Analysis of posterior donor corneal parameters one-year after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) triple procedure

Although Descemet stripping automated endothelial keratoplasty (DSAEK) was demonstrated to be effective for the treatment of endothelial corneal diseases, a variable hyperopic shift has been measured as a common occurrence postoperatively. The aim of this work was to investigate the variance in the corneal and refractive responses to DSAEK combined with phacoemulsification and implantation of intra-ocular lens (IOL), namely the DSAEK triple procedure. The refractive, topographic, and anterior segment optical coherence tomography (AS-OCT) data of 23 eyes treated with DSAEK triple procedure were analyzed. A mean refractive IOL target of -1.04 +/- 0.09 D was calculated based on empirical data of our early experience to achieve emmetropia in all the eyes included in the study. Donor corneal parameters, i.e., graft diameter, thickness, and profile, were investigated in order to verify their possible role in the variable refractive shift after DSAEK. Although the 1-year mean refractive outcome was close to emmetropia (-0.01 +/- 0.89 D), the average difference between the targeted postoperative refraction and the 1-year postoperative spherical equivalent refraction was +0.98 +/- 0.87 D. Correlations of refractive change with central graft thickness (r = 0.36, p = 0.05) and graft diameter (r = 0.45; p = 0.03) were statistically significant. AS-OCT analysis revealed how the graft shape, with graft thicker in the periphery compared with the center, contributed to reduce the radius of curvature of the posterior cornea, thus favoring the hyperopic shift postoperatively. DSAEK triple procedure provides negligible changes in the surface topography, however with a variable amount of hyperopic shift postoperatively. Central graft thickness and graft profile together contributed to approximately two-thirds of the variance in refractive shift postoperatively. Lenticule diameter provided a minor influence on postoperative hyperopic shift than other graft parameters.