New treatments a sight for sore eyes

By KATHERINE HOBY

More New Zealanders than ever are facing the threat of blindness.

Some could have had their sight saved by new treatments, but did not have their eyes checked in time.

Age-related macular degeneration (AMD), diabetes and glaucoma are robbing people of sight in "epidemic proportions", the Association of Optometrists notes.

Dr Lesley Frederikson, the association's national director, is urging New Zealanders to go for eye checks regularly.

She says conditions that once unavoidably led to blindness can now be treated. But they must be detected and dealt with before the damage caused is irreversible.

"Diseases which can lead to blindness such as age-related macular degeneration, diabetic retinopathy and glaucoma can be easily detected by your optometrist.

"And if found early enough, they can be treated and sight saved."

Optometrists sometimes detect life-threatening problems in the course of eye checks.

Dr Frederikson says it is vital the message gets through that early detection is the best protection against losing sight.

"Treatments can only stop the loss of vision.

"They cannot restore sight that has already been lost.

"That's why it is so important people have their eyes examined regularly."

At least 20 per cent of blind New Zealanders could have had their sight saved had their eyes been checked early enough.

The optometrists association, the Royal Foundation for the Blind, Retina New Zealand, Diabetes New Zealand and the Save Sight Society are running a campaign this month to encourage New Zealanders to protect their sight.

The Save Our Sight campaign encourages regular eye checks and other checks that can detect the onset of diseases such as AMD and diabetes which can lead to blindness.

Dr Frederikson says the number of people facing the threat of blindness from age-related eye diseases is expected to double in the next 30 years as the Baby Boomer generation aged.

"Diabetic retinopathy is a leading cause of blindness in the industrialised world.

"We have around 150,000 New Zealanders diagnosed with diabetes and probably that number again who remain undiagnosed.

"Glaucoma is affecting around one in 10 New Zealanders, with older people more likely to be at risk. And now AMD is a leading cause of blindness among older people," says Dr Frederikson.

An estimated 20,000 New Zealanders have late-stage AMD and a further 2000 develop it each year.

But Dr Frederikson says loss of sight from most eye diseases and disorders could be reduced with early detection and treatment.

"Even AMD, which was previously little-discussed because not much could be done about it, can now be treated."

AMD is a retinal degenerative disease which causes a progressive loss of central vision.

The macula is the central portion of the retina, responsible for perceiving fine, visual detail.

Light-sensing cells in the macula, known as photoreceptors, convert light into electrical impulses which they send to the brain.

Central vision loss occurs from AMD when photoreceptive cells in the macula degenerate.

New Zealand has just five retina specialists, among them Auckland-based Dr Dianne Sharp.

She says there are two types of AMD - dry and wet.

Nothing can be done about dry AMD, which leads to a gradual thinning of the retina, she says.

"But with wet AMD - if it is picked up early enough - there is a photodynamic therapy using a drug called Visudyne which can stabilise vision loss in up to 90 per cent of AMD patients in three years.

"People with AMD may first notice a blurring of central vision that is most obvious when they're doing visually detailed tasks such as reading or sewing," Dr Sharp says.

"Blurred central vision may also make straight lines seem slightly distorted or warped."

A simple test, known as the Amsler Grid and consisting of parallel and perpendicular lines with a spot marked in the middle, can provide clues.

If the lines appear distorted or blurred when the patient focuses on the spot, it can be a sign of AMD.

Dr Frederikson says: "Blindness has an enormous impact on quality of life, and for many people, the most important preventive measure is to have regular eye examinations by an optometrist.

"For at least 20 per cent of the people registered with the Royal New Zealand Foundation for the Blind, their loss of sight was preventable. That's a tragedy."

Treatments are available for most causes of sight loss, including diabetic retinopathy and glaucoma.

But early detection is critical, she says, to stop deterioration.

Regular eye examinations can sometimes reveal conditions that threaten more than sight.

Many optometrists have saved lives by finding underlying brain tumours, or haemorrhages, early.

Aucklander David Hayes is grateful to his optometrist for detecting a tumour at the base of his brain.

His only symptom was blurry vision, and he did not even have a headache.

Because his tumour was found early it was easily removed, and he was back at work within five weeks.

In the case of Eila Byrne, a visit to an optometrist detected AMD.

Treatment stopped further degeneration, preventing blindness from robbing her of the important activities in her life.

Around 81,500 New Zealand adults and 13,200 children are blind or have a sight impairment that cannot be corrected by glasses or contact lenses.

Retina New Zealand president Anthony Haas, himself an AMD sufferer, says he is committed to educating New Zealanders about annual eye checks.

Even those who have one condition should be vigilant about the symptoms of other diseases.

Eyecare needs to start when young, says Mr Haas.

He would like to see a national eyecare system put in place.

"As a consumer, I have been dissatisfied with a number of points from diagnosis to support - and I would definitely like to see some changes."

Defining the eye diseases

Age-related Macular Degeneration or AMD is a retinal degenerative disease that causes a progressive loss of central vision. Likening the eye to a camera, the retina is the film, while the macula is the central portion of the retina responsible for perceiving fine, visual detail.

Light-sensing cells in the macula, known as photoreceptors, convert light into electrical impulses and then transfer these impulses to the brain, by the optic nerve.

AMD causes central vision loss when the photoreceptive cells in the macula degenerate.

Glaucoma results from damage to the optic nerve at the back of the eye. It can cause visual field loss and, if uncontrolled, may lead to blindness.

Several factors increase your risk of developing glaucoma - family history, increasing age and associated conditions such as diabetes and high blood pressure.

Diabetic retinopathy is an abnormality of blood vessels which supply the retina, the layer lining the inside of the eye and which acts like a film in a camera.

These blood vessels leak fluid, causing a loss of reading vision, or abnormal blood vessels develop and can haemorrhage, leading to a more severe loss of vision.

All people with diabetes are at risk of developing this condition and after 10 years with diabetes all people will have some degree of retinopathy.

* To contact a Retina NZ peer supporter in your area, phone 0800 243 333 or for more information, visit Retina NZ

* The Royal New Zealand Foundation for the Blind

phone 0800 243 333

* Diabetes New Zealand

phone 0800 342 238

Further reading
nzherald.co.nz/health