Age-related macular degeneration (AMD) and retinitis pigmentosa (RP) are common causes of visual impairment and blindness, affecting hundreds of millions globally. Both diseases progress very slowly, over years and even decades, yet typical vision restoration technologies are usually deployed in the latter stages of retinal degeneration. This leaves a significant gap in treatment for those whose sight has not yet completely deteriorated. 

Could a drug used to help people stop drinking improve sight for millions of patients with severe visual impairment? This question is being explored by a team of researchers at the University of California, Berkeley and Santa Barbara.

What the Researchers Did

In the retina, rods and cones are receptor cells that convert light into electrical signals for the brain to decode, giving us sight. Previous research has demonstrated that when these rods and cones deteriorate, they release retinoic acid (RA), exciting retinal ganglion cells that process light into visual information and transmit it to the brain. This hyperactivity interrupts the visual process.

To combat this, the researchers employed the drug disulfiram, or Antabuse, which is known to have a dual function: inhibiting the enzyme that breaks down alcohol, as well as the enzyme that makes retinoic acid.

• The researchers experimented with disulfiram on mice with inherited retinitis pigmentosa.
• When the mice were young mice and still had healthy vision, they were trained to recognize a basic black and white computer image.
• The mice were divided into a disulfiram treatment group and a placebo group.

What They Found

Published in Science Advances, the researchers found that when the mice’s vision declined, those treated with disulfiram still reacted to the image, even though blurry, whereas the placebo group did not respond.

According to study author Richard Kramer of UC Berkeley’s Department of Molecular and Cell Biology, vision in mice receiving disulfiram was better than in mice receiving a placebo.

What the Findings Mean

Since progression of AMD and RP is very gradual, he said, “[t]here may be a long window of opportunity in which suppressing retinoic acid with drugs like disulfiram could substantially improve low vision and make a real difference in people’s quality of life.”

The drug isn’t intended as a permanent solution, Kramer continued, “but right now there are no available treatments that even temporarily improve vision.” The therapeutic strategy of inhibiting RA could be applicable to a wide range of photoreceptor degenerative disorders.

Disulfiram is already approved by the U.S. Food and Drug Administration.

*Powell, S. (2022, March 22). Could a treatment for alcoholics help people with vision loss? Optometry Today. https://www.aop.org.uk/ot/science-and-vision/research/2022/03/22/could-a-treatment-for-alcoholics-help-people-with-vision-loss