A new optical device about the size of a hand-held video camera, developed by researchers at the Massachusetts Institute of Technology, Cambridge, can scan a patient’s entire retina in seconds and could aid primary care physicians in early detection of many retinal diseases, including diabetic retinopathy, glaucoma, and macular degeneration.
Although other research groups and companies have created hand-held devices using similar technology, this new design is the first to combine cutting-edge technologies such as ultrahigh-speed 3D imaging, a tiny micro-electro-mechanical systems (MEMS) mirror for scanning, and a technique to correct for unintentional movement by the patient. These innovations, the authors say, should allow clinicians to collect comprehensive data with just one measurement.
To improve public access to eye care, the MIT group, in collaboration with the University of Erlangen and Praevium/Thorlabs, has developed a portable instrument that can be taken outside a specialist’s office, and used a primary-care physician's office, a pediatrician's office, or even in the developing world.
The instrument uses a technique called optical coherence tomography (OCT), sending beams of infrared light into the eye and onto the retina. Echoes of this light return to the instrument, which uses interferometry to measures changes in the time delay and magnitude of the returning light echoes, revealing the cross sectional tissue structure of the retina—similar to radar or ultrasound imaging.
The researchers were able to shrink what has been typically a large instrument into a portable size by using a MEMS mirror to scan the OCT imaging beam. They tested two designs, one of which is similar to a handheld video camera with a flat-screen display. In their tests, the researchers found that their device can acquire images comparable in quality to conventional table-top OCT instruments used by ophthalmologists.