![]() When poor vision occurs after a premium lens implantation, an undilated scan with the iTrace will bring the root cause to light. ![]() Since the iTrace is the only device that can accurately scan the complex architecture of a premium IOL, these post-surgical benefits are not exclusive to toric lenses. A surgeon can easily review the estimated benefits of rotating a toric lens with a patient after understanding how much cylinder is likely to change. The iTrace’s wavefront map displays both the axis of the cylinder internally and the corneal steep axis, which is confirmed by topography.īecause ray tracing is the only way to accurately measure through a toric lens, the iTrace is the only device that calculates the predicted post-surgical refraction and automatically suggests any rotation that will optimize the location of a toric lens. The iTrace calculates cross cylinder and verifies whether a toric IOL is off-axis or off-power.Īfter a toric implantation, the lens cylinder power should match the corneal steep axis. ![]() Determining the post-operative axis location does not need to be a time-consuming or uncomfortable process. Limits of agreement of 95% showed very little variation among normal adults, indicating that measurements of 0.392 for PSF, 0.547 for MTF, and 3.81 for RMS may be considered "normal" values and useful in comparison with a diseased population to determine contrast sensitivity loss.A 30-second iTrace exam evaluates the post-operative alignment of a toric lens without dilating a patient. Using Cronbach’s alpha analysis, we were able to confirm the reliability of the iTrace ray tracing wavefront aberrometer and corneal topographer to measure point spread function, modulation transfer function, and root mean square outputs, which are all indirect measurements of contrast sensitivity. A 95% confidence interval for the mean of the point spread function ranged from 0.3116 to 0.4837 with an average of 0.392, for modulation transfer function 0.47 to 0.572 with an average of 0.547, and for root mean squared 3.43 to 4.00 with an average of 3.81. Refractive status for sphere, cylinder and axis was also analyzed by Cronbach’s alpha analysis and all values were above 0.9 for both the right and left eyes. Cronbach alpha for point spread function analysis was 0.912 OD and 0.886 OS, modulation transfer function was 0.936 for OD and 0.898 OS, Mean Root Square was. Test-retest reliability was confirmed utilizing Cronbach’s alpha analysis. The device uses a single beam refractometer based on the retina for tracing and. Normal contrast sensitivity was verified utilizing subjective measurement MARS chart at a distance of 40 cm, with mean luminance of 85 cd/m 2. The Tracey iTrace is a wavefront aberrometer designed by Tracey Technology. All subjects had BCVA of 20/20 OD and OS and were free of any ocular pathology. Each measurement was repeated 3 times and testing was conducted uncorrected. Twenty-five visually normal adults (n=50 eyes mean age = 27.56 ± 3.2 years age range 25-39 years), were tested on the iTrace ray tracing wavefront aberrometer and corneal topographer. To determine whether the iTrace ray tracing wavefront aberrometer and corneal topographer reliably measures contrast sensitivity and refractive error.
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