If people with glaucoma don't stay on top of their condition, blindness may result. An experimental new contact lens is designed to help, by both monitoring glaucoma symptoms and automatically releasing medication as needed.
Glaucoma typically occurs when a blockage in the eye's drainage channels causes aqueous humor fluid to accumulate within the eye faster than it can drain out. This increases intraocular pressure (IOP) which may in turn damage the optic nerve, causing blindness.
Fortunately there are eye-drop medications that help reduce IOP, although they work best if the dosage is continuously modified based on the current amount of pressure in the eye. That's where the new contact lens comes in.
Created by scientists at South Korea's Pohang University of Science and Technology (POSTECH), the wirelessly powered device incorporates an IOP sensor made of hollow gold nanowires, along with a medication-filled drug delivery system and an integrated circuit chip. The latter monitors IOP levels via the sensor, and responds to any changes by triggering the delivery system to increase or decrease its dosage accordingly.
In tests performed on rabbits, the contact lens was found to be highly effective at managing the dosage of the glaucoma-treatment drug timolol, based on changes in the animals' IOP. The lens also exhibited "excellent chemical stability and biocompatibility." Additionally, the scientists believe that its feedback system could be incorporated into other types of wearables, for the management of other conditions.
A paper on the research, which was led by Prof. Sei Kwang Hahn and Dr. Tae Yeon Kim, was recently published in the journal Nature Communications. Hahn previously led the development of another type of contact lens, intended to prevent blindness in diabetics.
And while we have seen experimental timolol-releasing contact lenses before, most have been designed to gradually release the drug over time at a consistent rate – not at a varying rate, in response to changes in IOP.
Source: POSTECH
