Micron-resolution Optical Coherence Tomography of the Human Eye

We have developed a new technique for micron scale resolution cross-sectional imaging in biological systems called Optical Coherence Tomography (OCT)1,2 In OCT, low-coherence optical interferometry3,4 is used to resolve the position of reflective or optical backscattering sites within a sample. Two-dimensional tomographic images of a thin, optical slice of tissue may be obtained with 10 μm longitudinal and lateral resolution. Narrowband optical heterodyne detection achieves a sensitivity to reflected light as small as 10-10 of the incident optical power. OCT is non-contact, non-invasive, and has superior resolution to conventional clinical ultrasound. Unlike scanning laser ophthalmoscopy and scanning laser tomography, the optical sectioning capability of OCT is not restricted by the pupil-limited numerical aperture of the eye or ocular aberrations. OCT may be implemented in a compact, low-cost, fiber-optic based interferometer that is easily coupled to existing ophthalmic instrumentation. We demonstrate high-speed, in vivo OCT imaging in both the anterior and posterior eye.