Optical Coherence Tomography (OCT) is a fundamentally new type of optical imaging modality. OCT performs high-resolution, cross-sectional tomographic imaging of the internal microstructure in materials and biologic systems by measuring backscattered or back reflected light. OCT images are two-dimensional data sets which represent the optical backscattering in a cross-sectional plane through the tissue. Image resolutions of 1 to 15 µm can be achieved one to two orders of magnitude higher than conventional ultrasound. Imaging on the OCT can be performed in situ and in real time. The unique features of this technology enable a broad range of research and clinical applications.

OCT, imaging the internal cross-sectional microstructure of tissues using measurements of optical backscattering or back reflection, was first demonstrated in the early nineties. OCT imaging was performed in vitro in the human retina and in atherosclerotic plaque as examples of imaging in transparent, weakly scattering media and nontransparent, highly scattering media. OCT was initially applied for imaging in the eye and, to date; OCT has had the largest clinical impact in ophthalmology. The first in vivo tomograms of the human optic disc and macula were demonstrated in 1993. OCT enables the noncontact, noninvasive imaging of the anterior eye as well as imaging of morphologic features of the human retina including the fovea and optic disc. The technology was transferred to industry and introduced commercially for ophthalmic diagnosis, and is now available from numerous manufacturers, with specific models listed below.

• Zeiss Cirrus HD-OCT 5000
• Zeiss Cirrus HD-OCT 500
• Zeiss Cirrus Photo 800
• Zeiss Cirrus Photo 600
• Zeiss Cirrus HD-OCT 4000
• Zeiss Cirrus HD-OCT 400
• Zeiss Stratus OCT 3
• Optovue Avanti RTVue XR
• Optovue RTVue Premier
• Optovue iFusion
• Optovue iVue
• Heidelberg Spectralis OCT
• Heidelberg Spectralis OCT Plus
• Heidelberg Spectralis FA + OCT
• Heidelberg Spectralis HRA + OCT
• Topcon 3D OCT-2000
• Topcon 3D OCT-1000