Comparison of Anterior and Posterior Corneal Surface Irregularity in Descemet Stripping Automated Endothelial Keratoplasty and Penetrating Keratoplasty

Abstract

Postoperative corneal irregularity of the anterior surface was greater after PK than after DSAEK, whereas there was no significant difference in posterior surface irregularity. DSAEK is superior to PK in terms of the higher-order irregularity of the anterior surface.

Determinants of visual quality after endothelial keratoplasty

“…138 Posterior corneal HOAs were found to be significantly greater post-DSAEK than in normal eyes. 138 This study also demonstrated no significant difference in anterior HOAs between normal and post-DSAEK corneas, although there was a trend for greater anterior HOAs in the DSAEK group, 138 possibly representing a type 2 error.…”

“…5 Guerra et al reported that only 23% of DSAEK patients achieved VA >20/25 at 12 months follow-up, despite having otherwise healthy eyes and clear corneas with no evidence of graft failure, 44 and similar results with EK have been found by several others. 72,77,108,138 . Possible explanations for this include optical degradation at the graftrecipient interface, 64 increased corneal thickness, increased high order aberrations, stromal scarring and fibrosis secondary to the underlying pathology, and increased light scatter.…”

“…This has led some authors to reason that changes in the posterior cornea should not affect visual acuity. 54,138 Although correlation has been demonstrated between anterior corneal HOAs and postoperative BCVA, 84,108,137,139 several studies have failed to find a similar association between posterior corneal HOAs and postoperative BCVA. 68,81,84,133,137 Despite this, the impact of the posterior corneal surface on visual outcomes should not be ignored.…”

“…Therefore, central corneal thickness is greater post-DSAEK than post-PKP. 138 This has led to the suggestion that varying graft or total corneal thickness may explain the different visual outcomes after EK, 71,87,98,100 and this in turn has encouraged surgeons to strive for ever thinner grafts -with "ultrathin" DSEK (sub-100 micron) and DMEK being the latest incarnations.…”

Effects of corneal irregular astigmatism on visual acuity after conventional and femtosecond laser-assisted Descemet’s stripping automated endothelial keratoplasty

“…Although DSAEK has several advantages over penetrating keratoplasty (PK), such as rapid visual recovery, less postoperative astigmatism, fewer higher-order aberrations (HOAs) and a decreased rejection rate [3][4][5][6], not all patients achieve greater visual acuity, despite the improved corneal clarity DSAEK provides. The reasons for poor visual acuity after DSAEK include HOAs and interface or subepithelial opacities [7][8][9][10][11].…”