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Can Eye Drops Really Cure Cataracts?

Cataracts account for about half of all cases of blindness in the world. What’s worse, almost all of us will develop cataracts eventually, as long as we live long enough –the vast majority of the population will get them at least by their eighties or nineties. While cataracts can be treated with surgery, for much of the developing world this isn’t a realistic option. There are still 18 million unnecessarily blind cataract patients globally who haven’t yet received care, and while organisations like our own TejKohli Cornea Institute are aiming to reduce that figure dramatically, we need to be looking for other, more innovative options than surgery alone. After all, while surgery is relatively easy for Western countries with good infrastructure and a high per capita net worth, developing countries aren’t likely to have those advantages for some time. So what else can we employ in the fight against cataract blindness?

We’ve been very intrigued by recent developments in the field, in particular recent research into developing a genuine eye drop cure for cataracts – that means no surgery, making it easy to distribute even in remote villages in the developing world.Eye drops don’t require dense domestic infrastructure – just think about the difficulties involved in getting enough trained surgeons to developing countries to carry out the surgery, as against the possibility of simply making the eye drops in the West and exporting them to the countries that need them. If we really could find an eye drop treatment that would cure cataracts, the distribution and administration of cataract treatment would become far easier, and could mean a real practical breakthrough in beating the disease.

But how realistic are these claims of an eye drop cure for cataracts? Scientists at the University of California, San Diego have been conducting studies based on a certain natural chemical already present in the human body, the steroid lanosterol. Their research, which was published in Nature, was based on the discovery that, in some cases, cataract blindness seems to be correlated with a genetic mutation which inhibits lanosterol production. Hypothesising that increasing the lanosterol could have an effect on cataracts, the scientists proceeded with animal testing on dogs suffering from cataracts. And the scientists did indeed find that lanosterol was able to significantly reduce the size of the cataracts, sending them from severe to mild or gone completely.

The treatment was not quite as simple as an eye drop, though – lanosterolnano-particles first had to be injected into the vitreous cavity (a space at the back of the eyeball). That does take some of the wind out of our sails, since clearly having to use the injection in a practical context would make administering the treatment harder than simply using eye drops. But it is an important step forward, away from invasive surgery, and we remain intrigued by the possibilities that eye drop treatments could hold for treating cataract blindness in the developing world. But for now, it remains to be seen whether we’ll be able to fulfil the potential that the treatment offers.