Eye Checks Can Avoid Blindness

SAVE OUR SIGHT August 2008

Eye Checks Can Avoid Blindness

Most people would agree losing their sight would be one of the most devastating disabilities to come to terms with.

And yet many people put off a simple action that could avoid blindness or at least minimise loss of vision due to a range of conditions easily diagnosed by an optometrist.

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

Throughout August the New Zealand Association of Optometrists (NZAO) has been focusing its annual Save Our Sight campaign on the problems associated with low vision.

Dr Lesley Frederikson, NZAO national director, says there are reasonably common conditions that an optometrist can diagnose, possibly treat or refer to an ophthalmologist to stop any further complications or loss of vision that the condition may have caused.

“But once sight has been lost, it’s generally gone forever.”

The key message is have a regular check up by an optometrist before vision deteriorates.

“Low vision is an ongoing and long term condition that has significant impact on a person’s life,” says Dr Frederikson.

“Reduced vision is an inevitable outcome of many chronic eye conditions including cataracts, glaucoma, macular degeneration and diabetes. The number of people affected by these conditions is increasing with our ageing population and one of the saddest facts is that if people were diagnosed with a condition early by their optometrist the degree of vision lost could be reduced.”

Age-related macular degeneration (ARMD) is one of the most common causes of low vision and visual impairment. Macular degeneration occurs when the centre part of the retina becomes damaged. This part of the retina is called the macula which is the part of the eye that helps people to see fine details.

“When it is damaged, the vision in the centre of your eye blurs or darkens. Jobs like reading, sewing or driving sooner or later can become very difficult and even impossible. There are two types of ARMD and are most commonly called the ‘dry’ and ‘wet’ types. About 90% of ARMD cases are the dry type,” Dr Frederikson says.

The first symptom is loss of ability to see objects clearly.

“Straight lines appear to be wavy or distorted. Other signs include a dark area blocking the vision in the centre of your eyes or grey and white spots appear in the centre of your vision. Sometimes there is a loss of clear and correct colour vision and print appears washed out when reading.

“Many people who are aged 70 and over have some macular degeneration. If there is a family history there may be an increased risk and in addition, people with certain medical conditions such as diabetes or other micro-vascular diseases may be more likely to develop macular degeneration. Again it’s important to make sure you have regular check ups with your optometrist or ophthalmologist.”

There are steps people can take to prevent ARMD, such as not smoking; eating fish and green leafy vegetables; taking dietary supplements and anti-oxidants and, especially if there is a family history, have a regular eye examination with their optometrist.

For many cases of ‘dry’ ARMD there is no treatment currently possible. Some cases of ‘wet’ ARMD are amenable for treatment by an ophthalmologist such as photodynamic therapy (PDT) or an injection of a particular drug, such as Lucentis or Avastin which is designed to block abnormal blood vessel growth and leakage.

“If your condition is not treatable or the treatment is not working, your optometrist may be able to help with special low vision aids to help with reading and close work tasks,” Dr Frederikson says.

Glaucoma is an eye condition that can result in too much pressure from eye fluid in the eye and another cause of low vision. This high pressure can damage the optic nerve and if the pressure persists, glaucoma will worsen your sight.

When left untreated, glaucoma can cause loss of sight in just a few years. Glaucoma NZ reports that 10 percent of people over 70 years will have glaucoma.

People at risk are:
• those over 40 years
• people with a family history of glaucoma
• short-sighted people
• those with diabetes or high blood pressure
• history of migraine
• people who use cortisone or steroids
• have a previous eye injury.

“Usually there are no symptoms except vision loss which is why it is so important people visit their optometrist for a regular check up – at least every two years.

“In a few cases, glaucoma will develop rapidly with blurred vision, loss of side vision, seeing coloured halos around lights, redness of the eye, nausea or vomiting and pain in the eye,” Dr Frederikson says.

While glaucoma can’t be prevented, it can be detected before vision loss occurs. If detected and treated early the disease can be controlled.
People with diabetes are also at risk of low vision. Reduced vision is one of the most distressing and difficult complications of diabetes.

Diabetes may cause damage to the eye’s light sensitive lining, the retina, and produce changes called diabetic retinopathy where the walls of the blood vessels are weakened.

These tiny blood vessels at the back of the eye begin to bulge and leak, oozing blood into the eye. Cellular changes can also cause fats and fluids to leak into surrounding tissue. Resulting damage to the eye can lead to permanent loss of vision.

“As the disease progresses, you will notice rapid changes in vision. There will be difficulty in achieving stable vision, sensitivity to glare and reduced night vision.

With regular examinations any threats to your sight can be detected and treated promptly, minimising the risk of permanent loss of vision.”

Research shows people with low vision are negatively affected in terms of independent living, quality of life, self-ranking of health, depression, falls and fractures. They are also likely to have increased need for community and/or family support and earlier institutionalised care.

Optometrists are the primary care providers to people with a wide range of eye conditions which require long term management as functional vision is reduced.

“For many of these people, the transition to low vision status is accompanied by the need for a range of low vision aids to maintain both health and safety.

“Most commonly, low vision patients are assisted by the use of a magnifier to enable them to read. Safety issues addressed include reading names and directions on medicines, reading key bills for payment such as electricity bills to avoid disconnection, reading safety instructions on appliances and checking oven settings and temperature to avoid stove fires,” Dr Frederikson says.

“The optometrist is able to prescribe the most suitable low vision aid based on clinical findings, but most low vision patients will need to ‘test drive’ a few magnifiers to settle on the best one for their needs and abilities.”

ENDS

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