Where the rest of the people are not using any other iTrace, and most of the people are not having any experience with aberrometers. If you’re using aberrometers in your clinic, what is your preferred choice of aberrometry in your clinic? Zywave, WASCA, iTrace, Nidek OPD Scan, or any other aberrometer, or you’re not having any other experience with aberrometry? Let’s wait for the answer. Other studies have stated aberrometers based on the ray tracing principle and aberrometers based on the Hartmann-Shack principle should not be interchanged in clinical applications. And they found that higher order measurements, higher order aberration measurements obtained with iTrace tended to be larger than those obtained with Shack-Hartmann aberrometers and significant differences between the devices were found in coma measurements also. Rozema did a wonderful comparison of six aberrometers, and they found that all these aberrometers have different technical specifications, but when studied in normal healthy eyes they found that most of the parameters globally were similar, but there were some parameters in which there were significant differences. iTrace is based on the principle of ray tracing. The commercially available aberrometers, which are widely used worldwide, are Nidek OPD scan, WASCA, by Carl Zeiss Meditec, Zywave by Bausch and Lomb, multispot Hartmann, and Allegretto wave analyzer. The Zernike coefficients are represented as these Zernike polynomials, and the value is expressed in microns, and these values are expressed as bars, and these are displayed in iTrace. So the first two rows include lower order aberration, vertical tilt and horizontal tilt are included in first order aberration, oblique astigmatism, defocused and vertical astigmatism are included in second order aberration, while the bottom rows of this Zernike pyramid includes higher order aberration, vertical trefoil, horizontal coma, and oblique coma are included in third order, and vertical pentafoil, vertical secondary trefoil are included in fifth order aberrations. So how do we quantify wavefront aberrations? These wavefront aberrations are represented by Zernike mode pyramid, where m is the angular meridional frequency and n is the radial order. Do you have any aberrometer in your hospital? So it will be good to teach those people who are not having so much exposure to aberrometers. Higher order aberration causes blur and double voicing, glare and halo caused by spherical aberration, and starburst aberrations are caused by trefoil. Lower order consist of myopia and astigmatism. Aberrations are mainly lower order aberrations and higher order aberrations. And any departure from this parameter leads to a wavefront error. So what is wavefront aberration? It’s a measure of aberropia, the light coming from the distance, and whenever this passes through a convex lens, a spherical wavefront is formed. In the process of image formation by the human eye, the sources of degradation are diffraction, scattering, and most common is optical aberration. And ray tracing wavefront aberrometry and corneal topography fulfill this requisite. So today we are in the era of supranormal vision, where not only the surgeon, but patients also want vision beyond 20/20, and one can tailor patients’ outcomes with advanced different technology. So we’ll have a short talk on the basics of wavefront aberrometry and screening of patients with multifocal IOL candidates, dysfunction lens syndrome, dissatisfied refractive and multifocal patients, precision in toric IOLs, and other non-surgical applications of iTrace. And second are comprehensive ophthalmologists and ophthalmic technicians, and some of you are refractive surgeons. It’s good that most of our people are fellows today evening. What is your current position? Are you a cataract surgery? Are you a refractive surgeon? Comprehensive ophthalmologist? Fellow/resident, medical student, ophthalmic technician or allied health? So let’s see who has joined us today. So during the presentation, I will have a few poll questions for you, and I will be happy to take any queries and questions at the end of the presentation. I’m having no financial interest in this presentation. Neelam Pawar from India, and tonight I will be presenting on wavefront aberrometry and iTrace, screening and planning surgeries. DR PAWAR: Welcome to Cybersight live webinar.
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