WORLD RETINA DAY: Saturday September 27
WORLD RETINA DAY: Saturday September 27
25 September 2003
Spotlight On Retinas
PC George Gutteridge of the Essex Constabulary was murdered in a country lane on September 27, 1927.
September 27, 2003 is designated World Retina Day. The two events have more in common than the coincidence of date.
PC Gutteridge had stopped a stolen car, but he was killed by a revolver – shot twice in the side of the head and then through each eye. His killers’ barbaric actions were attributed to their belief – current at the time, but false – that the last thing anyone saw would be photographically recorded by their retinas.
“We’ve learned a great deal more about retinas in the 76 years since that grisly murder – too late to help George, but enough to know how vital a role they play in our sight and how important it is we look after them,” says Dr Lesley Frederikson, national director of the New Zealand Association of Optometrists.
The retina is a coating of light-sensitive tissue at the back of the eye. As light enters the eye through the pupil it is focused onto the retina by the lens. Retinas are hot-wired through the optic nerve to the brain, which interprets the images it receives from the retina. The most important part of the retina is a small area at the centre called the macular, which gives the central, detailed vision used for reading, driving, and recognising faces.
“Think of your eye as a camera and the retina as the film - except that the retina cannot ‘hold’ an image for processing later in the way a film does, despite what George’s killers thought. The processing is done on the spot by your brain,” Dr Frederikson says.
The purpose of World Retina Day is to alert people to the fact things can go wrong with their retinas, leading to blindness if not immediately treated.
“Retinas can tear, or detach from the eye, as a result of eye or head injury. Retinal detachments can also occur spontaneously in people with high myopia (short sight). They are completely painless; symptoms are a marked increase in the number and size of "floaters" (the little black spots most of us see moving about in our eyes), flashes of light inside the eye, and/or the loss of part of your vision as if someone had pulled a curtain over the eye.”
Dr Frederikson says anyone experiencing these symptoms should see an optometrist immediately.
The most common condition affecting the retina is macular degeneration, the leading cause of sight loss in the western world. As it is related to ageing, it is usually referred to as age-related macular degeneration or AMD, but it occasionally affects younger people. It too is painless, Dr Frederikson says, but can cause progressive loss of central vision.
“Symptoms are distorted vision - door frames or any straight lines look wavy - and also blurring of anything directly in front of you, near or far away. The earlier macular degeneration is diagnosed the better the chances are of slowing its progress.”
There are also a number of hereditary conditions which affect the retina, such as retinitis pigmentosa, which leads to a gradual loss of peripheral (side) vision, and Stargardt's - a form of macular degeneration which affects younger people. And people with diabetes need to get their eyes screened every year because blood vessel changes in the retina can lead to retinal haemorrhages and blindness.
Just like other parts of the body, everybody's retinas become more vulnerable with age. The NZAO says regular eye exams are important for the 40-plus age group, and the over-60s should have their eyes examined every two years.
“Whatever your age and general state of health, you should get your eyes examined if you notice any changes in your vision,” Dr Frederikson says. “This will enable your optometrist to pick up early symptoms of any sight-threatening condition and refer you to an eye specialist (ophthalmologist) if need be.”
You can help keep your retinas healthy by looking after your own health - eating green leafy vegetables like silverbeet and spinach, and seafood (for zinc); going easy on fatty foods, not smoking, exercising to improve circulation and help keep weight and blood pressure down, wearing sunglasses to protect your eyes from UV rays, and always using any protective headgear required for sports or work.
Further information about the Gutteridge case is on the website of the Essex constabulary.