Something good to say about cholesterol

Cataracts are a clouding of the lens in the eye.

Drug treatment for cataract is back in the news this week. We reported in July on the Chinese/USA researchers who managed to reverse cataracts in elderly dogs using a substance that’s related to cholesterol. Now a second team has found a new cholesterol-related substance that can do the same job in mice and in human tissue. Fight for Sight researcher Prof Roy Quinlan has written a comment for the current issue of Science looking at what the two studies mean.

In short, the fact that lanosterol (from July’s study) and the substance known as 29 (also related to cholesterol) can both reverse cataract backs up some previous hints. Cataracts are a feature of certain rare developmental disorders that mean the body doesn’t process cholesterol normally. Then there’s the known slight increase to the risk of cataract from taking statins to lower cholesterol.

So all of this information points to a route to non-surgical treatment for cataract in humans that could potentially be very effective. It may even lead to breakthroughs in developing drugs for other conditions that involve an unhealthy build-up of protein (as happens in cataract).

This is because the way Makely and team picked out substance 29 got over a technical barrier: they showed that it is possible to test lots of candidate drugs on proteins that don’t have many targets for a drug to work on. This is something that’s common to conditions such as Parkinson’s and Huntington’s as well as cataract.

Yes, but how does it work?

There’s still quite a way to go yet. We don’t know enough about exactly how the cholesterol-related treatments work. This is really important given cholesterol’s links to heart disease. But projects like our current grant to Dr Sergi Garcia-Manyes at Kings College London should help us understand more about the best approach to reversing and preventing cataract.

This is a top priority for research as identified by the Sight Loss and Vision Priority Setting Partnership of eye health professionals and people affected by cataract. It’s a long process but we are getting there. And we know it can’t come too soon for the millions worldwide who are blinded through lack of access to surgery.

In the UK, 300,000 safe and successful NHS cataract operations are done each year. But wouldn’t it be great if there was no need for surgery and the NHS could save the money. Cholesterol might claw back its bad reputation yet.