A Surprising Pufferfish Secret Could Help Treat Lazy Eye

A recent MIT study is offering a new approach to treating one of the most common eye disorders: lazy eye.

Scientifically known as amblyopia, the disorder often occurs when an eye and the brain stop working together, with the brain resorting to supporting the other eye to compensate, leaving the amblyopic eye affected in the long term.

Affecting around 2-4 percent of the U.S. population, according to Johns Hopkins Medicine, premature children or those with developmental delays or a family history of lazy eye are most likely to be affected.

While current treatments—eye patches, atropine eye drops, corrective lenses, and surgery—focus on forcing the impaired eye to become more active, they are often only effective during childhood at preventing permanent damage. The proposed new treatment revealed by The Picower Institute for Learning and Memory at MIT could be potentially effective even in adulthood.

In the study—which is a continuation of Picower Professor Mark Bear’s decades-long research on amblyopia—MIT researchers anesthetized the retinas of the nonworking eye of mice suffering amblyopia. Then, using a toxin commonly found in pufferfish and porcupines called tetrodotoxin, the anesthesia essentially disables the mice’s eye for two days. Working as somewhat of a “reboot,” researchers saw a restored visual response in the subject’s brain.

In previous studies, Bear’s team anesthetized both eyes or the working eye only, both resulting in positive outcomes. However, the most recent trial focusing on only the affected eye hints at a promising new approach.

“It’s a pretty substantial step forward because it would be reassuring to know that vision in the good eye would not have to be interrupted by treatment,” said Bear in a press statement. “The amblyopic eye, which is not doing much, could be inactivated and ‘brought back to life’ instead.”

Still, further research is needed before the research translates to a treatment for human patients.

He added, “especially with any invasive treatment, it’s extremely important to confirm the results in higher species with visual systems closer to our own.”

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