Determination of correction factors for intraoperative measurement of pseudophakic eyes

Session Details

Session Title: Cataract Surgery Outcomes: IOL Power Calculations

Session Date/Time: Sunday 08/10/2017 | 14:30-16:00

Paper Time: 15:36

Venue: Meeting Center Room I

First Author: : T.Tandogan GERMANY

Co Author(s): :    A. Cantagalli   M. Tetz   R. Khoramnia   C. Choi   G. Auffarth        

Abstract Details

Purpose:

Comparison of intraoperative aberrometry on pseudophakic eyes with the postoperative refraction. We have investigated if the prediction accuracy can be improved when using correction factors. These factors are determined for Abbott Tecnis® IOLs (Ar40e®, AAB00®, ZCB00®, ZCT00 & ZMB00®). We furthermore examined how this correction factors are affected by the IOL asphericity.

Setting:

International Vision Correction and Research Centre (IVCRC) & David J Apple Laboratory, Universitäts-Augenklinik Heidelberg (Germany) GSD Villa Erbosa, Bologna (Italy), Augentagesklinik-Spreebogen, Berlin (Germany)

Methods:

We analyzed in total 65 pseudophakic eyes with spherical and aspherical IOL of the Abbott Tecnis® IOL family. Immediately after implantation of the IOL suggested by an IOL-Power calculation formula based on preoperative biometry (NIDEK AL-Scan® or IOL Master®), a measurement is performed with the intra-operative wave-front analyzer I-O-W-A® (Eyesight&Vision GmbH, Germany). The intraoperatively determined refraction is compared with the subjective follow-up results acquired at least 6 weeks after surgery. From this comparison, we deduced correction factors for the Abbott Tecnis® IOL family.

Results:

The deviation could be corrected by IOL-specific offsets. We found correcting offsets between -0.1 D (AAB00®) and 1.2 D (ZCB00®) that have a strong correlation with the asphericity of the IOL. The offsets were independent of the surgeon. After implementing these correction factors a good prediction (100% within 0.8 dpt.) of postoperative refraction could be reached.

Conclusions:

The test series showed that it is possible to predict the final postoperative refraction of the patient by means of intraoperative measurement when the IOL-specific offsets are considered. The statistically determined offsets for each IOL type is essentially affected by the asphericity of the implanted IOL.

Financial Disclosure:

NONE