New Glaucoma Test Allows Earlier, More Accurate Detection

 

Cumbersome Glaucoma tests that require a visit to the ophthalmologist   could soon be history thanks to a home test developed by a UA engineer.

 

 

 

Phoenix   ophthalmologist Dr. Gholan Peyman demonstrates a prototype Glaucoma test   instrument that's noninvasive and simpler to use than current   procedures. It can also be used in situations that are difficult or   impossible with current tests. (Credit: Image courtesy of University of   Arizona College of Engineering)

The self-test instrument has been designed in Eniko Enikov's lab at   the UA College of Engineering. Gone are the eye drops and need for a   sterilized sensor. In their place is an easy-to-use probe that gently   rubs the eyelid and can be used at home.

  "You simply close your eye and rub the eyelid like you might casually   rub your eye," said Enikov, a professor of aerospace and mechanical   engineering. "The instrument detects the stiffness and, therefore,   infers the intraocular pressure." Enikov also heads the Advanced Micro   and Nanosystems Laboratory.

  While the probe is simple to use, the technology behind it is   complex, involving a system of micro-force sensors, specially designed   microchips, and math-based procedures programmed into its memory.

  Enikov began working on the probe four years ago in collaboration   with Dr. Gholan Peyman, a Phoenix ophthalmologist. "We went through   several years of refinement and modifications to arrive at the current   design," Enikov noted.

  The National Science Foundation has funded the work, and Enikov and   Peyman now are seeking investors to help fund final development and   commercialization of the product.

  In addition to screening for Glaucoma, an eye disease that can lead   to blindness if left untreated, the device corrects some problems with   the current procedure, and can be used to measure drainage of   intraocular fluid.

  "Eye pressure varies over a 24-hour cycle," Enikov said. "So it could   be low at the doctor's office and three hours later it might be high.   With only a single test, the doctor might miss the problem. Having the   ability to take more frequent tests can lead to earlier detection in   some cases."

  Once the diagnosis is made, several treatments are available. The   question then is: How effective are they? Patients could use the probe   at home to trace how much the pressure decreases after using eye drop   medications, for instance.

  "One of the reasons pressure builds up in the eye is because fluid   doesn't drain properly," Enikov noted. "Currently, there are no methods   available to test drainage."

  Current tests require applying pressure directly to the cornea, but   only very light pressure is safe to use, and it doesn't cause the fluid   to drain.

  "Our technique allows us to apply slightly greater pressure, but it's   still not uncomfortable," he said. "It's equivalent to rubbing your eye   for a brief period to find out if the pressure changes. If it does, we   know by how much and if there is a proper outflow of intraocular fluid."

  Sometimes, a surgical shunt is used to help fluid drain from the eye.   "The problem with Glaucoma shunts is they can plug up over time,"   Enikov noted. "Or if they're not properly installed, they may drain too   quickly. So you would want to know how well the shunt is working and if   it is properly installed. Our device could help answer those questions."

  In another scenario, certain patients cannot be tested for Glaucoma   using currently available procedures. "If a patient had cataract surgery   or some other surgery through the cornea, the cornea sometimes   thickens," Enikov said. "The cornea's structure is different, but our   test remains accurate because it's not applied to the cornea."

  Instead, it presses the entire eyeball, much as you might press a balloon to determine its stiffness.

  "The innovation with our device is that it's noninvasive, simpler to   use and applies to a variety of situations that are either difficult to   address or impossible to test using the current procedures," Enikov   said. "That's why we're so excited about this probe. It has great   potential to improve medical care, and significant commercial   possibilities, as well."

  http://www.sciencedaily.com/releases/2011/01/110104101331.htm

 

    The above story is reprinted from materials provided by University of Arizona College of Engineering. The original article was written by Ed Stiles.

    Note: Materials may be edited for content and length. For further information, please contact the source cited above.