First eye prediction error improves second eye refractive outcome results in 2129 patients after bilateral sequential...

To define theoretical correction factors for second-eye intraocular lens (IOL) power adjustment based on first eye refractive prediction error (PE).

Database study.

We included 2129 patients who underwent bilateral sequential phacoemulsification cataract surgery with the same IOL model.

Retrospectively calculated PEs (Hoffer Q, Holladay 1, SRK/T) were analyzed for association between paired eyes, examining the effect of interocular differences in axial length (AL) and corneal power. A range of correction factors (CF) derived from the first eye PE were applied to the second eye PE using optimized and non-optimized IOL constants (IOLCs).

Second eye mean absolute error (MAE).

Prediction errors of paired eyes were correlated. Interocular corneal power differences exceeding 0.60 diopters (D) were associated with a weaker correlation but interocular AL differences did not affect the correlation. When a 50% CF was applied to second eyes of patients with a first eye PE between ±0.50 and ±1.50 D, it improved refractive outcomes from 30%, 56%, and 92% to 42%, 75%, and 96% within ±0.25 D, ±0.50 D and ±1.00 D, respectively, and reduced the MAE from 0.49 to 0.37 D (P<0.0001). For first eye PE below ±0.50 D, a 50% CF reduced the MAE from 0.32 to 0.30 D (P<0.00001). A 50% CF also reduces second eye MAE for eyes with nonoptimized IOLCs.

A 50% CF reduces second eye PE when either first eye optimized PE is within ±1.50 D or when nonoptimized IOLCs are used. The correlation is weaker when interocular corneal power differences are >0.60 D.