To evaluate the accuracy of the chosen formula in short eyes and the effect of the anterior chamber depth (ACD) and corneal refractive power on the accuracy.

A total of 251 eyes out of 185 patients (axial length below 22.0 mm) who underwent cataract surgery in our hospital were retrospectively studied. Introcular lens (IOL) power was calculated with the Hoffer Q, SRK II, SRK-T and Holladay 1 formulas and refractive outcome was measured. Patients were divided into 2 groups based on ACD. The accuracy of the 4 formulas was compared and the errors according to the ACD were also evaluated.

In eyes with short axial lengths, all formulas showed a tendency for hyperopic shifts. The Hoffer Q formula showed significantly high predictive accuracy. This tendency for hyperopic shifts was similar in the eyes with extremely short axial length, but a large refractive error deviation was observed. The 2 groups based on ACD showed no significant difference in the refractive error, but the group with deep ACD had a tendency for hyperopic shifts. The difference of the calculated IOL power between the 4 formulas was more pronounced in eyes with lower corneal refractive power.

In eyes with short axial lengths, preoperative ACD and corneal refractive power had an influence on the accuracies of predicted IOL power. Therefore, these factors should be considered in IOL power determination.