UV-Cataract Connection

Research shines light on the UV-cataract connection

This year, when optometrists remind patients to don proper protection from the sun, they’ll have more research to lean on. A new study firms up the correlation between chronic sunlight exposure and the risk of cataract and other eye conditions.

Cataracts are currently the leading cause of blindness worldwide. In the United States alone, total cataract cases are anticipated to double—with a projected prevalence of more than 50 million incidences—by 2050, according to the National Eye Institute (NEI).

Previous studies have confirmed a correlation between sun exposure and risk for cataract, and now researchers from Case Western Reserve University in Cleveland, Ohio, have offered a detailed outline of the chemical changes UV light induces in the eye.

The study, funded in part by the NEI, found that UV light can damage lens proteins in a distinct way—called glycation—that is typically seen in cataract and in cells damaged by oxidative stress. Oxidative stress destroys proteins inside the lens of the eye, producing a cataract.

Using a mouse model, researchers tested the effects of UVA light on proteins and chemicals found in lens cells. They found that, in the absence of oxygen, UVA light can trigger a chain reaction. This reaction begins with amino acid derivatives called kynurenines and ends with protein glycation in the lens.

Fraser Horn, O.D., member of the AOA’s Sports Vision Section, looks forward to follow-up studies that dive deeper into the mechanism, but he believes “the research done on the role of glycation and oxidative damage is possibly our best insight into what is occurring and how we may be able to reduce and/or prevent some of this damage from occurring.”

Optometrists play vital role in patient awareness
Most people know sunlight can damage their skin. But not everyone is as well informed about the harm UV light can cause their eyes.

“There has been such good education to parents about the importance of utilizing sunscreen when children are outside and we need to make sure that the same culture develops for sunglasses,” Dr. Horn says.

In his own practice, Dr. Horn connects with patients individually and discusses how sun eyewear and UV protection can be integrated in their lives and the activities they enjoy doing outdoors.

His rule of thumb? “Every time you put on sunscreen, you should be putting on your sun eyewear. Just make it a habit.”

July is a great time for optometrists to educate patients about the risk factors, symptoms and treatment options for cataracts, as well as discuss the implications long-term exposure to UV radiation may have on cataract development.

Content shared from the American Optometric Assocation