A team of Chinese researchers have published their study on the Nature Communications journal, revolving around the prototype of a smart drug-releasing contact lens – results of which show great potential in treating glaucoma.
Glaucoma is a progressive and degenerative eye disorder wherein the optic nerve (responsible for transmitting visual signals to the brain) gets damaged, usually due to increased intraocular pressure (IOP). If it worsens, glaucoma can lead to vision loss, and it has been known to be the leading cause of blindness for people over 60.
According to Novartis Healthcare Philippines, a research-based pharmaceutical company, almost 300,000 Filipinos suffer from glaucoma, and around 80 million people are affected worldwide by the condition , according to the World Glaucoma Association.
Now, electrical engineer Cheng Yang and Xi Xie of Sun Yat-Sen University together with their colleagues have come up with a model for a wireless contact lens device that has the ability to detect a rise in intraocular pressure and consequently send send signals to activate the delivery of brimonidine, a pressure-lowering drug, towards the cornea.
How It Works
- Detection: Six tiny copper plates are set around the outer and inner contact lenses in a cantilever structure. As the pressure inside the eye rises, the gap between the lenses decreases, and the pressure sensors then detect this rise in IOP.
- Transmission: An integrated antenna transmits this data to a nearby device or computer, which then signals the inner layer of the lens to do its job.
- Release of Medication: Upon receiving a go signal, the lens’ inner layer releases the brimonidine from a hydrogel attached to an electrode, towards the eye’s cornea region.
The researchers have successfully tested their prototype ex vivo (using pigs’ eyeballs) and in vivo (utilizing rabbits’ eyes) – both setups displayed positive results.
Results of the in vivo experiment showed that the rabbits’ eye pressure decreased by a third within 30 minutes after drug release, and by more than 40 percent on average after 2 hours.
The wireless theranostic (therapeutic and diagnostic) contact lens prototype is very promising to be commercially-available as materials needed for production are inexpensive and the device is minimally-invasive as it targets the crucial factors in preventing glaucoma progression: real-time monitoring and diligent drug administration.
Further studies on how human eyes will respond to these drug-releasing contact lenses are yet to be done.