Injection restores sight
  • Thu, 07/26/2012 - 2:59pm

A new study revealed that a chemical injection into the eye could help restore sight to patients with inherited or acquired blindness.

Scientists from the University of California, Berkeley, the University of Munich, and the University of Washington in Seattle worked together to develop the chemical AAQ, which repaired sight in blind mice.

Researchers found that injecting small amounts of the chemical compound into the eyes of blind mice resulted in pupil contractions when exposed to bright light. The mice also exhibited light avoidance, a common reaction in rodents that would not have occurred without the ability to detect light.

The scientists gave the mice genetic mutations that caused the rods and cones in their eyes to die soon after birth. According to MedicineNet, rods and cones facilitate peripheral and central vision in the retina and light activates them.

This simple injection may benefit patients with illnesses such as retinitis pigmentosa or age-related macular degeneration. MedicineNet defines retinitis pigmentosa as an inherited degenerative condition in which person’s rods and cones deteriorate and die, causing severe vision problems and eventual blindness.

Age-related macular degeneration develops as a person ages and affects a small, light-sensitive portion of the retina, called the macula, according to MedicineNet. In age-related macular degeneration, the macula slowly deteriorates, making it difficult for a person to do tasks that involve sensitive, sharp vision such as reading or driving.

The chemical AAQ binds to protein ion channels on the outside of the retina cells. According to MedicineNet, ion channels act as gateways, allowing certain ions to pass in and out of cells.

Researcher and professor of molecular and cell biology from the University of California, Berkeley, Richard Kramer said that the chemical makes the “blind” cells in the retina light-sensitive. When triggered by light, AAQ changes the movement of the ions through the channels to communicate with neurons in the brain, similar to the normal function of healthy rods and cones.

The chemical compound poses an advantage to patients because the injection does not irreversibly alter the retina and it can be discontinued if desired. The procedure is also less invasive than other treatments, some of which require inserting light-sensitive chips into the eye.

The team of researchers hopes to refine the chemical through more tests in rodents to eventually help people with degenerative blindness regain sight.




About the Contributor

Jessica Davids
I report on FDA developments and new pharmaceutical launches, risks, and safety concerns.

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