Abstract
Purpose: :
To investigate higher-order aberrations from the anterior/posterior corneal surfaces in post Descemet-stripping automated endothelial keratoplasty (DSAEK).
Methods: :
Enrolled patients were 30 eye of 30 normal subjects, 35 eyes of 29 patients who received penetrating keratoplasty (PKP) and 19 eyes of 19 patients who received DSAEK. The anterior/posterior corneal heights and pachymetric data were obtained with a rotating Scheimpflug camera (Pentacam, Oculus, Germany). Corneal higher-order aberrations (HOAs) for 4 mm pupils were calculated from the differences between the height data and the best-fit sphere, using an original program for each corneal surface. The reference axes of the measurements were aligned with the primary line of sight. The HOAs were expanded with normalized Zernike polynomials. For each pair of standard Zernike terms for trefoil, coma, tetrafoil, and secondary astigmatism, one value for the magnitude and axis was calculated by Zernike vector analysis.
Results: :
The mean total corneal HOAs (root mean square) from the anterior surface for normal eyes, post PKP eyes and post DSAEK eyes were 0.21±0.07µm, 1.40±0.71µm and 0.61±0.32µm, respectively. There was significant difference among the groups.(p<0.001, One Way ANOVA on Ranks)The mean total corneal HOAs from the posterior surface for those groups were 0.06±0.02µm, 0.20±0.10µm and 0.26±0.15µm, respectively. There was significant difference except between post PKP eyes and post DSAEK eyes.
Conclusions: :
Corneal HOAs on both anterior and posterior surfaces in post DSAEK eyes were significantly greater than those of normal eyes. However, compared with post PKP eyes, the HOA from the anterior corneal surface were significantly less and those from the posterior corneal surface were greater.
Keywords: aberrations • cornea: clinical science