Spectral Domain Optical Coherence Tomography ( SD-OCT)

Optical Coherence Tomography ( OCT) is a non-contact medical imaging technology similar to ultrasound and MRI. With OCT, reflected light is used to produce detailed cross-sectional and 3D images of the eye. An early version of this technology, time domain OCT ( TD-OCT) , uses a moving reference mirror for measuring the time it takes for light to be reflected. This relatively slow, mechanical process limits both the amount of data that can be captured as well as image quality. TD-OCT data is acquired at approximately 400 axial scans, or A-scans, per second. The newer Spectral ( or Fourier) Domain OCT ( SD-OCT) uses a significantly faster, non-mechanical technology. The SPECTRALIS® SD-OCT simultaneously measures multiple wavelengths of reflected light across a spectrum, hence the name spectral domain. The SPECTRALIS system is 100 times faster than TD-OCT and acquires 40, 000 A-scans per second. The increased speed and number of scans translates into higher resolution and a better chance of observing disease. The SPECTRALIS system is much more than just a faster next generation OCT. High speed image acquisition is combined with custom TruTrack™ technology to actively track the eye during imaging. Tracking eye movement with simultaneous dual-beam imaging minimizes motion artifact, enables noise reduction and allows the instrument to precisely track change over time. The result is point-to-point correlation between fundus and OCT scans, greater image detail and clarity, and more confident assessment of small changes. By integrating SD-OCT with confocal scanning laser ophthalmoscopy ( cSLO) , the SPECTRALIS platform has advanced the role of SD-OCT in ophthalmology. This combination of SPECTRALIS SD-OCT and cSLO fundus imaging reveals new details through multiple perspectives of the retina. These additional views are helping redefine diagnosis and treatment of many major eye diseases. SPECTRALIS SD-OCT offers TruTrack Active Eye Tracking which enables accurate and repeatable alignment of OCT and fundus images, Heidelberg Noise Reduction™ for fine image detail, AutoRescan™ for precise follow-up scan placement and multi-modality imaging that increases diagnostic power in an upgradable platform.