With an increase in the average age of the global population over the last several decades, glaucoma has become an important global health concern that claims the eyesight of many patients annually [1]. Glaucoma-induced neuron damage is irreversible, which means that early detection is necessary since patients are often not aware of vision loss until a very advanced stage of the disease [3]. One risk factor that is often indicative of glaucoma is an increase in a patient’s intraocular pressure (IOP) [2]. IOP is determined by the inflow and outflow of aqueous humor to the eye, which is subject to change throughout the day as a person moves; in fact, fluid flow can be 50% lower during sleeping hours [2]. Such large variations mean that it is not possible for a singular pressure measurement taken at one time of the day to embody the entirety of a patient’s unique IOP trends that could signify glaucoma development. Therefore, there is a need for continuous IOP monitoring for early detection of glaucoma.

Previously we had developed a soft contact lens sensor for IOP measurement using microfluidic sensing techniques [4]. This proposal aims to further that work by adding new feature designs to the lens to modify the local strength of the lens. Under IOP changes, the new added features will be deformed accordingly. Through the calibration of the features size and shape change, IOP will be determined. First, a finite element model will be developed in COMSOL with varying applied pressure between 10 and 35 mmHg. The maximum deformation of the designed features on the lens will be used to optimize the design, including feature location, size etc. Experimental testing will be conducted using porcine eyes. The performance of the new wearable sensor will be evaluated. This analysis will further the research of wearable lenses for intraocular pressure measurement to detect early onset glaucoma.

References

[1] S. Kingman, "Glaucoma is second leading cause of blindness globally," Bulletin of the World Health Organization, vol. 82, no. 11, pp. 887-888, Novemebr 2004.

[2] D. Križaj, H. Kolb, E. Fernandez and R. Nelson, "What is glaucoma?," in Webvision: The Organization of the Retina and Visual System, Salt Lake City, 2019.

[3] D. A. Lee and E. J. Higginbotham, "Glaucoma and its treatment: A review," American Journal of Health-System Pharmacy, vol. 62, no. 7, pp. 691-699, 2005.

[4] Campigotto, A., Leahy, S., Zhao, G., Campbell, R. J., & Lai, Y. (2019). Non-invasive intraocular pressure monitoring with contact lens. British Journal of Ophthalmology, https://doi.org/10.1136/bjophthalmol-2018-313714