A new optical tool allows the detection of blinding eye disease very easy and efficient.
The device — approximately the size of a hand-held video camera — scans a patient’s full retina in seconds and could assist primary care doctors in the timely detection of a suite of retinal conditions including diabetic retinopathy, glaucoma and macular degeneration.
Normally, to diagnose retinal diseases, an ophthalmologist or optometrist must examine the patient in his or her office, typically with table-top instruments. However, few people visit these specialists regularly. 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.
“Hand-held instruments can enable screening a wider population outside the traditional points of care,” said researcher James Fujimoto of MIT, an author on the Biomedical Optics Express paper. For instance, they can be used at a primary-care physician’s office, a pediatrician’s office or even in the developing world.
How it Works
The instrument uses a technique called optical coherence tomography (OCT), which the MIT group and collaborators helped pioneer in the early 1990s. The technology sends 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. Tabletop OCT imagers have become a standard of care in ophthalmology, and current generation hand-held scanners are used for imaging infants and monitoring retinal surgery.
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.
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