AMD: Invention better than a poke in the eye
Invention better than a poke in the eye
Danny Rose, AAP Medical Writer
March 3, 2011
It's better than a poke in the eye with a sharp needle.
An Australian invention which could do away with the need for injections into the eyeball to treat a common vision problem is about to be tested in humans.
People with the treatable form of age-related macular degeneration (AMD) are now required to have monthly injections into each affected eye to preserve their sight.
"Nobody likes to have an injection in the eye, and not only once but every month," said Melbourne-based Dr Harry Unger, an ophthalmologist who has developed the SonoEye.
"And sometimes if they have got it (AMD) in both eyes ... these patients would do anything not to have an injection."
Testing of the SonoEye is well advanced, and it has shown capable of delivering medication to the inside of the eyeball.
Instead of a needle, the device uses waves of ultrasound which first liberate the medicine from a special gel and then push it through the surface of the eye.
The drug then gets taken up and circulates through the tiny blood vessels in the eye, reaching even the retina at the back of the eye.
It is a relatively painless process that is over within minutes, and does not carry the same infection risk and need for anaesthetic that an injection does.
The injections also can also result in a blood vessel haemorrhage or detachment of the retina leading to, ultimately, a loss of sight.
"All of those potential side-effects disappear if you can get the drug in without sticking a needle in the eye," Dr Unger said.
"The ultrasound vibrates the drug from being bound to being released and pushes it towards the surface of the eye, where the blood vessels inside the eye carry it to where it needs to be.
"The patient will hardly be aware of it, and they won't need an anaesthetic," he said.
AMD is the leading cause of blindness and severe vision loss in Australia, where one in seven people aged over 50 will develop a form of the disease.
Its "wet" version - so called because it involves leakages out of the tiny blood vessels in the eye - is treatable.
The National Health and Medical Research Council has provided two-year $190,000 grant that will allow Dr Unger's company Seagull Technologies, in a partnership with the Centre for Eye Research Australia (CERA), to undertake further testing.
They plan to launch a human trial in 2012 which will involve a small number of AMD patients.
Dr Unger said because the technology involved a new method to deliver existing drugs, he did not expect a drawn-out process to have the SonoEye approved for clinical use.
It could be available to patients within a year to 18 months after successful human trials.
There was also "huge potential for the underlying technology", he said, and while the focus was now on eyeballs there were other areas of the body where it could also be used.
"Anything with a mucus membrane that you can get to," Dr Unger said.
"Like the inside of the mouth, the urethra, the vagina, cervix, potentially is a local target for drugs that currently you have to give intravenously."
© 2011 AAP
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