Smart contact lenses are capable of tracking tear glucose levels and delivering diabetes drug therapy directly to the retina.
The management of diabetes for many patients is a life-long commitment to mitigating risk. Whether patients accomplish this through careful dietary planning, a scheduled exercise routine, or glucose monitoring, consistency is key to success for all these strategies. Researchers and healthcare workers alike strive to improve the ease with which this consistency can be achieved. This general principle drives innovation, often creating new technologies to improve existing therapies or new treatment methods. An example of this is developing smart contact lenses using bioelectronics to create wearable devices capable of various tasks, including diagnosis, management, and treatment. Sensimed has already experienced great success using this model of combining the existing function of soft contact lenses with the added function of monitoring intraocular pressure in patients with glaucoma. The company received FDA approval for its product, Triggerfish, in March of 2016. Multi-billion-dollar companies like Google quickly identified the potential for generating real value with such products. Google is currently working in collaboration with the global healthcare company Novartis to create smart lenses to diagnose people with diabetes. However, rarely do such great endeavors come with few obstacles. Experts within Google and Novartis state that making such a device may not be feasible, as glucose measurements acquired solely from tears have been notoriously unreliable in past decades.
As of April 28, 2020, a research team at the Pohang University of Science and Technology (POSTECH) announced its development of a wireless smart contact lens designed to diagnose and treat diabetes. Just days prior, the group published their research in Science Advances outlining their findings and methodology. The study included several proof-of-concept steps, including real-time electrical detection of tear glucose concentrations, on-demand drug release using a flexible drug delivery system (f-DDS), and therapeutic efficacy of retinopathy agent of choice genistein, following ocular delivery. A calibrated ocular glucose sensor embedded in the smart contact lens measured glucose tear concentrations. Comparing these levels to blood glucose levels obtained by traditional glucometers is necessary to confirm the two are correlated. The study used five separate groups of non-diabetic and diabetic rabbit models to assess the in vivo treatment of diabetic retinopathy using smart contact lenses. The first four groups received the placebo, intravitreal injection of genistein, or intravitreal injection of Avastin in their left eye. The fifth group included all four groups where each subject received genistein delivered by the smart contact lens in the right eye. Imaging of retinal scarring highlighted by fluorescence dye measured therapeutic efficacy.
Results from the study found a consistent correlation between tear and blood glucose concentrations within rabbit models. Although previous findings have been highly controversial, researchers believe that tear glucose concentrations can be used reliably to diagnose and treat diabetes with proper calibration and baseline monitoring. In addition, rabbit models treated with genistein using the smart contact lens showed an increased reduction in retinal scaring compared to the placebo group (p < 0.05) and comparable retinal scaring with other treatment groups. Finally, the primary safety concern of using these smart devices is the risk of ocular burns caused by the device overheating. The study employed thermal infrared cameras to monitor for sudden increases in temperature with no adverse events reported.
The study offers initial evidence supporting a unique ocular drug delivery system as being relatively safe and effective. However, success hinges on bridging the gap in knowledge between tear and blood glucose concentrations. Further studies are needed to address whether the two are genuinely correlated. Still, offering a non-invasive method for tracking glucose levels could improve patient adherence and lead to better clinical outcomes.
- New smart contact lenses offer new solutions to diagnosing and treating chronic conditions like diabetes and glaucoma.
- The lenses rely heavily on using tear glucose levels for treatment. However, evidence surrounding tear glucose levels as an accurate indicator of blood glucose is controversial.
- The development of non-invasive, patient-friendly methods for glucose monitoring could result in real clinical benefits such as improved glucose control and fewer microvascular complications.
Keum, Do Hee, et al. “Wireless Smart Contact Lens for Diabetic Diagnosis and Therapy.” Science Advances, vol. 6, no. 17, 2020,
Stephen Rubano, PharmD. Candidate, USF Taneja College of Pharmacy