Most of the time, people who have cataracts (protein clumps in the lens of the eye that blur vision) develop them with age, but inherited genetic mutations can also cause cataracts to form.
Currently, the only way to treat cataracts is to remove the cloudy lens and replace it with a clear artificial lens via eye surgery.
Scientists recently came up with an alternative, less invasive treatment that's still experimental: eye drops.
It may yet be a while before the eye drops are even tested in humans, but the specially formulated drops appeared to reduce the severity of cataracts in dogs, a team of scientists reported in Nature.
Ling Zhao of Sichuan University and colleagues were looking into why children were born with cataracts, and found some had a genetic mutation that meant they couldn't make a molecule called lanosterol, which is found in the lens.
To find out why not having this molecule around caused cataracts, the scientists tested what lanosterol did to the clumpy proteins that form cataracts. It turned out lanosterol broke the protein clumps apart in the lab.
When the scientists tested lanosterol eye drops on dogs with cataracts that had developed with age, they saw the eye drops made the dogs' lenses significantly clearer, seemingly dissolving their cataracts over six weeks.
Zhao, et al.
Six weeks of daily lanosterol eye drops turned a dog's cataract (before, left) clear (after, right).
These results are very preliminary - it's the first time anyone has tested lanosterol as a treatment for cataracts. Scientists are still uncertain on exactly how and why the eye drops seemed to work; if most people produce lanosterol normally, then why do we still get cataracts? There are many possible answers to this question, and the researchers will need more testing, eventually in humans, to see whether using lanosterol in this way is truly safe and effective.
But if further research continues to be promising, one day we could have a simple eye drop to treat a condition that now requires surgery.