J A Armitage1, A S Bruce, A J Phillips, R G Lindsay. 1. Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia. j.armitage@optometry.unimelb.edu.au
Abstract
PURPOSE: Two morphological cone variants are identified in keratoconus; nipple and oval. The present study was designed to assess the impact of aetiological factors on cone morphology. METHODS: As part of a prospective controlled study, keratoconic subjects from a suburban practice (n = 89) underwent videokeratograph examination and completed a questionnaire detailing aetiological factors. RESULTS: Comparison of 95% confidence limits (CL; bootstrap method) for apical power between the two cone morphology groups showed no statistical significance. Oval cones were located at a greater eccentricity than nipple cones, as their definitions suggest. Associations between aetiological factors examined and the morphology of the cone were not significant (bootstrapped 95% CL). CONCLUSION: Despite the suggestion of morphological variants in keratoconus, the results of the present study suggest a common cone aetiology.
PURPOSE: Two morphological cone variants are identified in keratoconus; nipple and oval. The present study was designed to assess the impact of aetiological factors on cone morphology. METHODS: As part of a prospective controlled study, keratoconic subjects from a suburban practice (n = 89) underwent videokeratograph examination and completed a questionnaire detailing aetiological factors. RESULTS: Comparison of 95% confidence limits (CL; bootstrap method) for apical power between the two cone morphology groups showed no statistical significance. Oval cones were located at a greater eccentricity than nipple cones, as their definitions suggest. Associations between aetiological factors examined and the morphology of the cone were not significant (bootstrapped 95% CL). CONCLUSION: Despite the suggestion of morphological variants in keratoconus, the results of the present study suggest a common cone aetiology.