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A long-forgotten treatment for alcoholism could bring new hope to millions suffering from degenerative blindness. US researchers have found that disulfiram, better known as Antabuse, can improve vision in nearly blind mice.

Losing sight to a degenerative retinal disease, such as age-related macular degeneration (AMD) or retinitis pigmentosa (RP), has long been seen as irreversible. For patients, existing therapies can only slow the disease’s progress but never restore vision. Yet, a 2022 study published in Science Advances challenged this assumption: disulfiram (Antabuse), a decades-old anti-alcoholism drug, may reopen the path to light.

Traditionally, Antabuse is known for its deterrent effect: causing hot flashes, nausea and palpitations if alcohol is consumed. Its mechanism seemed to have no connection to vision. Yet researchers from University of Rochester, UC Berkeley and UC Santa Barbara showed that it could partly restore sight in mice with advanced retinal degeneration.

The mechanism is fascinating: Normally, when the photoreceptors (light-sensitive cells located in the outer retina) disappear, the inner retina becomes disrupted. Deprived of normal signals, the inner retina produces constant electrical “noise,” drowning out what little visual information remains even before it reaches the brain. As a result, even the few signals still transmitted by surviving photoreceptors are lost in this chaos.

This is the precise noise that disulfiram targets. Disulfiram blocks the biochemical pathway fueling this noise, clearing the way for surviving signals to reach the brain. In tests, nearly blind mice that could not distinguish simple shapes suddenly regained the ability to perceive images after treatment. “It was like lifting a fog that masked the last rays of light,” one researcher said.

Unexpected Breakthrough, Yet Caution Is Required

The findings sparked worldwide excitement: AMD and RP are leading causes of blindness, with more than 200,000 people in Europe alone losing their vision each year. A cheap, readily available drug could be a game-changer if proven safe and effective in humans.

Yet caution is essential. So far, the effect has only been observed in animal models; no clinical trial has yet been conducted on humans. Moreover, disulfiram carries a major drawback: severe side effects if alcohol is consumed. This immediately limits its use as a long-term treatment for older populations, among whom abstinence cannot always be guaranteed.

Scientists stress that the real breakthrough lies not in prescribing Antabuse itself, but in understanding its mechanism. By targeting the same biochemical pathway, future drugs could reproduce its benefits without the risks. “We have opened a completely unexpected therapeutic door,” explains lead researcher Machelle Telias. “From here, we can design safer treatments that may truly restore sight in patients once thought incurable.”

This discovery highlights a growing trend in biomedical research: drug repurposing. Instead of starting from scratch, researchers explore new uses for existing, approved medications, thus saving time and cost. In this case, a drug once designed to fight alcoholism may become an ally against blindness.

The potential is enormous. If confirmed by clinical trials, it could mark the first therapy to not only slow but also restore vision in advanced retinal degeneration – an unimaginable prospect until now for patients and their families.

Research teams are preparing small-scale human trials in AMD and RP patients with partial vision, to test tolerance, efficacy and optimal dosages. The road ahead is long, but hope is back on the horizon.

As is often the case in science, the discovery arose from an unexpected intuition: exploring an old, unassuming drug to treat a seemingly unrelated condition. What if the future of vision lay hidden in a pill invented over 70 years ago to discourage drinking?