Comparison of automated versus traditional methods of RGP lens verification

Abstract

BACKGROUND The purpose of this study is two-fold. First, it will be demonstrated that there is no mean offset between base curve verification measurements obtained using a hand-held autokeratometer as opposed to the traditional verification method using a radiuscope. Secondly, the clinical perspective will be explored by presenting the likelihood of any significant difference which may be expected by a practitioner when measuring RGP base curves by automated means. METHODS Ninety-six RGP lens base curves were measured by two clinicians five times each by traditional radiuscope method and by use of an autokeratometer. RESULTS A statistical significant difference between the mean values of the traditional and automated methods of 0.007 mm existed. Clinically, this value is insignificant due to the +1- 0.02 mm error allowed by the ANSI standard for rigid gas permeable lenses. CONCLUSIONS Automated RGP base curve parameter verification using an Alcon Renaissance autokeratometer was found to be as clinically accurate as that done with the use of a radiuscope. Autokeratometer base curve verification also proved to be time efficient and cost effective