An eye drop tested on dogs suggests that cataracts, which responsible for half the blindness cases worldwide, could one day be cured without surgery, a study showed and reported in Nature.
A naturally occurring molecule called lanosterol, administered with an eye dropper, shrank canine cataracts.
Today, the only treatment available for the debilitating growths is going under the knife. Surgery is usually simple and quite safe, but it prohibitively costly. Fewer than 10 out of 100 people have complications from cataract surgery but it does at times involve the risk of partial to total vision loss.
Surgeries in eye camps in developing countries have been known to even lead to blindness.
The research began with two children — patients of lead researcher Kang Zhang of Sun Yat-sen University in Guangzhou — from families beset with a congenital, or inherited, form of the condition. They discovered that the patients shared a mutation in a gene critical for producing lanosterol, which the researchers suspected might impede cataract-forming proteins from clumping in normal eyes.
In a first set of lab experiments on cells, they confirmed their hunch that lanosterol helped ward off the proteins.
In subsequent tests, dogs with naturally occurring cataracts received eye drops containing the molecule.
After six weeks of treatment, the size and characteristic cloudiness of the cataracts had decreased, the researchers reported.
“Our study identifies lanosterol as a key molecule in the prevention of lens protein aggregation and points to a novel strategy for cataract prevention and treatment, ” the authors concluded.
“These are very preliminary findings, ” said J Fielding Hejtmancik, a scientist at the US National Eye Institute, who wrote a commentary also published in Nature.
“Before there are any human trials, the scientists will probably test other molecules to see if they might work even better, ” he said by telephone.
The preliminary results, he added, “don’t mean that lanosterol is the only or the best compound” to reduce cataracts.