Diagnostic clues in keratoconus. Scheimpflug is better?

Although the identification of early forms of keratoconus during refractive screening would probably be the most appropriate method to prevent postoperative ectasia, the detection of this preclinical stage often pose challenges to clinicians. Moreover, for any tomographic or topographic parameter a significant overlap exists between keratoconus suspects and normal eyes resulting in lower sensitivity and specificity in identifying corneas with mild ectasia compared to detecting keratoconus. In this lecture, we describe the topographic and tomographic characteristics of preclinical keratoconus in paralell with the comparison of the accuracy of different paramateres in discriminating normal corneas from eyes with early keratoconus.