IOL Power Calculation in the Short Eye

Short eyes include simple microphthalmos, complex microphthalmos, nanophthalmos, relative anterior microphthalmos, and posterior microphthalmos. The definition of each of these subgroups is given, as well as the possible genetic mutations leading to these anatomical characteristics. In short eyes, the ELP prediction is a critical parameter for IOL power calculation. Formulas that take both the anterior chamber depth and lens thickness into account are likely to achieve more accurate outcomes, but the results are still far from being perfect with more than 40% of eyes showing a prediction error >±0.50 D when the axial length is <21.5 mm. Primary and secondary piggy-back implantation is reviewed.