Cataract breakthrough could eliminate need for surgery

Ageing can bring on many changes in your life – some good, others less so. One that definitely falls into the latter category is cataracts. This clouding of the eye’s lens occurs relatively commonly in people as they age. (Not exclusively, though. My now 30-year-old son was diagnosed with cataracts at the age of 23.)

The good (relatively speaking) news is that cataracts can be treated. The bad news is that treatment involves surgery. While not particularly invasive as surgeries go, it is an inconvenience and does come with some risks.

Now, however, there could be good news on the horizon. Researchers at the National Institutes of Health (NIH) in the US have identified a protein that actually reverses cataracts. This opens the door to the possibility of treating cataracts without surgery, which has long been a goal of scientists.

Cataract attack with RNF114

That a protein could help reverse cataracts is somewhat ironic. The clouding of the eye is in fact damaged proteins that clump together forming what is termed an ‘aggregated crystallin’ The protein damage occurs through natural ageing, with exposure to ultraviolet (UV) light also a factor.

But the NIH researchers have identified one particular protein that helps reverse the clouding process. The protein is named RNF114, and its potential is discussed in a study published in the Journal of Clinical Investigation. It is more fully described by the authors as “the RNF114 complex, a newly identified CRYAA-related E3 enzyme”.

In an intriguing twist, RNF114 does its best work in hibernating animals, during the period they emerge from hibernation. “We identified a reversible lens opacity phenotype in ground squirrels associated with their hibernation-rewarming process,” the study’s authors wrote.

Ground squirrels are the stars of this cataract research – specifically, a squirrel that’s known as the ‘13-lined ground squirrel’. (Twelve-lined squirrels clearly don’t cut it!)

When these little critters go into hibernation, they undergo a cyclical change of metabolic state (as do many hibernating animals). This involves a decrease in body temperature, from the awake state (roughly 37°C) to the torpor state (roughly 4°C).

With the drop in temperature to 4°C during hibernation, the lens of the ground squirrel becomes cloudy. However, the lens quickly turns transparent after rewarming to 37°C.

Temperature change is not the only contributing factor, though. The lenses of non-hibernating animals (in this case, rats), which clouded at 4°C, remained opaque for a long time after rewarming to 37°C (eight hours). The study’s authors suspect that the RNF114 protein also played a part.

Balancing proteins

To confirm this, the researchers looked at what’s known as the ‘ubiquitin-proteasome system’ (UPS), a complex network that controls the balance and level of proteins in the cells of mammals. 

By introducing RNF114 into the UPS of rats, they were able to test “the reversibility of cold-induced lens opacity in non-hibernators”. With the inclusion of RNF114, the UPS promotes the degradation of the aggregated crystallin that causes cataracts.

At this point you might be tempted to point out that 13-lined ground squirrels are not the same as humans. And you would, of course, be correct. That obviously means that we’re a long way from using similar methods to treat cataracts in humans.

However, as the authors wrote, their research does demonstrate “great promise for cataract clinical applications”. Which means that an effective non-surgical treatment for cataracts may soon be – dare we say it – in sight.

Have you or someone you know been treated for cataracts? What was your experience like? Let us know via the comments section below.

Also read: New ‘Eye Connect’ service a sight for sore eyes

Health disclaimer: This article contains general information about health issues and is not advice. For health advice, consult your medical practitioner.