IOL power calculation by clinical scenario

Kane and Barrett Universal II are suitable starting points for routine biometry. Use ESCRS to compare predictions across formulas for the same IOL model.

Compare Kane and PEARL-DGS. The two network meta-analyses highlighted different formulas, which is why both are listed here.

Compare Kane and Barrett Universal II. For AL >28 mm, include Hill-RBF. Kane and Hill-RBF performed well in a meta-analysis of eyes in that range.

If historical keratometry and refraction are unavailable, select the myopic Barrett True-K No History mode. The ASCRS calculator can compare several methods.

Select the hyperopic treatment mode in Barrett True-K. If total keratometry has been measured, check whether your biometer offers Barrett True-K TK.

Select RK mode in Barrett True-K. For cross-checking, open the ESCRS post-RK section, which includes PEARL-DGS and EVO.

Use keratoconus-specific modes. In a network meta-analysis, Barrett True-K with measured posterior corneal curvature ranked highest overall. Kane Keratoconus is an option for cross-checking.

Compare Barrett Toric, Kane Toric and EVO Toric. Consider how posterior corneal astigmatism and effective lens position are accounted for. After LASIK or PRK, use the dedicated Barrett True-K Toric mode.

Start by cross-checking keratometry against corneal topography or tomography. Graft irregularity can materially affect the refractive prediction. Published evidence is insufficient to favour one formula across all such eyes.