Researchers develop eye-implantable sensor and smartphone tech for early Alzheimer's diagnosis

Korean researchers have developed a fluorescent sensor that can be inserted into the eye to diagnose Alzheimer's disease early and a smartphone-based monitoring technology.

A team of researchers, led by Professor Ji Yong-woo of the Department of Ophthalmology at Yongin Severance Hospital and Professor Haam Seung-joo of Yonsei University's Department of Chemical and Biomedical Engineering recently, said Friday that they have developed an eye-insertable intraocular lens fluorescent sensor for early diagnosis of Alzheimer's disease and a smartphone-based analysis technology for easy monitoring and verified its long-term bio-efficacy.

Alzheimer's disease is a condition in which specific proteins build up abnormally in the brain, causing a neuroinflammatory response and progressive cognitive impairment, including memory loss. The brain damage is irreversible, and the best treatment is early diagnosis and monitoring to slow its progression.

However, diagnosing Alzheimer's disease requires invasive tests, such as cerebrospinal fluid biopsies, and expensive equipment, including positron emission tomography (PET) and magnetic resonance imaging (MRI) machines, making repeated monitoring difficult.

The researchers, based on the high probability of detecting brain disease-related proteins in the eye, which is directly connected to the central nervous system, and the high use of intraocular lenses during cataract surgery in the elderly, where Alzheimer's disease is prevalent, developed a diagnostic platform that can easily monitor Alzheimer's disease using eye fluid and intraocular lenses.

The team also developed an image analysis technology that amplifies the fluorescence signal of the intraocular lens (IOL) sensor through smartphone coding. This technology makes the fluorescence signal value more than twice as clear as before, making it possible to monitor the disease visually.

The team also conducted various experiments to verify the sensing performance. For about four weeks, the fluorescence signal of the IOL sensor gradually increased for the target protein in an in vitro environment, like the aqueous humor in the eye. In addition, the pig eye test showed that the sensor worked in the living eye and secured long-term in vivo efficacy.

“The diagnostic sensor developed through this research is significant because it enables early diagnosis of Alzheimer's disease and long-term real-time visible monitoring in vivo,” Professor Ji said. “We will continue to commercialize the technology and expand it to other eye diseases, such as glaucoma and macular degeneration, and systemic diseases so that it can benefit real patients.”

The findings were recently published in Advanced Functional Materials, an international materials research and technology journal.