Evaluation of Sum of Segments Biometry in Modern Intraocular Lens Power Calculation Formulas for Long Eyes

BUII formula showed myopic shift with SOS biometry which increases with longer eyes. Using SOS option in Cooke K6, EVO 2.0, and PEARL-DGS formulas leads to a hyperopic shift in the mean prediction error which is undesirable. Using ALsos in those formulas without choosing the option of SOS yields a mean prediction error towards the myopic side which might be more desirable. All included formulas performed well with ALsos with most of the cases within + 1 D of intended refraction.