Optimizing intraocular lens power calculations in eyes with axial lengths above 25.0 mm in an Asian population

Session Details

Session Title: Cataract Surgery Outcomes. IOL Power Calculations

Session Date/Time: Monday 07/09/2015 | 16:30-18:30

Paper Time: 17:34

Venue: Room 1

First Author: : J.Lim SINGAPORE

Co Author(s): :    G. Chew   V. Yong   L. Wang   D. Koch           

Abstract Details

Purpose:

To evaluate the accuracy of refractive prediction of 5 intraocular lens (IOL) power calculation formulas in eyes with axial length (AL) greater than 25.0mm and to propose a method of optimizing AL to improve the accuracy.

Setting:

National Healthcare Eye Institute, Department of Ophthalmology, Tan Tock Seng Hospital, Singapore

Methods:

Refractive prediction errors with the Holladay 1, Haigis, SRK/T, Hoffer Q and Barrett Univeral II formulas were evaluated in consecutive cases. Eyes with AL greater than 25.0mm underwent uncomplicated phacoemulsification and intraocular lens implantation by 2 surgeons. Their results were compared both for axial lengths that were from IOL Master and axial length that were optimized, except for Barrett Universal II formula.

Results:

Mean Numerical Error (MNE) for Holladay 1, Haigis, SRK/T, Hoffer Q and Barrett Universal II are 0.39 +/- 0.63, 0.19 +/- 0.47, 0.13+/-0.53, 0.50+/- 0.57 and 0.12 +/- 0.46 respectively. After optimizing the axial length the MNE for Holladay 1, Haigis, SRK/T and Hoffer Q are -0.21 +/- 0.47, -0.47 +/- 0.48, -0.17 +/- 0.49 and -0.17 +/- 0.52 respectively. Median Absolute Error (MAE) for Holladay 1, Haigis, SRK/T, Hoffer Q and Barrett Universal II are 0.45 (0.30,0.63), 0.25 (0.12,0.44), 0.33 (0.13,0.60), 0.37 (0.12,0.55) and 0.30 (0.09, 0.56) respectively. After optimizing the axial length the MAE for Holladay 1, Haigis, SRK/T and Hoffer Q are 0.30 (0.16,0.51), 0.26 (0.12,0.54), 0.36 (0.21,0.61) and 0.32 (0.17,0.57).

Conclusions:

The proposed method of optimizing AL in Holladay 1 improved accuracy, precision and reduced the percentage of long eyes with a hyperopic outcome. Haigis and Barrett Universal II formula also improved accuracy and precision without optimization of axial length.

Financial Interest:

NONE