Influence of graft thickness and regularity on vision recovery after endothelial keratoplasty

Abstract

Aim: To assess the influence of graft thickness and regularity on visual recovery and postoperative wavefront aberrations after endothelial keratoplasty (EK).

Methods: 150 EKs performed in eyes with corneal endothelial disorders and no other ocular comorbidities, preoperative and postoperative assessment with spectral domain optical coherence tomography and postoperative assessment with whole eye wavefront aberrometry were retrospectively analysed. Eyes were classified into five groups: Descemet Membrane Endothelial Keratoplasty (DMEK), nanothin Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) (15-49 µm), ultrathin DSAEK (50-99 µm), thin DSAEK (100-149 µm) and conventional DSAEK (150-250 µm).

Results: The preoperative diagnosis was Fuchs dystrophy in 139 eyes (92.7%). The graft thickness measured after graft deswelling was in average 74 µm with a mean coefficient of variation of 17%. The average follow-up time was 32 months. The mean spectacle-corrected logarithm of minimum angle of resolution visual acuity improved from 0.76 (20/116) before surgery to 0.14 (20/27) at last follow-up visit. No significant differences in final visual acuity were found between the five groups. The time to reach 20/40 vision was significantly shorter in the DMEK and nanothin DSAEK groups compared with the remaining three DSAEK groups. No significant differences in postoperative aberrometry measurements were found between the five groups. Shorter time to reach 20/40 visual acuity was associated with better preoperative visual acuity and thinner graft. Higher final vision improvement was associated with poorer preoperative visual acuity. Higher postoperative high-order aberrations were associated with poorer preoperative visual acuity.

Conclusion: The main advantage of DMEK and nanothin DSAEK over thicker DSAEKs was the rapidity of visual recovery. Final quality of vision was not influenced by graft thickness and regularity.

Keywords: DMEK; DSAEK; aberrometry; cornea; endothelial keratoplasty.