By REBECCA WALSH health reporter

People who quit smoking, even late in life, can reduce the risk of developing an age-related eye disease, research suggests.

Australian eye specialist Professor Paul Mitchell said people who smoked were three to four times more likely to develop macular degeneration than those who did not.

They also tended to develop it 10 years earlier than non-smokers.

But research indicated that it was difficult to demonstrate the same risk in people who gave up smoking.

Professor Mitchell, who was in New Zealand as part of the Save our Sight awareness campaign, said GPs often struggled to find reasons to tell elderly patients why they should give up smoking.

"The attitude of people in their 60s and 70s is, 'what good would it do me now to stop smoking?'

"We want doctors to know the evidence suggests strongly that stopping smoking even late in life may reduce a person's risk."

Professor Mitchell, head of ophthalmology at Sydney University, said there were two theories why smoking had such an impact.

One was that it caused constriction of the blood vessels. The other, more likely, explanation was that smoking depleted what was thought to be a protective pigment layer on the macula.

High-fat diets also put people at risk, and a diet rich in fish was known to be beneficial.

An American study which followed 4000 people with the early signs of macular degeneration found those who supplemented their diet with antioxidants and zinc had a 25 per cent reduction in the development of late-stage macular degeneration.

People who had a family history of the disease were at greater risk.

Dr Lesley Frederikson, national director of the Association of Optometrists, said the association would talk to the Ministry of Health about setting up a targeted screening programme for those at risk of the disease.

Early detection could slow the progression of the disease and allow people to maintain their independence for longer, creating significant long-term savings.

Studies had shown that people with macular degeneration were more likely to have falls and longer hospital stays and to be admitted earlier to rest-homes.

How our eyesight fails

The macula: The centre of the retina, responsible for detailed central vision and most colour vision.

Macular degeneration: A degenerative eye disease that causes progressive loss of central vision, Usually related to ageing, mostly affects people over 50 years of age.

Early symptoms: Distortion in seeing straight lines, a dark grey patch in the central field of the eye, sudden changes in vision.

Prevalence: In New Zealand an estimated 25,000 people have macular degeneration and 7000 are blind from it. A further 50,000 are thought to have the early stages of the disease.

Treatment: Laser treatment or photo dynamic therapy, involving a light-activated drug which targets and seals leaky blood vessels.

Herald Feature: Health

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