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Contact lenses may soon dispense drugs, monitor glucose
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Contact lenses that elute drugs and those that measure glucose may be available in the near future if technologies being developed by OcuMedic Inc. and i-Chek prove successful.
Researchers from Rowan University developed drug-eluting technology in a silicone hydrogel contact lens for OcuMedic, and researchers from the University of Maryland developed a glucose monitoring contact lens that uses a mobile device to store tear glucose readings for i-Chek
Keith Ignotz, OcuMedic CEO and i-Chek advisor, discussed with Primary Care Optometry News why 50 years of previous technologies have failed and how these companies plan to succeed.
PCON: Other companies have attempted sustained drug release in a contact lens. What is OcuMedic doing differently?
Ignotz: OcuMedic’s technology was developed by Mark Byrne, PhD, distinguished professor of chemical and biomedical engineering and the founding head of the Biomedical Engineering Department at Rowan University, and his research team. Dr. Byrne serves as cofounder of OcuMedic and chief technical officer. The technology rests on nine issued patents, and efficacy has been proven in an animal model.
This novel therapeutic contact lens, made of silicone hydrogel, has a memory capable of controlled release of first-line ophthalmic agents, both inflammatory and antibiotic. It is also a platform that has been tested for a wide range of other drugs as well as molecules to enhance lens comfort and treat dry eye.
Controlled-release contact lenses have been the subject of discussion and investigation for 50 years. Previous methods suffer from either poor control of the release profile or inadequate drug loading, with most researchers demonstrating both problems. Thus, there are no products on the market today.
With the OcuMedic method, memory for the drug is produced during polymer synthesis, where monomers are complexed noncovalently to the drug and crosslinked into a hydrogel matrix. Upon removal of the drug, macromolecular memory sites remain within the hydrogel with affinity for the drug. The drug’s heightened interaction with these memory pockets enhances its loading and slows its transport within the hydrogel despite comparable free volume of drug transport.
It has been shown that the extension of release has a strong dependence on mimicking biological recognition in the design, exploiting the chemical diversity and amounts of monomers in relation to the drug. Thus, OcuMedic can literally dial in the release of drug from the lens over time, delivering a therapeutic concentration of drug payload for the duration of wear.
PCON: How does the i-Chek technology work?
Ignotz: The i-Chek technology measures the glucose in tears noninvasively as a person wears a contact lens with or corneal bandage without visual correction.
The proprietary technology was developed by Joseph R. Lakowitz, PhD, director of the Center for Fluorescence Spectroscopy at the University of Maryland. There are two granted patents and two patent applications based on the recent enabling discovery. Eighty percent of today’s contact lenses are based on silicone hydrogel polymers. Dr. Lakowitz’s lab discovered how to bind an amphipathic polymer, a molecule containing both polar (water-soluble) and nonpolar (non water-soluble portions in its structure), forming glucose-sensitive fluorophores. In vitro testing suggests that the i-Chek glucose sensing polymer is durable, as it will not wash out, and reversible, as the tear glucose concentrations change during wear.
An eye safe light is shined on the lens for a few seconds, and a fluorescence signal that measures the glucose concentration is received by a small detector next to the light source. The electronics for the emitter and detector will be configured into a compact package, allowing the detector to attach to the end of a mobile phone. The phone or other mobile device will display and store the tear glucose reading for the patient or store readings over time that can be sent to the physician.
PCON: What are some advantages of a glucose monitoring contact lens?
Ignotz: The advantages to the i-Chek technology are numerous. Noninvasive measurement eliminates the pain and inconvenience of finger sticks and provides infection control, so patient compliance will increase. Real-time data can contribute to better glucose control. Because the technology is quick and noninvasive the patient can repeat the measurement over a short time to determine if they are experiencing a rapid rise or fall in glucose that could cause them to pass out and it provides trend data to help them better gauge how much insulin to take. Currently, patients only test themselves once, if at all, each day and do not have this type of trend information with the current technology.
PCON: What kind of impact will this have on those with diabetes?
Ignotz: A dramatic one. According to the CDC, diabetes in the U.S. and internationally is at epidemic levels. U.S. prevalence in 2015 was 30.3 million Americans, or 9.4% of the population, costing $245 billion/year in total for the U.S. health care system. A quick, noninvasive glucose testing technology will eliminate the pain, cost and inconvenience of the current testing method, which can lead to uncontrolled glucose and the underlying cause of costly complications such as cardiovascular disease, neuropathy, nephropathy, retinopathy, foot damage, skin conditions, hearing impairment and Alzheimer’s disease.
PCON: What impact will these two products have on optometrists and their treatment protocols?
Ignotz: Currently, eye drops wash out quickly, with only about 5% of the drug getting to the desired site. Most therapeutic eye drop regimens require multiple drops per day, and most patients miss doses. The OcuMedic solution is continuous dosing, providing more efficacious and convenient therapy, decreasing complications and reducing health care costs.
Optometrists who are licensed to dispense diagnostic and therapeutic agents are ideally suited to deliver the OcuMedic therapy as the prevailing contact lens fitter. OcuMedic’s technology will provide clinicians a powerful new tool to treat patients.
Optometry is also ideally suited to deliver the i-Chek glucose monitoring contact lens as part of the comanagement of the patient with diabetes. The endocrinologist manages the patient’s metabolic condition, yet the patient is required to have an annual or bi-annual dilated eye exam, most frequently performed by an optometrist. This is where the glucose monitoring contact lens could be dispensed.
PCON: Can you comment on a timeline for the development of these products? When can we expect human clinical trials?
Ignotz: OcuMedic plans to complete the preclinical efficacy and safety studies in 18 months and then commence the phase 1/2 human clinical trials. The i-Chek technology will be safety tested in New Zealand white rabbits for 12 months, followed by an 8- to 12-subject human trial to demonstrate further safety and efficacy. – Interviewed by Abigail Sutton
Disclosure: Ignotz serves as CEO and president of OcuMedic Inc. and an advisor to i-Chek, with a financial interest in i-Chek.