injected into the vitreous cavity within the eye and allow for better visual outcomes compared with most forms of laser treatments. Regular retinal scans (OCT) are required to monitor the effect of the treatment and repeat injections are often required to reduce the leaking vessels causing the reduction in vision. 

Visual aids

Patients who lose or have defective reading vision can be helped with low visual aids such as magnifiers or closed circuit television. If the central vision is totally lost, talking books can replace the written word. More sophisticated aids with computers and talking typewriters can enable patients who lose central vision to continue to lead a normal life and occupation.

For further information and support talk to an optometrist or eye specialist. Optometrists are listed in the "Yellow Pages" of your telephone book. Eye specialists are listed with registered medical practitioners at the front of the white pages of your telephone book.

Original material provided by Auckland Eye, and updated May 2005. Edited by everybody.