Easier test for blindness cause
Scientists from Australia’s Vision Centre have demonstrated a quick, accurate test under lights for one of the world’s leading causes of blindness.
A new study shows that age-related macular degeneration (AMD) can be just as effectively and more rapidly and inexpensively diagnosed under bright lights, instead of requiring patients to sit for 20 minutes in a darkened room.
“AMD accounts for half of the legal blindness cases in Australia,” says Professor Ted Maddess from The Vision Centre and The Australian National University. “It affects one in seven people over the age of 50, costing the nation $2.6 billion a year. Globally, it affects 25 to 30 million people, with an annual cost of $343 billion.
“While current tests for AMD are done in the light, scientists have proposed that it might be better if the patient has their vision adapted to the dark prior to the test,” he says.
“This is because they had found that rod receptors – vision cells that we use to see in black and white and in low light – die earlier in AMD than the cone receptors we use to see in colour during the day. So it had been suggested that AMD tests would be more accurate if they were based on the health of a person’s rods.”