The recent Diabetes Control and Complications Trial has clearly demonstrated that glycemic control in patients with diabetes mellitus is crucial. A critical component of intensive diabetes management is accurate and frequent glucose monitoring. However, the current generation of home glucose meters is only accurate to +/- 15 percent, requires a fingerstick for blood sampling, and must be carried as a separate kit everywhere with the patient. The present invasive methodologies show poor patient compliance which translates to negative health consequences for a significant proportion of patients with diabetes mellitus. We will develop a novel, real-time glucose sensor which is minimally invasive (or even by some definitions noninvasive) which will be contained within an outer ridge of a contact lens, or placed within an ocular insert underneath the eyelid. These devices will sense the glucose level in the tear fluid, which has been shown to track the glucose level in blood. The sensing material utilizes a novel polymerized colloidal array (PCCA) material which contains a recognition agent for glucose. The PCCA contains a cubic array of colloidal particles polymerized in a hydrogel. This PCCA diffracts light of a wavelength determined by the array spacing. Exposure to glucose changes the hydrogel volume which results in a change in the array spacing. This alters the diffracted wavelength. The patients will determine their glucose concentrations by looking at their contact lenses in a mirror; the colors observed will accurately give their glucose concentrations. The work here in this Phase I program will demonstrate proof of concept for this sensor by demonstrating that the glucose sensing PCCA will properly function at the tear fluid glucose concentrations and will not be confounded by other species present in the tear fluid.
