Raphael Diener1, Nicole Eter1, Maged Alnawaiseh2. 1. Dept. of Ophthalmology, University of Muenster Medical Center, Albert-Schweitzer-Campus 1, Building D15, 48149, Muenster, Germany. 2. Dept. of Ophthalmology, University of Muenster Medical Center, Albert-Schweitzer-Campus 1, Building D15, 48149, Muenster, Germany. maged.alnawaiseh@ukmuenster.de.
Abstract
PURPOSE: To evaluate different corneal parameters in identifying patients at risk of a hyperopic shift after (DMEK). METHODS: This retrospective study included 92 eyes of patients with FECD after DMEK surgery. Pachymetry parameters, various tomographic parameters and densitometry values before and after DMEK were determined using a rotating Scheimpflug system (Pentacam HR, Oculus). For assessing the posterior to anterior corneal curvature relationship, we calculated the RPA (posterior to anterior corneal curvature radii ratio). RESULTS: The average keratometry reading of the posterior corneal surface (KmB) increased and the total corneal refractive power (TCRP) decreased significantly after surgery (P < .001). There was a significant difference between the preoperative and postoperative RPA (P < .001) and the posterior Q value (P < .001). The strongest correlation was found between the change in the KmB and the preoperative RPA (Spearman's correlation coefficient = 0.872, P < .001). In the receiver operating characteristic (ROC) analysis, the highest AUC values (for ∆KmB) among the different preoperative parameters tested were obtained for RPA and posterior Q value (Asph. QB) with AUROC (area under the ROC) values of 0.95 and 0.89, respectively. CONCLUSIONS: The Q value and the RPA showed the highest correlation with the change in corneal refractive power and the greatest AUC. These parameters could be used as surrogate markers to identify eyes that might be at risk of a greater postoperative hyperopic shift, which would allow more accurate setting of refractive goals.
PURPOSE: To evaluate different corneal parameters in identifying patients at risk of a hyperopic shift after (DMEK). METHODS: This retrospective study included 92 eyes of patients with FECD after DMEK surgery. Pachymetry parameters, various tomographic parameters and densitometry values before and after DMEK were determined using a rotating Scheimpflug system (Pentacam HR, Oculus). For assessing the posterior to anterior corneal curvature relationship, we calculated the RPA (posterior to anterior corneal curvature radii ratio). RESULTS: The average keratometry reading of the posterior corneal surface (KmB) increased and the total corneal refractive power (TCRP) decreased significantly after surgery (P < .001). There was a significant difference between the preoperative and postoperative RPA (P < .001) and the posterior Q value (P < .001). The strongest correlation was found between the change in the KmB and the preoperative RPA (Spearman's correlation coefficient = 0.872, P < .001). In the receiver operating characteristic (ROC) analysis, the highest AUC values (for ∆KmB) among the different preoperative parameters tested were obtained for RPA and posterior Q value (Asph. QB) with AUROC (area under the ROC) values of 0.95 and 0.89, respectively. CONCLUSIONS: The Q value and the RPA showed the highest correlation with the change in corneal refractive power and the greatest AUC. These parameters could be used as surrogate markers to identify eyes that might be at risk of a greater postoperative hyperopic shift, which would allow more accurate setting of refractive goals.
Authors: Maged Alnawaiseh; André Rosentreter; Michael R R Böhm; Maria Eveslage; Nicole Eter; Lars Zumhagen Journal: Cornea Date: 2015-11 Impact factor: 2.651