Chemical restores some sight in blind mice

Scientists have discovered that a chemical photoswitch called AAQ has the ability to temporarily restore some vision in blind mice. The research team is now working on developing an improved compound that may someday restore vision in people with blindness caused by retinitis pigmentosa and age-related macular degeneration. Both conditions result in the death of light-sensitive cells in the retina, leaving the eyes with no functional photoreceptors. AAQ, remedies this by making the remaining, naturally “blind” cells, sensitive to light. It does this by binding to protein ion channels on the surface of retinal cells. AAQ is a photoswitch, so when exposed to light, the flow of ions is changed and the neurons activated. “The advantage of this approach is that it is a simple chemical, which means that you can change the dosage, you can use it in combination with other therapies, or you can discontinue the therapy if you don’t like the results,” said lead researcher Richard Kramer.