Using Nanotechnology to Treat Glaucoma
David Barth traces his love of nanotechnology back to the eighth grade, when his chemist father attended a conference and returned with wafers imprinted with photolithography. "I was very impressed with that, and that is when I started being interested," David says. He chose to study Mechanical Engineering at Stevens and immediately immersed himself in nanotechnology, eventually seeking a Master's Degree in Mechanical Engineering, with a concentration in Nanotechnology through Stevens Nanotechnology Graduate Program.
His work as an undergraduate student came to a climax with a highly-impressive microtechnology Senior Design project, a glaucoma treatment device created by a multidisciplinary team advised by Associate Professor of Mechanical Engineering Dr. Eui-Hyeok (EH) Yang. The team created a biomedical implant for intraocular pressure relief that uses a novel method to sidestep the problems associated with traditional glaucoma treatment.
A group of eye conditions that cause damage to the optic nerve, leading to blindness, Glaucoma is the second-most common cause of blindness in the United States and worldwide. In many cases, damage to the optic nerve is a result of high intraocular pressure (IOP) caused by a buildup of fluid within the anterior chamber of the eye – between the colored part and the outer cornea. This pressure builds and pinches the optic nerve, progressively diminishing sight at the edge of vision until complete blindness occurs. Treatments for glaucoma attempt to lower intraocular pressure to a normal level.
Though drug and surgical treatments for high intraocular pressure exist, there are problems associated with each. Patients may be remiss in taking pharmacological solutions such as pills and eye drops. Surgical implants, which have been around since the 1960s, fail after a few years due to design flaws.
The Stevens team sought an innovative design that would allow fluid to drain from the eye at a particular rate, without relying on growing tissue to mitigate the flow. Their solution is a Microelectromechanical systems (MEMS) microchannel – a long serpentine canal a mere 100 microns wide, that winds along a plate. Fluid from the eye flows through a channel about the width of a human hair. The width and length of the channel effectively regulates drainage through friction, leaving a healthy pressure in the eye.
"Rather than having a huge outflow that we have to restrict, we regulate the flow from beginning to end so that the amount to come out is exactly the amount we want," David explains. "It's a consistent design. Unlike current treatments, it won't change how it operates over time."
"I think it does have potential, and I think it does have clear advantages over some of the devices that are out there," he adds.
David generated the initial idea for an intraocular relief device in a Micro/Nano Electro-Mechanical Systems (NEMS/MEMS) class, in which Dr. Yang challenged students to devise a novel MEMS device that could be modeled, simulated, and tested with modeling software. "It was a big struggle to come up with an idea, but when I did come up with something, it was a very similar sort of idea," David says. He pursued the idea through the Stevens Summer Scholars program, and continued to work on it with a team of Mechanical Engineering, Physics, and Mathematics students.
"This is the first Senior Design project which truly demonstrates the MEMS technology," says Professor Yang, who has 15 years of extensive experience in MEMS technology. "David was one of the students enrolled in the Introduction to BioMEMS course that I taught, from which he came up with an initial MEMS-based microvalve idea that led to his summer project in 2010 under the Stevens Scholars Program. The research concept was eventually developed toward the current Senior Design project. It is important to note that this project is the first undergraduate student project that fully utilizes our Micro Device Laboratory (MDL) facilities! The team has made great strides in demonstrating the MEMS microchannel-based Intra Ocular Pressure regulator."
The boyhood infatuation with nanotechnology, bolstered by his Stevens education, has not ceased. He will pursue his Ph.D. in nanotechnology at University of California, Berkeley. David attributes his success to Stevens strong program, which allows undergraduates to pursue their Master's degrees simultaneously. "Doing the master's program allowed me to focus on nanotechnology, and gave me direction as to what to pursue for a doctoral degree."