A new optical device puts the power to detect eye disease in the palm of a hand. The tool -- about the size of a hand-held video camera -- scans a patient's entire retina（视网膜） in seconds and could aid primary care physicians in the early detection of a host of retinal diseases including diabetic retinopathy, glaucoma（青光眼） and macular degeneration. Researchers at the Massachusetts Institute of Technology (MIT) describe their new ophthalmic-screening instrument in a paper published today in the open-access journal Biomedical Optics Express, published by The Optical Society (OSA). Although other research groups and companies have created hand-held devices using similar technology, the new design is the first to combine cutting-edge technologies such as ultrahigh-speed 3-D 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.

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.