Stratus OCT has impressive spatial resolution (10 microns), with additional differentiation possible in transparent tissues.
Analogous to a sort of "optical ultrasound" the technology has been documented as capable of imaging single cells in living systems via a surface, intravascular or endoscopic approach. Stratus OCT has a smaller footprint, can scan four times faster, and store 10 times the data than previous models.
Stratus OCT has a normative database containing agematched reference values for retinal nerve fiber layer thickness (NFL) that aids in identifying NFL defects secondary to glaucoma and other neuropathies, as well as an analysis change package that gives one the ability to compare the data from left and right eyes from successive visits and over time.
Radial line scans through the optic disc provide cross-sectional information regarding cupping and neuroretinal rim area. Unlike other instruments, the optic disc margin is objectively determined by the interpretation of the signals received from the end of the retinal pigment epithelium in the retina.
Stratus OCT also provides a volumetric and area assessment in tabular format. Stratus OCT has demonstrated reliability and consistency in its determination of NFL thickness in both normal and glaucomatous subjects. A study by Guedes and coworkers, which included 534 eyes in 367 subjects (166 eyes of normal subjects, 83 eyes of glaucoma suspects, 196 eyes of early glaucoma patients and 89 eyes of advanced glaucoma patients), determined the presence of a correlation between the macular and NFL thickness measurements, concluding that OCT has usefulness in the clinical assessment of glaucoma.
Unstundag and researchers and Wirbelauer and associates have used the instrument to examine the use of optical coherence tomography for the purpose of evaluating anatomical changes in the anterior segment. Unstungad's team used OCT after laser in situ keratomileusis (LASIK) to observe complications related to the interface and corneal flap. Wirbelauer used the instrument to observe and monitor the healing process before and after excimer laser phototherapeutic keratectomy (PTK) for recurrent epithelial erosions. Both groups concluded that OCT appears to be a promising method for evaluating anatomical changes within the cornea. However, the Stratus OCT does not incorporate the anterior segment application into its programming, and this device is not FDA approved or intended for this use.
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