Australia's Leading Ophthalmic Magazine Since 1975

     Free Sign Up     

Australia's Leading Ophthalmic Magazine Since 1975

     Free Sign Up     
News

Glowing contacts could help treat diabetic retinopathy

30/05/2018By Matthew Woodley
A team of researchers has developed luminescent or glow-in-the-dark contact lenses, which they believe could help protect against eye damage due to diabetic retinopathy (DR).

Mr Colin Cook, a graduate student from the California Institute of Technology (Caltech), and his team designed contact lenses that reduce the retina’s night-time oxygen demand by giving rod cells the faintest amount of light to look at while the wearer sleeps.


“Your rod cells, as it turns out, consume about twice as much oxygen in the dark as they do in the light. If we turn metabolism in the retina down, we should be able to prevent some of the damage that occurs.”
Colin Cook, Caltech

Rod cells need and use much more oxygen in the dark than they do when they’re awash with light, and it has long been hypothesised that much of the damage caused to the retina by diabetic retinopathy occurs when the rod cells crank up their oxygen demands at night.

Cook said because damage to the retina begins with an insufficient supply of oxygen, it should be possible to stave off further eyesight loss by reducing the retina’s oxygen demands.

“Your rod cells, as it turns out, consume about twice as much oxygen in the dark as they do in the light,” he said.

“If we turn metabolism in the retina down, we should be able to prevent some of the damage that occurs.”

The contact lenses, mimicking a technology from wristwatches with luminescent markers on the plate face, are made of tiny vials filled with tritium to provide the light source throughout the lifetime of the lenses.

The size of the tritium-filled vials is about the size of a few strands of human hair and arranged in a radial pattern that creates a circle just big enough to fall outside of the wearer’s view when the pupils are constricted in lighted conditions.

However, in the dark, the pupil expands, and the faint glow from the vials can illuminate the retina.

The lenses are placed on the surface of the eye together with the light source so that when the eye moves the light source moves with it and prevents the wearer from seeing a flicker of light, which can be distracting.

“There’s neural adaptation that happens when you have a constant source of illumination in the eye. The brain subtracts that signal from the vision and the wearer will perceive dark again in just a few seconds,” Cook said.

Early testing in collaboration with the University of Southern California has shown promising results, with rod cell activity decreasing by as much as 90% when worn by test subjects in the dark.

In the next few months, Cook and his team will start testing the lenses to see if their ability to reduce retinal metabolism will translate into the prevention of diabetic retinopathy. Following those tests, they will seek FDA permits to begin clinical trials.



Editor's Suggestion
Hot Stories

AND/OR
 

Subscribe for Insight in your Inbox

Get Insight with the latest in industry news, trends, new products, services and equipment!