Eye Health

Updated 11 November 2015

Eye drops could cure cataracts and long-sightedness

Cataract surgery could soon be a thing of the past. At least that’s what two recent studies, one published in Nature and the other in Science, suggest.

0

Cataracts are cloudy regions that develop in the lens of the eye. They take years to form, but can be dissolved in a matter of weeks with a substance called lanosterol, a precursor to cholesterol and several related sterols.

The Nature paper showed that an injection followed by eye drops containing lanosterol reversed clouding in the lenses of dogs after treating them for just six weeks. Veterinarians may soon be able to substitute eye drops for the scalpel to treat their canine patients, which is just as well as cataracts are common in some pedigree dogs including, ironically, guide dogs for the blind.

Read: Boost your eye health with vitamin C

The Science paper reports the discovery of a class of small molecules also derived from cholesterol. These sterols were shown to reverse lens clouding in mice and, remarkably, the effects were seen in just two weeks.

Surgeon shortage

Cataracts and the clouding that happens as a result of protein aggregation was considered a point of no return. Until these two new studies came along, no one even thought that restoring the transparency of the lens was an alternative.

These papers change that perspective and open a completely new therapeutic strategy to treat cataracts in the future. Cataracts occur as a result of protein clumping together on the eye’s lens, preventing light from reaching the retina.

Once the cataract is formed, there is one option: surgery. Cataract surgery involves removing the natural lens through tiny incisions and replacing it with a plastic “intraocular” lens.

Read: Not the end of the world for cataract patients

Cataract surgery is one of the most commonly performed procedures and it has a high success rate. The problem is that there simply aren’t enough ophthalmic surgeons to perform all of the procedures that are needed.

In 2010, there were 95m people requiring cataract surgery, worldwide, and of these people 20m were blind as a result. With people living longer, the problem is only going to get worse.

If you live long enough, you will develop cataracts. So something that radically shifts not only our understanding of cataracts but also its treatment is badly needed.

And the two recent studies may be just that something. They herald the most remarkable discovery to emerge in the field of cataract therapies since Harold Ridley developed the intraocular lens in the mid-20th century.

It's not just cataracts

The Science paper shows that selected sterols could help in the treatment of a host of other human diseases such as cardiomyopathy and neurodegenerative diseases where similar proteins are involved. As more details on the mechanism of action become known, it is possible that such sterol-based drugs could have applications for the treatment of Parkinson’s disease, Alzheimer’s disease and other types of dementia.

Read: How antioxidants can slow down vision loss

Another possible application for sterol-based treatments is presbyopia (long-sightedness). This is the other universally experienced ageing effect on the eye lens.

When we reach middle age, our arms need to grow a couple inches every year so we can continue to type and read the computer screen. It is believed that presbyopia is the first stage in age-related cataracts.

By mid-life, the lens proteins have accumulated significant damage, enough to change their properties and start the process of forming “aggregates” that eventually become a cataract. So the research described in the two papers really does offer something momentous: the preservation of our sight as we age.

Read more:

102-year-old KZN woman can see again after cataract surgery

Eye health documentaries launched to combat blindness in Zambia

HelpMeSee has restored sight for 200,000 cataract sufferers

Image: Ederly man being receiving eye drops from iStock

Roy Andrew Quinlan, Professor in the school of biological and biomedical sciences, Durham University

This article was originally published on The Conversation. Read the original article.

The Conversation is a collaboration between editors and academics to provide informed news analysis and commentary that’s free to read and republish.

 

Ask the Expert

Optometrist

Megan Goodman qualified as an optometrist from the University of Johannesburg and is currently practising at Tygerberg Academic Hospital in Cape Town. She has recently completed a Masters degree in Clinical Epidemiology at Stellenbosch University. She has a keen interest in ocular pathology and evidence based medicine as well as contact lenses.

Still have a question?

Get free advice from our panel of experts

The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.

* You must accept our condition

Forum Rules