Parameters Influencing Intraocular Lens Calculation In Patients With Triple Dmek
Published 2025 - 43rd Congress of the ESCRS
Reference: PO534 | Type: Free paper | DOI: 10.82333/rwv3-hr73
Authors: Nikolaus Luft* 1 , Roman Lischke 2 , Martin Dirisamer 3 , Siegfried G. Priglinger 1 , Martin Bechmann 4 , Rainer Wiltfang 4 , Walter Sekundo 5
1Ludwig-Maximilians-University,Munich,Germany, 2University Eye Hospital,Innsbruck,Austria, 3Smile Eyes Austria,Linz/Vienna,Austria, 4Smile Eyes Germany,Munich,Germany, 5Philipps University & UKGM Marburg,Marburg,Germany
Purpose
Indication of a combined triple DMEK procedure (Descemet's Membrane Endothelial Keratoplasty with cataract surgery) is strictly individual, considering the extent of dystrophic corneal changes, the degree of cataract, and the age of the patient. In our retrospective study we tried to determine parameters that influence intraocular lens calculation in this procedure to avoid a possible hyperopic shift which often occurs after this type of surgery due to changes in the characteristics of the cornea. We also evaluated changes in visual acuity and refraction.
Setting
Lexum Eye Clinics in Prague and Brno, Czech Republic.
Methods
The studied dataset included 60 eyes with cataract and Fuchs endothelial dystrophy of 54 patients (11 men, 43 women) who underwent triple DMEK procedure with intraocular lens implantation between 2019 and 2024. Mean patient age was 69 years (52 to 82 years), mean follow-up period was 13 months. When calculating the power of IOL, we used the SRK/T formula, and the target was set to a value of - 0.5 D sph to achieve emmetropia.
Preoperative vs. postoperative changes in keratometry (Mean K, ARC - Anterior Average Radii of Curvature; PRC - Posterior Corneal Radius; and TCRP - Total Corneal Refractive Power) and pachymetry were evaluated, as well as visual acuity at distance - uncorrected (UDVA) and corrected (CDVA), and refraction.
Results
We recorded only a slight change in preoperative vs. postoperative anterior mean-K (43.73 D vs. 43.38 D). Mean ARC changed from 7.72 mm to 7.79 mm after surgery. Mean PRC changed from preoperative 6.88 mm to postoperative 6.30 mm. Most important changes were recorded in TRCP values (43.60 D vs. 42.45 D), posterior mean-K (-5.85 D vs. -6.36 D), and apex pachymetry (622.60 µm vs. 535.49 µm).
Mean preoperative UDVA of 0.73 ± 0.38 logMAR improved to 0.22 ± 0.16 logMAR in eyes aimed for emmetropia. Preoperative CDVA changed from 0.37 ± 0.21 logMAR to 0.05 ± 0.08 logMAR after the surgery. In 30 eyes (50%) we observed a postoperative hyperopic shift. Mean difference between attempted and achieved sphere was 0.76 ± 0.87 D (-1.75 to 3.00 D).
Conclusions
Outcomes of our study showed that optimal calculation of the IOL power in patients with combined surgery should be based on keratometry from the anterior corneal surface, while values of the posterior corneal surface should be excluded from calculation. Despite a mild myopic target of -0.5 D sph when calculating IOL power, we recorded a hyperopic shift in 50% of studied eyes. This will need to be considered when planning further operations.
Nevertheless, substantial improvement of visual acuity together with shortening of postoperative visual recovery time, faster healing, and a reduction of the stress for the patient associated with the procedures, confirmed a benefit of triple DMEK in patients with cataract and Fuchs endothelial dystrophy.