AAO 2015
    Cornea/External Disease, Refractive Mgmt/Intervention

    This video asserts that placido-based ectasia is an essential adjunct to accurate ectasia detection and can help with recognition of early ectasia that might be less evident using elevation based technology. It is easily the best known and most widely available method for corneal shape assessment and directly measures corneal power, as opposed to other technologies, which employ a derivative of elevation data.