Eyeworld Supplements

EW MAY 2017 – Sunday – Supported by Alcon A Novartis Division

This is a supplement to EyeWorld Magazine.

Issue link: https://supplements.eyeworld.org/i/824595

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2 V ario Data: After receiving the height data from the Topolyzer Vario (a device that is specifically selected to provide benchmark performance in centration and resolution in topography measurements), the Contoura Vision topography-guided ablation design begins with the calculation of the reference body. The median of the flat meridian (although both keratometry values are displayed at the planning screen of the WaveLight EX500) is used to shape the reference body. Additionally, the asphericity of the dataset imported is determined and used. If various datasets are imported, the median calculation will only include exams of the same day. The actual corneal shape is now fitted to the reference body. Differences in this calculated reference body are an- alyzed by a proprietary algorithm based on Zernike poly- nomials used for the later ablation profile calculation, and the difference of radii of the main meridians are translat- ed to C3 and C5 polynomial amplitudes. Exams containing at least 90% or more data within the optical zone will be activated by the algorithm and will be used for the reference body median calculation. To in- clude exams containing less than 90% of data points, the user may reduce the optical zone (e.g., from 6.5 mm to 6.0 mm). This decrease of optical zone will potentially result in surpassing the 90% criterion and will allow Contoura Vision surgery for patients where patients' anatomy might shadow the Placido ring projection. If desired, at this stage, the asphericity used for fitting the reference body can be modified. However, modifying the asphericity will affect the spherical aberration and po- tentially the achieved spherical correction. To eliminate obvious outliers, the general visual im- pression of the individual exams, but also some ancillary criteria such as the keratometry and its axis, the aspheric- ity, and with lower importance the pupil-size, can be used as criteria to identify outliers. Please see Important Product Information about the products mentioned in this supplement on pages 7-8. Zernike Fit Raw Data Sagittal Raw Data Tangential Contoura Vision Topography-Guided Ablation Algorithms Resulting Examination Profiles Sissimos Lemonis, is Director of Clinical Support at WaveLight GmbH in Erlangen, Germany. He can be contacted at sissimos.lemonis@alcon.com. Overview of imported exams Advanced Eye-Tracker options for the later treatment will only be available if an exam with good forecast status indication ( R ) is used. At this stage, the software will select one infrared image from the dataset, and that image will be marked with an asterisk (*). This identified infrared image is the closest to the median of the selected dataset imported. The image chosen may also be of red forecast status R (registration not possible); therefore, it is import- ant to only export infrared images with a green forecast status if registration is desired or indicated. The imported examinations and the resulting Examina- tion Profile can be displayed in various maps:

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