Impact Of Descemet Membrane Endothelial Keratoplasty On Raytracing-Based Intraocular Lens Calculation
Published 2026 - 44th Congress of the ESCRS
Reference: FP13.15 | Type: Free paper | DOI: 10.82333/5jmc-rc92
Authors: Prof. Dr Joanna Wasielica-Poslednik* 1 , Ms Sarah-Ann Müller 1 , Mr Mohammad Ismail 1 , Dr Felix Wagner 1 , Prof. Dr Paul-Rolf Preussner 1
1Department of Ophthalmology,University Medical Center of the Johannes Gutenberg University Mainz,Mainz,Germany
Purpose
The combination of Descemet membrane endothelial keratoplasty (DMEK) and cataract surgery (triple-DMEK) has become a standard treatment for patients with both corneal endothelial disease and cataract. The aim of this study was to assess the purely cornea-induced refractive shift in intraocular lens (IOL) calculation in eyes undergoing triple-DMEK.
Setting
Retrospective data analysis.
Methods
Corneal tomography with two devices was performed before and 6 months after complication-free triple-DMEK. For each of four tomographic datasets, residual refractive error was calculated using full-aperture ray tracing. Identical IOL power, IOL model, lens position, and axial length were used; thus, differences reflected corneal data only. Refractive differences between pre- and postoperative conditions represented the DMEK-induced shift, whereas interdevice differences quantified measurement error. Donor corneal endothelial cell density and best-corrected visual acuity were recorded preoperatively and at 6 months.
Results
A total of 31 eyes from 24 patients were included. Mean refractive shifts in spherical equivalent measured with the two devices were 0.118 ± 0.641 D and 0.110 ± 0.644 D. The centroids of astigmatic differences were 0.60 D at 80° and 0.66 D at 93°. Mean corneal thickness decreased by 0.055 ± 0.044 mm and 0.063 ± 0.045 mm after DMEK. Preoperative donor endothelial cell density was 2561.94 ± 181.63 cells/mm² and decreased to 1633.03 ± 479.33 cells/mm² at 6 months, corresponding to a 36.3% reduction. No significant correlations were found between refractive shifts and changes in corneal thickness or endothelial cell density. Best-corrected visual acuity (logMAR) improved from 0.34 ± 0.17 to 0.04 ± 0.09 with consistent results overall.
Conclusions
The average cornea-induced refractive shifts calculated using full-aperture ray tracing following DMEK were small, on the order of approximately 0.1 D in spherical equivalent and 0.6 D in astigmatism, but showed relatively high standard deviations. Measurements obtained with the two tomographic devices were highly correlated and largely confirmed each other on average.