Descemet Membrane Endothelial Keratoplasty vs Microthin Descemet Membrane Stripping Automated Endothelial Keratoplasty: A Randomised Controlled Trial

Abstract

Purpose : Best practice standards for corneal endothelial decompensation is evolving rapidly with the advent of Descemet Membrane Endothelial Keratoplasty (DMEK) and Ultrathin or Microthin Descemet Membrane Stripping Automated Endothelial Keratoplasty (UT-DSAEK or MT-DSAEK) with limited evidence so far comparing the two surgical techniques. We undertook a double blind randomised controlled trial to compare DMEK and MT-DSAEK in relation to visual outcome and complication rates.

Methods : 56 patients were randomised either to DMEK or the MT-DSAEK (28 eyes in each arm). Inclusion criteria included eyes with endothelial decompensation affecting vision but with no other ocular co-morbidities influencing visual potential. Patients randomised to each arm were matched for age, pre-operative Best Spectacle Corrected Visual Acuity (BSCVA). The primary outcome measure was BSCVA at 3, 6 and 12 months. Secondary outcome measures included keratometry, complication rates, endothelial cell density and visual related Quality of Life (QoL) with regression analysis and t tests utilised for statistical evaluation.

Results : Overall the study showed that the DMEK group had consistently better visual acuity than MT-DSAEK group. DMEK eyes had significantly improved logMAR BSCVA of 0.15±0.11, 0.10±0.14 and 0.04±0.13 at 3, 6 and 12 months respectively compared to 0.22±0.12, 0.17±0.09 and 0.11±0.09 in MT-DSAEK at similar time points (P< 0.05). The mean graft thickness in the MT-DSAEK was 61.0±12.7um. The graft detachment and primary failure rate was 0 % and 3.57 % in DMEK respectively compared to 3.57 % and 0 % in the MT-DSAEK group (P >0.05). Endothelial loss was similar between the groups and one eye in the MT-DSAEK group had a single graft rejection episode at 9 months. The mean Vision related QoL scores for the DMEK group was 73.2±17.4, 91.2±8.7 and 92.0±8.6 at 3,6 and 12 months compared to 69.2±15.7, 93.5±7.5 and 92.5±8.7 in MT-DSAEK (P > 0.05).

Conclusions : DMEK showed superior visual outcomes at 3, 6 and 12 months post operatively compared to MT-DSAEK with no demonstrable difference in post-operative complications. Patient reported outcomes however showed similar satisfaction rates between the groups. Our study renders clear support for adoption of DMEK over MT-DSAEK in eyes with simple endothelial decompensation with no other ocular comorbidity.

This is a 2020 ARVO Annual Meeting abstract.