Leftover Astigmatism: The Missing Link Between Measured and Calculated Posterior Corneal Astigmatism

Abstract

Leftover astigmatism is clinically substantial. Because it is included in IOL cylinder power calculations based on refractive outcome, it may explain why methods of IOL cylinder power calculation using refractive outcome-based adjustments to anterior corneal astigmatism (previously described as adjustments for "posterior corneal astigmatism") are more successful than adjustment on the basis of measured posterior corneal astigmatism. <b>[<i>J Refract Surg.</i> 2022;38(9):559-564.]</b>.