Purpose:

The purpose of this study was to compare the performance and accuracy of two intraocular lens (IOL) power calculation formulae, Haigis and Barrett Universal II, on a Tecnis IOL platform in patients who have undergone either Manual Cataract Surgery (MCS) or Refractive Laser-assisted Cataract surgery (ReLACS).

Methods:

Retrospective chart review of patients who had pre-operative biometric testing done with IOL Master 700 using both Haigis and Barrett formulas and implantation of a Tecnis IOL. Predicted spherical equivalence (SE) from each formula was compared to the post-operative SE taken at one month. The Mean Absolute Error (MAE) and Median Absolute Error (MedAE) were compared for both formulae.

Results:

Of the 158 eyes studied, 64 eyes underwent MCS and 94 eyes underwent ReLACS. Baseline axial length (p=0.24), anterior chamber depth (p=0.21), cylinder (p=0.45), and IOL power (p=0.66) were similar between MCS and ReLACS eyes. Among all eyes, the MedAE was significantly less using the BII [BII: 0.21D vs. Haigis: 0.27D, p=0.004]. Among MCS eyes, the MedAE did not differ between the formulas [BII:0.21D vs. Haigis:0.23D, p=0.167], however among ReLACS eyes, BII was more accurate [BII:0.21D vs. Haigis: 0.27D, p=0.001]. BII was more likely to yield AE<0.5d among="" mcs="" eyes="" [bii:="" 57/64="" (89%)="" vs.="" haigis:="" 49/64="" (77%),=""><0.001), and="" among="" relacs="" eyes="" [bii:="" 81/94="" (86%)="" vs.="" haigis:="" 70/94="" (75%),=""><0.001).>

Conclusions:

Our results indicate that across all eyes, and specifically in eyes undergoing ReLACS, the Barrett Universal II formula led to greater refractive accuracy and likelihood of refractive success when compared to Haigis.