Abstract
Purpose :
Surgeons continue to experience uncertainty regarding which IOL formula to use given both the plethora of available formulas and limited data regarding formula performance. To evaluate the accuracy and superior performance of 12 intraocular lens (IOL) formulas for long and short axial length eyes.
Methods :
12 IOL formulas (third generation and multivariable) were compared to assess refractive outcome predictability for short (< 22.0 mm) and long (> 26.0 mm) axial lengths (ALs) using a single IOL platform with swept source optical coherence tomography biometry. Normal AL eyes were included to optimize formulas’ lens constants on the entire AL range.
Results :
Formulas were ranked according to mean absolute error (MAE) for all (713), long (229), and short (111) ALs. The top formulas for each AL category were as follows: Long Eyes- K-6 (0.356), EVO (0.361), and Kane (0.361), while all but two formulas were statistically better than SRK/T (0.431); Short Eyes- Kane (0.393), EVO (0.402), and K-6 (0.309), while the worst formula was Hoffer Q (0.533).
Conclusions :
Predicted spherical equivalent outcomes were most accurate when using newer generation multivariable formulas. Kane, EVO, and K-6 formulas were top performers for both short and long ALs. While recommended by others historically, we strongly advise that the combination of SRK/T for long and Hoffer Q for short eyes no longer be encouraged given the availability of multivariable formulas. Surgeons may wish to consult specific online or biometry-integrated multivariable formulas when planning for short and long AL eyes.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.