Californian scientists have revealed a steroid-based compound, called lanosterol that can dissolve away cataract
Invasive surgery may no longer be required for cataract patients who wish to see clearly again. A team of researchers at the University of California, San Diego (UCSD) have developed a new drug that can be delivered directly into the eye through an eye dropper to shrink down and dissolve cataracts – the primary cause of blindness in humans.
The researchers believe that the naturally occurring compound, lanosterol, has the ability to dissolve the protein formations that cause cataracts to emerge. The Californian team claims that the treatment is long-term and, in some cases, permanent.
The effects have yet to be tested on humans, the team from the University of California, San Diego hopes to imitate the findings in clinical trials and offer an alternative to the only treatment that’s currently available to cataract patients – painful and often prohibitively expensive surgery.
Affecting tens of millions of people worldwide, cataracts cause the lens of the eye to become progressively duller, and when left untreated, can lead to total blindness. This occurs when the structure of the crystalline proteins that make up the lens in our eyes deteriorates, causing the damaged or disorganized proteins to clump and form a milky blue or brown layer. While cataracts cannot spread from one eye to the other, they can occur independently in both eyes.
The scientists first noticed the cataract-blocking properties of lanosterol in two Chinese children. Both the children had the hereditary form of a genetic transformation that blocked the production of the compound in their bodies. However, their parents did not show the mutation and, therefore, never developed cataracts. The researchers concluded that lanosterol had some link with the appearance of cataracts.
Scientists aren’t completely sure what causes cataracts, but most cases are related to age, with the US National Eye Institute reporting that by the age of 80, more than half of all Americans either have a cataract, or have had cataract surgery. While obnoxious, the surgical method to remove a cataract is very simple and safe, but many communities in developing countries and regional areas do not have access to the MONEY or facilities to perform it, which means blindness is expected for the huge majority of patients.
The team decided to carry out a further study – details of which have been published in the journal Nature – to study the function of lanesterol in cataract formation. They studied the effect of lanesterol in canines who had a naturally occurring form of the disease. It was observed that administering lanesterol cleared the vision of the dogs completely within six weeks.
Dr. Kang Zhang of the UCSD’s Shiley Eye Institute believes that if the clinical trial is successful, the eye drops will provide a first-ever non-invasive treatment option for people suffering with cataracts. Currently, the only treatment option available for cataract patients is surgical removal of the affected lens and replacing it with an artificial one.
According to the Fred Hollows Foundation, an estimated 32.4 million people around the world today are blind, and 90 percent of them live in developing countries. More than half of these cases were caused by cataracts, which mean having an eye drop as an alternative to surgery would make an incredible difference.
“This is a really comprehensive and convincing paper – the strongest I’ve seen of its kind in a decade,” molecular biologist Jonathan King from the Massachusetts Institute of Technology (MIT) told Armitage. While not allied with this study, King has been involved in cataract research for the past 15 years. “They discovered the phenomena and then followed with all of the experiments that you should do – that’s as biologically appropriate as you can get.”
The next step is for the researchers to figure out exactly how the lanosterol-based eye drops are eliciting this response from the cataract proteins, and to progress their research to human trials.
It is estimated that nearly 50 million Americans will have cataracts by 2050.
The results have been published in Nature.