Development Of Smart Intraocular Lens Integrated With Biosensors For Early Diagnosis Of Alzheimer’S Disease

The integration of biochip technology with ocular biomarkers represents a promising direction in translational biomedical engineering for neurodegenerative disease detection. Alzheimer’s disease (AD) is often diagnosed after significant cognitive decline due to reliance on invasive and costly diagnostic tools. Because the eye shares structural and vascular connections with the brain, aqueous humor may reflect molecular changes associated with neurodegeneration. We aimed to develop a smart intraocular lens (IOL), implanted during routine cataract surgery, integrating biosensing technology for real-time detection of AD-related biomarkers in aqueous humor.

This translational ophthalmic and biomedical engineering study was conducted at a tertiary academic medical center in collaboration with proteomics and bioengineering laboratories. The project integrated aqueous humor biomarker discovery, biochip-based sensor design, and preclinical validation using a rabbit cataract surgery model with intraocular lens implantation.

Aqueous humor samples underwent liquid chromatography–tandem mass spectrometry proteomic profiling to identify candidate AD biomarkers, followed by parallel reaction monitoring validation. A protein-responsive hydrogel biosensor incorporating biochip technology was integrated into an IOL platform. Moiré pattern–based optical signal amplification enhanced detection sensitivity. Smart IOLs were implanted in rabbit cataract models. Defined concentrations of candidate biomarkers were injected into the anterior chamber, and signal responses were quantified using custom moiré microscopy with frequency-domain signal analysis

Proteomic analysis demonstrated distinct clustering of AD aqueous humor protein profiles compared with controls and other neurological diseases. Validation confirmed increased acetylcholinesterase (AChE) and secreted phosphoprotein-1 (SPP1) levels in AD samples. In vivo testing showed that injection of candidate biomarkers induced hydrogel contraction within the sensor micrograting, generating measurable moiré pitch shifts. Following SPP1 (100 nM, 200 μL) 2nd injection, signal intensity increased from 68.83μm to 99.70μm, representing a 44.8% increase within 20 minutes. Sequential injections demonstrated reproducible and dose-responsive signal amplification. No inflammation, infection, or anterior segment complications were observed.

This smart IOL functions beyond traditional visual correction by integrating biochip-based biosensors that analyze ocular biofluids for disease-specific biomarkers. By leveraging liquid biopsy principles within aqueous humor, the device enables minimally invasive, continuous monitoring directly inside the eye. In this preclinical model, real-time biomarker detection and maintained biocompatibility were demonstrated. This approach highlights the convergence of nanoengineering and biotechnology in ocular diagnostics and may contribute to earlier detection and proactive management of Alzheimer’s disease.