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Accuracy of intraocular lens power formulae involving 611 eyes: a retrospective data analysis

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First Author: V.Roggla AUSTRIA

Co Author(s):    A. Langenbucher   C. Leydolt   D. Schartmüller   L. Schwarzenbacher   C. Abela-Formanek   R. Menapace     

Abstract Details

Purpose:

To provide clinical guidance on the use of intraocular lens (IOL) power calculation formulae according to the biometric parameters.

Setting:

Department of Ophthalmology, Medical University of Vienna

Methods:

The predicted residual refractive error was calculated and compared to evaluate the accuracy of the following formulae: Haigis, Hoffer Q, Holladay 1 and SRK/T. Furthermore, the percentage of eyes with ≤±0.5dioptres (dpt) of the prediction error recorded. The subgroups analyzed were the axial length (AXL) groups: short (sAXL)< 22. 46 mm, medium (mAXL) 22.46mm to 24.64mm and long (lAXL) > 24.64mm and corneal radius groups: flat (fC) > 7.97mm, medium (mC) 7.97mm to 7.047mm, and steep (sC) < 7.47mm.

Results:

The Haigis formula showed the highest percentage of cases within 0.5dpt in short eyes with sC (90%), medium eyes with mC (68.8%) and sC (73.2%) but also in long eyes with fC (65%) and mC (72.7%). Hoffer Q and Holladay 1 formulae showed the lowest median absolute error (MedAE) in short eyes with mC (both 0.30dpt), equally in short eyes with sC (Holladay 1 0.24dpt and Hoffer Q 0.25dpt, respectively). SRK/T showed the highest percentage of cases within 0.5dpt in medium eyes with fC and the lowest MedAE in long eyes with mC (0.28dpt).

Conclusions:

Attention must be payed to the axial eye length as well as the corneal radius when choosing the appropriate formula to calculate an IOL power. The Haigis formula shows accurate results in most subgroups. The Holladay 1 formula can be recommended for short eyes and long eyes with a flat cornea. The Hoffer Q formula is precise for short eyes. The SRK/T can be used for short eyes with an average corneal curvature, eyes with an average length and a flat cornea and long eyes with an average cornea.

Financial Disclosure:

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