Eye drops to treat cataracts?
Blog Vol 7.9. Eye drops to treat cataracts?
One could say that the “Holy Grail” in eye care would be to find a drop that cures cataracts. The World Health Organization estimates that over 65 million people worldwide suffer from blindness due to cataracts. Presently the only cure is cataract surgery, an involved medical procedure that requires huge resources both in skill and infrastructure. Developing a drop that reverses cataracts would be a boon to people in parts of the world that have little access to surgery.
Cataracts are opacities that occur in the lens of the eye, usually over time.
What is remarkable about the lens in the eye is that it is derived from surface ectoderm in the womb, AND you can see through it, AND it is stable for most of our lives. Because there is no vascular supply to the lens, there are limited resources for protein synthesis making it susceptible to degradation. Fortunately, the lens has crystallin proteins that help to keep tissue integrity. One such protein, αB-crystallin (cryAB), acts as a chaperone to maintain protein stability and transparency. Changes to this protein over time result in cataracts.
Finding a substance that could slow down or even reverse the changes to this chaperone protein would be a real help in cataract treatment. Researchers came up with a lanosterol (a naturally occurring steroid) eye drop in 2015 which binds to cryAB and helps the protein continue to do its job. Unfortunately, this drop needed to be injected because it did not penetrate the cornea very well.
More recently, researchers have come up with an oxysterol (a derivative of cholesterol) eye drop, scientifically called 5-cholesten-3β,25-diol, which penetrates the cornea (no injection necessary), binds to the cryAB, and helps maintain lens protein integrity. (Read more here).
Oxysterol is in double blind studies right now and seeking governmental regulatory approval. This is a promising treatment that can provide help for many people suffering from cataracts who do not have access to surgery. Surgery, where available, is still the treatment of choice and is likely to remain that way. None of us want eye surgery; the idea of a non-surgical solution to cataracts is very appealing, but these drops just do not result in the same clarity of vision.
At the present time, regular eye visits, a balanced diet, regular exercise, reduced exposure to UV light, and stopping smoking are the only ways we can prevent cataract development. You all know the drill, not very glamorous, no easy solutions.
‘til next week,
The good doctor
