New eye chart to help prevent sight loss in elderly: New Zealand researchers

A new eye chart test could help save the eyesight of elderly people, New Zealand researchers involved in its development said Thursday.

The chart developed by researchers in New Zealand and Britain could help in the early detection of age-related macular degeneration (AMD), a leading cause of blindness in the developed world.

The chart used "vanishing" letters, where each letter is made up of a black core with a white surround, and was more sensitive than a conventional chart at detecting loss of vision in 80 patients with AMD, according to a study.

"More new treatments for AMD are becoming available, each capable of slowing the progression of the disease and allowing patients to make the most of the vision they have," Professor Steven Dakin of the University of Auckland, said in a statement.

"As such treatments cannot currently restore vision it is critical that AMD is detected early in order to produce the best outcome for patients."

The early signs of AMD could be subtle and might not be picked up by a traditional eye test until the condition had got quite bad.

"The design of the new charts is such that letters that are too small to read, appear to vanish," said Dakin.

"This means that your score on this chart is limited not just by your ability to read the letters, but by your ability to tell they are even there."

AMD caused retinal cells to die and seemed to affect patients' ability to read the letters more than their ability to spot them.

"These patients perform worse on the new chart even though they might still be able to read conventional eye charts," said Dakin. Endit