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

Ophthalmology. 2011 Sep;118(9):1701-9. doi: 10.1016/j.ophtha.2011.05.010. Epub 2011 Jul 16.


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

Design: Database study.

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

Methods: 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).

Main outcome measures: Second eye mean absolute error (MAE).

Results: 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.

Conclusions: 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.

MeSH terms

  • Diagnostic Errors*
  • Functional Laterality / physiology*
  • Humans
  • Lens Implantation, Intraocular
  • Lenses, Intraocular*
  • Models, Theoretical
  • Phacoemulsification*
  • Prospective Studies
  • Refraction, Ocular / physiology*
  • Refractive Errors / diagnosis*
  • Visual Acuity / physiology*