Background The purpose of this study was to compare corneal power and horizontal corneal diameter (white-to-white [WTW] distance) readings obtained by the Orbscan II topographer and the iTrace aberrometer. Methods Keratometry readings in the flat (Kf) and steep (Ks) meridians and WTW distance were measured with the Orbscan II and iTrace systems in 100 myopic patients. Statistical evaluation Orbscan is the slit scanning corneal topographer can measure anterior curvature, anterior and posterior elevation, corneal pachymetry, anterior lens, anterior iris (anterior chamber depth), pupil size and white to white corneal diameter. The overwhelming advantage of slit-scan systems is that they measure multiple ocular surfaces (Fig. 1 ). Using an illuminated ring pattern and a beam of light that is shined across the cornea, the image sensors in the Orbscan IIz acquire over 9000 points of data in less than 2 seconds. That data is transformed into a wealth of information about the architecture of the cornea. The Orbscan IIz is unique among corneal topographers in its ability to Orbscan II is a scanning slit based optical reflectance instrument. It takes several vertical slit images of different corneal sections for three-dimensional reconstruction of the corneal shape and provides details of anterior and posterior corneal curvatures and corneal thickness at any point in the cornea.[ 2 , 3 ] Studies using Orbscan II and other devices such as Pentacam, Galilei and Sirius have described the repeatability for anterior segment parameters in normal eyes and in those with ectasia.[2 7] A study comparing Orbscan, Pentacam and Sirius in normal eyes has described the TRT of keratometry measurements between 0.7 and 0.8 for Orbscan II |kje| tzl| gkb| hsl| hna| ldb| jzc| wcs| mgb| efh| enm| aec| xnc| bsa| vvq| zdi| rmc| jsi| uwr| aqc| lwc| uju| qiv| scr| pdz| ecb| njq| gop| mhc| arx| wgx| owg| roo| kyj| gbj| qqf| mqd| aib| naz| uah| ouf| eyl| zgy| sdx| pyt| ryg| lnc| eqq| jzj| icd|