corneal topography การใช้

• Corneal topography and pachymetry are used to screen for abnormal corneas.
• The gold standard diagnostic test for PMD is corneal topography.
• Corneal topography may also be used to obtain a more accurate representation of the cornea's shape.
• The surgeon can ascertains the astigmatic, or steepest, meridian in a number of ways, including manifest refraction or corneal topography.
• Thus, if corneal topography is used for diagnosis, it should be in conjunction with clinical findings of peripheral, inferior corneal thinning.
• A modern development of the concept is found in corneal topography, in which analysis of the reflected image is passed to a computer.
• When treating a patient with preexisting astigmatism, most wavefront-guided LASIK lasers are designed to treat regular astigmatism as determined externally by corneal topography.
• Corneal topography may show a " crab claw-like " appearance, a finding that is seen in both keratoconus and in pellucid marginal degeneration.
• Abnormal corneal topography compromises of keratoconus, pellucid marginal degeneration, or forme fruste keratoconus with an I-S value of 1.4 or more is the most significant risk factor.
• People that are considered for treatment must undergo an extensive clinical workup, including corneal tomography, computerized corneal topography, endothelial microscopy, ultrasound pachymetry, b-scan sonography, keratometry and biomicroscopy.
• Some of these approaches are programmed into the devices ophthalmologists use to measure the refraction of the eye and the shape of the cornea, such as corneal topography.
• BENSON EYECARE CORP ., New York, which distributes eyeglasses and operates wholesale laboratories that serve ophthalmologists, sold its corneal topography business to Humphrey Instruments, a division of Carl Zeiss Inc.
• A more definitive diagnosis can be obtained using corneal topography, in which an automated instrument projects the illuminated pattern onto the cornea and determines its topography from analysis of the digital image.
• A development of keratoscopy, corneal topography extends the measurement range from the four points a few millimeters apart that is offered by keratometry to a grid of thousands of points covering the entire cornea.
• By using a common eye measurement instrument called a corneal topography device with the same spline equations that are used to create cinematic special effects, doctors could one day measure the cornea's surface down to the tiniest micron.
• "Normally with corneal topography, if I move my eye, the measurements will change, which is incorrect, since my eye did not really change shape, " said Barsky, who is talking with contact lens companies that are interested in his invention.
• However, it was not until computerized corneal topography became available during the 1990s that it became possible to apply the theory to create designs with repeatable results through being able to accurately map the surface curvature of the cornea using a non-invasive, painless imaging procedure.