Glaucoma detection: There's a lens for that
November 18, 2013
According to the World Health Organization, glaucoma is the second-leading cause of blindness in the world. Although the disease is somewhat of a mystery to doctors, it is believed that glaucoma develops due to raised pressure in the eye until, at a certain point, it branches off into a cluster of conditions that slowly lead to blindness over time. It's a silent assailant, often going undiscovered for long periods of time, as symptoms can be subtle and hard to spot. Patients who suffer from open-angle glaucoma, the most common form of the ailment, often experience the effects of the disease with virtually no pain or pressure. Because of this, the Glaucoma Research Foundation estimates that an estimated 2.2 million Americans have glaucoma yet only about half know it. However, new developments in contact lens technology could lead to a major breakthrough in the identification and treatment of this troublesome eye condition.
A problematic condition for doctors
For years, the study and treatment of glaucoma has been an uphill battle, but why? According to James Brandt, a professor of ophthalmology at UC Davis, glaucoma has proved difficult to monitor due to its location in the eye.
"It's very different from situations like cardiac disease or diabetes, where patients can wear devices that measure heart rate or blood pressure 24 hours a day for a week or more to get a better idea of what's going on," Brandt said to IO9, an online publication covering the future of science. "We don't have that for glaucoma, and that's one of the biggest clinical frustrations we have."
Until recently, the only source for diagnosis and treatment has been the study of snapshots taken during routine doctor visits. As MIT Technology Review noted, this method has provided doctors with very little insight into the disease since glaucoma symptoms can change drastically from one hour to the next.
Glaucoma-monitoring contact lenses
Fortunately, modern medicine has begun to provide some high-tech solutions for glaucoma patients who may be running out of time. One of the latest breakthroughs in glaucoma research comes in the form of a contact lens that monitors glaucoma symptoms around the clock. Tingrui Pan and Hailin Cong, researchers at UC Davis, designed one of the first prototypes of the lens, with plans for another model that can dispense medication directly to the eye as well. The lens takes a two-pronged approach to glaucoma symptom identification and monitoring. First, it measures intraocular pressure, which is the main cause of glaucoma and its symptoms. Secondly, the lenses are outfitted with a means for correspondence, and the ability to send the collected data to a computer for processing.
In the meantime, a similar product has been developed by Swiss company Sensimed. Its "Triggerfish" contact lens system works similarly to the UC Davis model, with the ability to wirelessly transmit collected data to a receiver worn around the patient's neck. The Triggerfish lens is made of the same material as normal contact lenses, then embedded with a microprocessor and strain gauge that can detect fluid accumulation in the eye.
New hope for glaucoma patients
The new technology provides a new weapon in the study, treatment and prevention of glaucoma. Doctors now have the opportunity to track changes in glaucoma symptoms at any hour of the day or night. Kaweh Mansouri, an ophthalmologist at University Hospital in Geneva, uses the Sensimed system to study intraocular pressure changes and tailor medication regimens to his patients. "For the first time, we were able to look into the darkness of glaucoma, and we saw things happening during the night that were surprising," said Mansouri to MIT Technology Review. In an interview with MedGadget earlier this year, Sensimed's Chief Medical Officer, Dr. René Goedkoop, revealed that the Triggerfish lens is still in a restricted commercial stage, but believes it should be more widely available in 2014.
"Contact Lenses of the Future Will Treat Your Eye Diseases," IO9, Aug. 7, 2008, http://io9.com/5034439/contact-lenses-of-the-future-will-treat-your-eye-diseases
"Glaucoma Facts and Stats," Glaucoma Research Foundation, April 22, 2013, http://www.glaucoma.org/glaucoma/glaucoma-facts-and-stats.php
"Glaucoma is second leading cause of blindness globally," World Health Organization, Nov. 4, 2004, http://www.who.int/bulletin/volumes/82/11/feature1104/en/
"Glaucoma Test in a Contact Lens," MIT Technology Review, March 31, 2010, http://www.technologyreview.com/news/418247/glaucoma-test-in-a-contact-lens/
"Sensor-Equipped Contact Lens Monitors Glaucoma Symptoms Around the Clock," Popular Science, March 31, 2010, http://www.popsci.com/science/article/2010-03/sensor-equipped-contact-lens-monitors-glaucoma-symptoms-around-clock
"Smart, Continuous Monitoring of Intra-Ocular Pressure with Triggerfish Contact Lens: Q&A with René Goedkoop, CMO of Sensimed," MedGadget, July 29, 2013, http://www.medgadget.com/2013/07/smart-continuous-monitoring-of-the-intra-ocular-pressure-with-the-triggerfish-contact-lens-qa-with-rene-goedkoop-cmo-of-sensimed.html