Scientists have discovered a new chemical that could reverse cataracts, one of the leading causes of blindness. This new substance could be used in eye drops, greatly simplifying the treatment and making it accessible to the general population at a low price and without intrusive procedures.
A cataract is a clouding of the lens in the eye leading to a decrease in vision. It can affect one or both eyes, generally evolves slowly, and causes about 50% of all the blindness cases in the world. Cataract removal can be performed at any stage and no longer requires ripening of the lens – however, it is still a surgical process and can be quite expensive, and of course, people are always reluctant to have eye surgery. This is where this new treatment enters the stage.
Jason Gestwicki, PhD, associate professor of pharmaceutical chemistry at UCSF and co-senior author of a paper on the new research explains:
“Shortly after you’re born, all the fiber cells in the eye lose the ability to make new proteins, or to discard old proteins,” said Gestwicki, who has continued his work on cataracts at UCSF, where he joined the faculty about two years ago. “So the crystallins you have in your eye as an adult are the same as those you’re born with.”
Reported November 5, 2015 in Science, the newly identified compound is not the first one that can treat cataract, but it is the first one soluble enough that it can be incorporated in eye drops.
The group started with over 2000 chemicals that showed some potential, ultimately focusing on 12 that are members of a chemical class known as sterols. Sterols, also known as steroid alcohols, are a subgroup of the steroids and an important class of organic molecules. They occur naturally in plants and animals, with the most known sterol being, of course, cholesterol. Out of this dozen, they ultimately zoomed in on lanosterol.
Lanosterol was previously shown to clear out cataracts, but it had to be injected into the eye, so they assembled and tested 32 additional sterols, and eventually settled on one, which they call “compound 29.” Compound 29 can be used in drops, and can help not only in human cataracts, but also in that of dogs or other pets.
But there’s a chance that this study could have even more implications, as Gestwicki explains.
“If you look at an electron micrograph at the protein aggregates that cause cataracts, you’d be hard-pressed to tell them apart from those that cause Alzheimer’s, Parkinson’s, or Huntington’s diseases,” Gestwicki said. “By studying cataracts we’ve been able to benchmark our technologies and to show by proof-of-concept that these technologies could also be used in nervous system diseases, to lead us all the way from the first idea to a drug we can test in clinical trials.”
