Intraocular lens power calculation for lens exchange

Purpose: To examine patients who had intraocular lens (IOL) exchange for la rge postoperative refractive errors and determine the factors that contribu ted to the error in IOL power calculation. Setting: Thirteen affiliated hospitals in japan. Methods: This study comprised 34 cases that required IOL exchange because o f large refractive errors after primary lens implantation. Patients with in traoperative complications were excluded from the study. The potential cont ribution of axial length, corneal refractive power, IOL manufacturer, and I OL fixation to errors in the predicted power was examined retrospectively. Axial length was calculated by the SRK/T and Holladay formulas using refrac tion after primary IOL implantation. Results: There was no statistical difference between the corneal refractive power before and after cataract surgery. The axial lengths calculated usin g the SRK/T and Holladay formulas were longer than the ultrasonic axial len gths in 24 and 23 cases, respectively. Using IOLs from the same manufacture r for both primary implantation and exchange reduced the error in predicted refraction. Conclusion: Axial length and IOL manufacturer were important factors in pre dicting refraction power in eyes requiring IOL exchange.