Article Text

Download PDFPDF

Extent and effect of surface tilt on the data display of the EyeSys videokeratoscope.
  1. W A Douthwaite,
  2. S Pardhan and
  3. H Burek
  1. Department of Optometry, Bradford University, West Yorks.


    AIMS: This study examined the occurrence, magnitude, and the consequences of a possible tilt between the corneal surface and optical axis of the EyeSys videokeratoscope. METHODS: Initially, a theoretical model was developed to calculate the angle of tilt. The predictions of the model were verified empirically using a convex conicoid surface and were found to predict the tilt to within 0.5 degree of the actual tilt. The likely effects of the tilt on the corneal power were also examined. The angle of tilt was then measured on the human cornea and the effect of neutralising the tilt on the videokeratoscopic data display was observed. RESULTS: The angle of tilt was found to lie between 1 degree and 6 degrees in a temporal direction. CONCLUSION: When the corneal tilt on the human subjects was neutralised, then a reduction in the nasal/temporal asymmetry was observed.

    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.