Scientists design smart contact lenses to fight condition that causes blindness
Eye clinical officer Hezron Waswa examines a patient's eyes in Mombasa.
What you need to know:
- Researchers in China developed a smart contact lens for treating the disease.
- The device aims to sense rising fluid pressures within the eye and automatically delivers medication whenever needed.
The device aims to sense rising fluid pressures within the eye and automatically delivers medication whenever needed.
The experts came up with the theranostic device, which combines diagnostics and therapeutics, after scientists from Sun Yat-Sen University in Guangzhou tested the wireless, double-layer contact lens on the eyes of pigs and live rabbits and found that it could measure intraocular pressure using small, sandwich-like sensors that produce an electrical signal when squeezed together, according to Nature, a global scientific peer reviewed journal.
Besides controlled ocular drug deliveries mediated via contact lens devices, experts have employed versatile strategies including thermal-responsive, enzyme triggering, and hydrogel layer-controlled drug.
According to the experts, when that signal becomes strong enough, it can directly trigger the delivery of an anti-glaucoma drug such as brimonidine, which is kept in a hydrogel layer within the lens and delivered into the cornea with the assistance of a weak electrical current.
They further explain that this design would allow for a soft, minimally invasive and battery-free contact lens, and one that could be mass-produced, with a relatively simple manufacturing process similar to the commercial production of printed circuit boards.
The researchers are still conducting trials.
In Kenya it is estimated that 4.3 per cent of persons aged above 50 years have the glaucoma disease. The blindness caused by glaucoma is irreversible, according to the country’s 2020 National Guidelines for Management of Glaucoma.
“We know that if diagnosed early, and with quality care, blindness due to glaucoma can be prevented. It is chronic and progressive and usually has no symptoms until at advanced stages when considerable loss of vision has occurred and disproportionately affects the black race.”
Experts highlight that Africa has a high prevalence of glaucoma, with the commonest type being primary open angle glaucoma (POAG).
“A population-based study in Nakuru found the prevalence of glaucoma to be 4.3 per cent in people aged 50 years and above. The risk factors for POAG include African race, older age, high intraocular pressure, family history of glaucoma, type 2 diabetes mellitus, high myopia, and thin central corneal thickness,” the Ministry of Health cites.
The government points out that the disease has no known cure.
“Successful management of glaucoma requires early diagnosis followed by lifelong monitoring and appropriate treatment and although there is no known cure for glaucoma, these strategies can prevent sight loss.”
“In Kenya, as in other countries in sub-Sahara Africa, the prevention of blindness from glaucoma faces several challenges: low levels of awareness of glaucoma, late presentation, low coverage and affordability of glaucoma treatments, poor adherence to treatment approaches and erratic follow-up,” the government says.
The World Health Organization notes that globally, at least 2.2 billion people have a near or distance vision impairment.
“In at least one billion – or almost half – of these cases, vision impairment could have been prevented or has yet to be addressed,” says WHO..
This one billion people includes those with moderate or severe distance vision impairment or blindness due to unaddressed refractive error (88.4 million), cataract (94 million), glaucoma (7.7 million), corneal opacities (4.2 million), diabetic retinopathy (3.9 million), and trachoma (2 million), as well as near vision impairment caused by unaddressed presbyopia (826 million).
