title: Characteristic higher-order aberrations of the anterior and posterior corneal surfaces in 3 corneal transplantation techniques.
abstract: OBJECTIVE
  To investigate the corneal higher-order aberrations (HOAs) of the anterior and posterior corneal surfaces in eyes that underwent penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), and Descemet stripping automated endothelial keratoplasty (DSAEK).
  
  
  METHODS
  Retrospective, case-control study.
  
  
  METHODS
  study population: Twenty-four eyes underwent PK, 28 eyes underwent DALK, and 19 eyes underwent DSAEK; 29 normal eyes served as controls. observation procedures: The anterior and posterior corneal heights and pachymetric data were obtained with a Scheimpflug-based corneal topographer. Corneal HOAs for 4-mm pupils were calculated from the height data and were expanded with normalized Zernike polynomials. The HOAs resulting from the anterior and posterior corneal surfaces were compared among the procedures. main outcome measures: Anterior and posterior corneal HOAs (root mean square).
  
  
  RESULTS
  Control eyes had significantly lower total HOAs and Zernike vector terms of the anterior and posterior surfaces than the other groups, except for spherical aberration. The mean anterior corneal surface total HOAs in the PK, DALK, DSAEK, and control groups were 1.38 ± 0.67 μm, 1.19 ± 0.57 μm, 0.61 ± 0.33 μm, and 0.21 ± 0.07 μm, respectively. The anterior corneal HOAs in the DSAEK group were significantly less than those in the PK group (P < .001) and DALK group (P < .001). The mean posterior corneal surface total HOAs were, respectively, 0.20 ± 0.09 μm, 0.24 ± 0.11 μm, 0.27 ± 0.15 μm, and 0.07 ± 0.02 μm. There were no significant differences in the posterior corneal HOAs among the treatment groups.
  
  
  CONCLUSIONS
  Because the refractive indices between the anterior and the posterior surfaces differed greatly, eyes that undergo DSAEK have lower anterior corneal HOAs compared with PK or DALK eyes. However, the anterior and posterior corneal HOAs in DSAEK eyes still were greater than those in control eyes.
authors: Department of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors: Shizuka
authors: S
authors: Koh
authors: Naoyuki
authors: N
authors: Maeda
authors: Tomoya
authors: T
authors: Nakagawa
authors: Ritsuko
authors: R
authors: Higashiura
authors: Makoto
authors: M
authors: Saika
authors: Toshifumi
authors: T
authors: Mihashi
authors: Takashi
authors: T
authors: Fujikado
authors: Kohji
authors: K
authors: Nishida
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D003316:Corneal Diseases / Q000601:surgery; D019781:Corneal Topography; D016039:Corneal Transplantation; D057108:Corneal Wavefront Aberration / Q000503:physiopathology*; D057111:Descemet Stripping Endothelial Keratoplasty; D004728:Endothelium, Corneal / Q000503:physiopathology*; D019573:Epithelium, Corneal / Q000503:physiopathology*; D006801:Humans; D015948:Keratoplasty, Penetrating; D008875:Middle Aged; D012189:Retrospective Studies