Abstract
Purpose: :
To evaluate differences in posterior corneal wavefront aberrations between post-descemet stripping and automated endothelial keratoplasty (DSAEK) and post-femptosecond-guided penetrating keratoplasty (IEK) corneas as compared to healthy age-matched normal corneas.
Methods: :
10 eyes of 9 patients who had the DSAEK , 20 eyes of 18 patients who had IEK, and 16 eyes of 8 age matched non-surgical patients were compared for differences in posterior corneal curvature aberrations using rotating Scheimpflug photography. Averages of root mean square (RMS) values of Zernike polynomial vectors for each 1st through 8th order aberrations were compared for statistical differences using student T test and single factor analysis of variance.
Results: :
3-6 months after surgery, compared to normal corneas, the posterior surface of post-IEK corneas only had significant differences in oblique astigmatism and 6th and higher order aberrations. In contrast, post-DSAEK corneas had significantly more defocus, astigmatism, coma, trefoil, tetrafoil and a majority of 5th to 8th order aberrations than normal corneas.
Conclusions: :
Changes in central contour of the posterior corneal surface after DSAEK and IEK surgeries are not visible on slit lamp exam. However, the more prominent aberration patterns induced by DSAEK surgery may have a greater impact on optical performance than those of a full thickness corneal transplant done with the femtosecond laser. This may explain, at least in part, the lower levels of best spectacle corrected visual acuity in DSAEK compared to femtosecond laser PKP.
Keywords: refractive surgery: other technologies • cornea: clinical science • refractive surgery: comparative studies