In work that could improve diagnoses of many eye
diseases, MIT researchers have developed a new type of laser for
taking high-resolution, 3-D images of the retina, the part of the eye
that converts light to electrical signals that travel to the brain.
The research will be presented at the Conference on Lasers and
Electro-Optics and the Quantum Electronics and Laser Science
Conference in Baltimore on May 10.
The new imaging system is based on Optical Coherence Tomography
(OCT), which uses light to obtain high-resolution, cross-sectional
images of the eye to visualize subtle changes that occur in retinal
disease. OCT was developed in the early 1990s by MIT Professor James
Fujimoto, Eric Swanson at MIT Lincoln Laboratory and collaborators;
Fujimoto is an author of the report to be presented in May.
“Within the last few years optical coherence tomography has become a
standard diagnostic for ophthalmology. New techniques are now
enabling dramatic increases in image acquisition speeds. These
advances promise to enable new and powerful three-dimensional
visualization methods which could improve early diagnosis of disease
and treatment monitoring,” said Fujimoto, who holds appointments in
MIT’s Department of Electrical Engineering and Computer Science and
the Research Laboratory of Electronics.
Conventional OCT imaging typically yields a series of two-dimensional
cross-sectional images of the retina, which can be combined to form a
3-D image of its volume. The system works by scanning light back and
forth across the eye, measuring the echo time delay of reflected
light along micrometer-scale lines that, row by row, build up
high-resolution images.
Commercial OCT systems scan the eye at rates ranging from several
hundred to several thousand lines per second. But a typical patient
can only keep the eye still for about one second, limiting the amount
of three-dimensional data that can be acquired.
Now, using the new laser, researchers in Fujimoto’s group report
retinal scans at record speeds of up to 236,000 lines per second, a
factor of 10 improvement over current OCT technology.
Future clinical studies, as well as further development, may someday
enable ophthalmologists to routinely obtain three-dimensional “OCT
snapshots” of the eye, containing comprehensive volumetric
information about the microstructure of the retina. Such snapshots
could potentially improve diagnoses of retinal diseases such as
diabetic retinopathy, glaucoma and age-related macular degeneration.
Fujimoto’s colleagues on the work are Robert Huber, a visiting
scientist at MIT now at the Ludwig-Maximilians University in Germany,
Desmond C. Adler and Vivek Srinivasan. Adler and Srinivasan are both
graduate students in EECS.
The current research was sponsored by the National Science
Foundation, the National Institutes of Health and the Air Force
Office of Scientific Research.
mit.edu