Smart Contact Lens to Treat Glaucoma

A flexible contact lens that senses eye pressure and releases a drug on-demand could help treat glaucoma, the second leading global cause of blindness worldwide. The compact wireless device, which has been developed by a team of Chinese researchers and tested in pig and rabbit eyes so far, appears to detect and reduce rising eye pressure, one of the usual causes of glaucoma.

Glaucoma is an umbrella term for a group of eye diseases where damage to the optic nerve, which relays visual information to the brain, causes irreversible vision loss and blindness in millions of people worldwide. Where this new research makes ground is in developing a device capable of detecting changes in eye pressure and delivering therapeutic drugs as needed. Recent efforts to develop smart contact lenses as wearable devices for treating eye conditions have either focused on sensing pressure changes in the eye or delivering a drug – but not both – and glaucoma treatment usually involves eye drops, laser therapy, or surgery to reduce eye pressure. While it sounds exciting, keep in mind that as scientists continue experimenting with all sorts of nifty devices for treating eye diseases, early detection of glaucoma and timely treatment remains vital.

Once detected, therapy for glaucoma can arrest or slow its deterioration in the majority of cases,” Jaimie Steinmetz, a research scientist at the Washington-based Institute for Health Metrics and Evaluation, and collaborators wrote in 2020 when analyzing the global burden of eye diseases, including glaucoma. But glaucoma is typically hard to catch because peripheral vision is the first to go, and devices used to diagnose the condition only provide snapshot measurements of intraocular pressure, which fluctuates with activity and sleep-wake cycles.

Hence the importance of improving systems of surveillance, highlighting risk among family members of cases, and effectiveness of care once treatment is initiated,” Steinmetz and co-authors stressThat said, contact lenses which sit snug against the eye hold great appeal for delivering therapies for eye conditions. But incorporating electrical circuits and sensors into small, flexible, curved, and ultra-thin contact lenses presents a serious engineering challenge. For something like this to work, it needs to be sensitive enough to detect pressure changes and release precise amounts of drug on demand – all without blocking vision and irritating the eye. “It is highly challenging to install an intricate theranostic system composited by multi-modules on a contact lens,” electrical engineer Cheng Yang of Sun Yat-Sen University and colleagues write in their paper.

Eye Scan Predicts Mortality Risk

Using deep learning to predictretinal age” from images of the internal surface of the back of the eye, an international team of scientists has found that the difference between the biological age of an individual’s retina and that person’s real, chronological age, is linked to their risk of death. This ‘retinal age gap’ could be used as a screening tool, the investigators suggest.

Reporting on development of their deep learning model and research results in the British Journal of Ophthalmology, first author Zhuoting Zhu, PhD, at Guangdong Academy of Medical Sciences, together with colleagues at the Centre for Eye Research Australia, Sun Yat-Sen University, and colleagues in China, Australia, and Germany, concluded that in combination with previous research, their study results add weight to the hypothesis that “… the retina plays an important role in the aging process and is sensitive to the cumulative damages of aging which increase the mortality risk.”

Estimates suggest that the global population aged 60 years and over will reach 2.1 billion in 2050, the authors noted.

Aging populations place tremendous pressure on healthcare systems.

But while the risks of illness and death increase with age, these risks vary considerably between different people of the same age, implying that ‘biological aging’ is unique to the individual and may be a better indicator of current and future health. As the authors pointed out, “Chronological age is a major risk factor for frailty, age-related morbidity and mortality. However, there is great variability in health outcomes among individuals with the same chronological age, implying that the rate of aging at an individual level is heterogeneous. Biological age rather than chronological age can better represent health status and the aging process.

Several tissue, cell, chemical, and imaging-based indicators have been developed to pick up biological aging that is out of step with chronological aging. But these techniques are fraught with ethical/privacy issues as well as often being invasive, expensive, and time consuming, the researchers noted.