Antidepressant drug could help save sight of millions

AN ANTIDEPRESSANT drug could help stop millions of people losing their sight from one of the biggest causes of blindness in the world.

Scientists believe they have found a new treatment that could help prevent vision loss from macular degeneration.

The discovery was made when researchers found a way to stop abnormalities that cause the degeneration of the macular, the light-sensitive area at the back of eye. In tests on mice using drugs that are already on the market, experts discovered they could prevent damage to the cells.

Macular degeneration is the fourth most common cause of blindness behind glaucoma, cataracts and preterm birth and is divided into “dry” and “wet” forms, with the dry form making up 90 per cent of cases.

The condition has affected about 600,000 Britons and more than 13 million people worldwide, mainly among the elderly, and is largely untreatable.

Prof Aparna Lakkaraju, from the University of Wisconsin-Madison in America said: “These studies raise the possibility of treatments that could slow or prevent macular degeneration.”

In the study, published in the Pro- ceedings of the National Academy of Sciences, researchers pinpointed how immune abnormalities beneath the retina result in macular degeneration.

Prof Lakkaraju focused on two protective mechanisms during the gradual onset of macular degeneration.

The more common dry form, which can take years to develop, is caused by a build-up of deposits on the macular. The wet form, which affects around 40,000 people, develops when abnormal blood vessels form underneath the macular and damage cells.

Prof Lakkaraju said the process starts with injury to the retinal pigment epithelium (RPE), which is protected by the protein CD59,

The researchers used cells from pig eyes and mice that lack CD59 to identify an enzyme that neutralises the attack on the eye cells. The enzymes are commonly found in drugs used to treat depression and osteoporosis.

Prof Lakkaraju said: “We found that the antidepressant desipramine, administered to mice in their drinking water, restored CD59 on the cell surface, decreased reactive oxygen species, and prevented mitochondrial fragmentation.”