Corneal back surface radius after DSEK and DSAEK: a comparative single surgeon case control study

The purpose of this study was to analyse and compare the visual and refractive results after DSEK with manual donor dissection and DSAEK with microkeratome-assisted donor dissection in a retrospective unmasked case control study. DSEK was performed in 15 eyes of 15 patients (74.9 ± 7.9 years; 4♂, 11♀). DSAEK was performed in 15 eyes of 15 patients (76.5 ± 6.6 years; 4♂, 11♀) using the Carriazo-Pendular-microkeratome and Schwindt artificial anterior chamber. The best corrected visual acuity (BCVA), corneal geometry assessed using Scheimpflug photography (SP) and anterior segment optical coherence tomography (AS-OCT) was regularly measured in 15 matched pairs receiving DSEK or DSAEK. Mean BCVA improved from 1.1 ± 0.5 to 0.5 ± 0.2 logMAR (p = 0.001) after DSEK and from 1.0 ± 0.5 to 0.2 ± 0.2 logMAR (p = 0.001) in the DSAEK-group. After 6 months, BCVA was significantly better in the DSAEK-group. Corneal refractive power decreased from 36.9 ± 1.5 to 35.9 ± 1.3 D (p = 0.01) in the DSEK-group and from 37.7 ± 1.6 to 36.4 ± 1.6 D (p = 0.01) in the DSAEK-group. The corneal back surface radius changed from 6.05 ± 1.6 to 5.82 ± 0.45 in the DSEK (p = 0.03) and from 6.72 ± 0.96 to 5.39 ± 0.33 in the DSAEK-group (p = 0.01). Mean central corneal thickness (CCT) measured by SP decreased from 741 ± 105 to 605 ± 63 µm (p = 0.26) after DSEK and from 700 ± 98 to 607 ± 88 µm (p = 0.01) after DSAEK. At no point in time during follow-up, mean CCT was significantly different in both groups. The ratio between central and peripheral transplant thickness decreased slightly from 0.65 ± 0.16 to 0.59 ± 0.16 after DSEK (p = 0.57) and from 0.52 ± 0.08 to 0.43 ± 0.14 after DSAEK (p = 0.17). The ratio difference between DSEK and DSAEK-groups was not statistically significant. The use of a pendular microkeratome for DSAEK results in faster visual rehabilitation but does not decrease the surgically induced change of cornea-based hyperopisation which is due to posterior corneal curvature.