Author Block: Maia A. Idzikowski, George Mintsioulis, Davin Johnson.

Disclosure Block: M.A. Idzikowski: None. G. Mintsioulis: None. D. Johnson: None.

Purpose: To compare refractive outcomes of intraoperative wavefront aberrometry versus preoperative biometry in patients undergoing cataract surgery and refractive lens exchange.
Study Design: Retrospective chart review of 204 consecutive eyes with both preoperative biometry (IOL Master 700) and intraoperative aberrometry (Optiwave Refractive Analysis (ORA)) data.
Methods: The predicted vs. postoperative spherical equivalent was compared between ORA and preoperative biometry. For eyes with no history of refractive surgery we used the Barrett TK Universal II (Barrett TK2) formula. For eyes with a history of refractive surgery, we compared the ORA with 3 preoperative calculation methods (Barrett True K, Shammas, and Haigis-L).
Results: In eyes with no history of refractive surgery (n=178), there was no significant difference in mean absolute error (MAE) between the Barrett TK2 and ORA (0.28 vs 0.27 D, p=0.45); the proportion of eyes within 0.5D of target was also similar between the two groups (85.1 vs. 87.9, p=0.43). Excluding eyes with axial myopia (>25mm), the mean absolute error was smaller with the ORA vs. Barrett TK2 (0.25 vs. 0.29D, p=0.018) although the proportion of eyes within 0.5D of target was similar (84.1% for Barrett TK2 vs. 88.5% for ORA, p=0.33). In eyes with a history of myopic LASIK/PRK (n=18), the MAEs for the Barrett True K, Shammas, Haigis-L, and ORA were 0.33, 0.65, 0.60, and 0.38, respectively, with 77.8, 41.2, 52.9 and 77.8% of eyes within 0.5D of target. In eyes with a history of hyperopic LASIK/PRK (n=8), the MAEs for the Barrett True K, Shammas, Haigis-L and Ora were 0.22, 0.40, 0.67, and 0.56, respectively, with 87.5, 57.1. 28.6 and 37.5% of eyes within 0.5D of target.
Conclusions: Both the Barrett TK2 and ORA device are highly accurate in IOL prediction in eyes without a history of refractive surgery; the ORA may confer a small benefit although the effect size is small and both techniques likely approach a theoretical ceiling of refractive accuracy. In a small subset of eyes with a history of refractive surgery, the ORA was not superior to the Barrett True K, Shammas, or Haigis-L formula.