Changes in corneal refractive power and IOL power calculation for patients with Fuchs endothelial dystrophy after DMEK

Session Details

Session Title: Cornea: Surgical I

Session Date/Time: Sunday 08/10/2017 | 10:30-12:30

Paper Time: 11:56

Venue: Meeting Center Room I

First Author: : L.Zumhagen GERMANY

Co Author(s): :    N. Eter   M. Alnawaiseh                 

Abstract Details

Purpose:

To quantify changes in the refractive power of the anterior and posterior corneal surfaces after Descemet membrane endothelial keratoplasty (DMEK) to optimize the accuracy of intraocular lens (IOL) power calculations.

Setting:

University Eye Hospital Muenster, Germany

Methods:

Scheimpflug-based Oculus Pentacam imaging was performed after DMEK surgery for Fuchs endothelial dystrophy. The IOL power was calculated for all patients by ray tracing, aiming for postoperative emmetropia. We also performed the IOL calculation using four third-generation formulas (SRK-T, Hoffer-Q, Holladay-1 and Haigis). The residual refractions for the individual target IOL were compared and analyzed.

Results:

This retrospective study included 42 eyes of 33 patients (age 68.73±10.11 years) after DMEK surgery. The differences between the expected residual refraction based on ray tracing and that predicted with the third-generation formulas were statistically significant (all formulas p<0.001). The highest mean difference in the residual refraction between the target IOL measured by ray tracing and that calculated with third-generation formulas was found for the Haigis formula (0.89±0.42 D), and the lowest mean difference for the SRK/T formula (0.70±0.51 D).

Conclusions:

DMEK surgery induced a relevant change in the anterior to posterior corneal curvature relationship. Therefore IOL power calculation only based on the anterior corneal surface will lead to a hyperopic refractive surprises. This needs to be taken into account and IOL power calculation should better be based on the total corneal refractive power generated by ray tracing of the complete cornea.

Financial Disclosure:

NONE