Comparison of Intraoperative Aberrometry and Koch-Wang Formula for IOL Calculations in Eyes With Axial Lengths Longer Than 25.0 mm

Monday, April 20, 2015: 8:41 AM
Room 5A (San Diego Convention Center)
Nicole R. Fram, MD
Samuel Masket, MD

To evaluate accuracy of intraoperative aberrometry proprietary nomogram as compared to Koch-Wang formula in predicting intraocular lens power in eyes with axial lengths above 25.0 mm.

Retrospective review of  23 eyes of 23 patients undergoing cataract surgery between 2013-2014 with a single platform intraocular lens and axial lengths >25.0 mm. intraoperative aberrometry (ORA, WaveTec) and Holladay-1 adjusted Koch-Wang formula refractive prediction errors were compared. Consecutive eyes with axial lengths >25.0 mm undergoing cataract surgery with intraocular lens implantation were included in the study. Eyes with a prior history of laser vision correction, pre-existing corneal pathology, significant macular disease or staphylomas or were excluded from the study. Main outcome measures included refractive IOL prediction error, mean absolute error and median absolute error.

In 23 eyes of 23 patients the Koch-Wang formula resulted in a refractive IOL prediction error of 70% within +/-0.25 D and 100% within +/-0.50 D, +/-0.75 D and +/-1.00 D. Intraoperative aberrometry resulted in 60% of eyes within +/-0.25 D, 90% within +/-0.50 D and 100% within +/-0.75 D and +/-1.00 D. The mean absolute refractive error was 0.20 for the Koch-Wang formula and 0.28 for Intraoperative aberrometry. The median absolute refractive error was 0.11 and 0.22 for the Koch-Wang formula and intraoperative aberrometry, respectively. Statistical significance was not achieved.

Intraoperative aberrometry appears to be comparable to the Koch-Wang formula for accurate intraocular lens calculations in eyes with axial lengths >25.0 mm.