title: Changes in Corneal Refractive Power for Patients With Fuchs Endothelial Dystrophy After DMEK.
abstract: OBJECTIVE
  To quantify changes in the refractive power of the anterior and posterior corneal surfaces after Descemet membrane endothelial keratoplasty (DMEK) so as to optimize the accuracy of intraocular lens (IOL) power calculations.
  
  
  METHODS
  This study included 28 eyes of 21 patients (age 66.6 ± 9.4 years, 11 female, 10 male). Scheimpflug-based Oculus Pentacam imaging was performed before and after DMEK surgery for Fuchs endothelial dystrophy. Corneal power was measured using the K-value of simulated keratometry (SimK) of Pentacam and total corneal refractive power (TCRP) in corneal zones from 1 to 8 mm (SimK 1-8, TCRP1-8). We also analyzed changes in the keratometric power deviation (KPD) and pachymetry.
  
  
  RESULTS
  Changes in the SimK in the central cornea were minimal and not significant (SimK 3: before = 43.24 ± 1.33 D; after = 43.01 ± 1.37 D; P = 0.101) but they decreased significantly in the corneal periphery (SimK 4: P = 0.021; SimK 5: P = 0.004; SimK 6: P = 0.002; SimK 7: P = 0.002; SimK 8: P = 0.008). Postoperative TCRP in the central cornea decreased significantly compared with preoperative values (TCRP 3: before = 43.05 ± 1.44 D; after = 41.94 ± 1.34 D; P < 0.001); [TCRP 4: before = 43.16 ± 1.40 (D); after = 41.99 ± 1.27 (D); P < 0.001]. The keratometric power deviation increased significantly after DMEK (before = 0.74 ± 0.45 D; after = 1.40 ± 0.26 D; P < 0.001).
  
  
  CONCLUSIONS
  DMEK surgery induced a significant change in the refractive power of the posterior surface of the cornea and thus a decrease in the TCRP of about 1 D, whereas the SimK, which measures only the anterior cornea, remained nearly unchanged. To avoid a hyperopic surprise, it is essential that this TCRP decrease is not overlooked in intraocular lens power calculations.
authors.affiliation: Department of Ophthalmology, University of Muenster Medical Center, Muenster, Germany.
authors.forename: Maged
authors.initials: M
authors.lastname: Alnawaiseh
authors.forename: Andre
authors.initials: A
authors.lastname: Rosentreter
authors.forename: Nicole
authors.initials: N
authors.lastname: Eter
authors.forename: Lars
authors.initials: L
authors.lastname: Zumhagen
mesh_terms: D000368:Aged; D003315:Cornea / Q000503:physiopathology*; D019781:Corneal Topography / Q000379:methods; D057111:Descemet Stripping Endothelial Keratoplasty; D005260:Female; D005642:Fuchs' Endothelial Dystrophy / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D014792:Visual Acuity