Outcomes of Descemet's membrane endothelial keratoplasty performed in combination with, before, or after cataract surgery in Fuchs' endothelial dystrophy: A review of the literature and meta-analysis

This review aimed to compare the outcomes of Descemet's membrane endothelial keratoplasty (DMEK) in combination with (category 1), before (category 2), or after cataract surgery (category 3) in patients with Fuchs' endothelial dystrophy (FED). Primary outcome was gain in best-corrected log of minimum angle of resolution (logMAR) visual acuity (BCVA). Secondary outcomes were graft detachment, rebubbling rates, rejection, failure, and endothelial cell loss (ECL). In category 1, 2, and 3, 12 studies (N = 1932) were included (five in category 1 [n = 696], one in category 2 [n = 286], and two in category 3 [n = 950], and the remaining four compared between two of the three categories). At 6 months, the gain in BCVA was 0.34 +/- 0.04, 0.25 +/- 0.03, and 0.38 +/- 0.03 logMAR in category 1, 2, and 3, respectively. The difference was significant between categories 1 and 2 (Chi(2) = 11.47, P < 0.01) and categories 2 and 3 (Chi(2) = 35.53, P < 0.01). At 12 months, the gain in BCVA was 0.52 +/- 0.05 and 0.38 +/- 0.06 logMAR in categories 1 & 3 (Chi(2) = 14.04, P < 0.01). The rebubbling rates were 15%, 4%, and 10% (P < 0.01) and the graft detachment rates were 31%, 8%, and 13% (P < 0.01) in categories 1, 2, and 3, respectively. However, graft rejection, survival rates, and ECL at 12 months were not different between categories 1 and 3. There is low certainty evidence that gain in BCVA in category 1 was comparable to category 3 at 6 months; however, it was significantly better with category 3 at 12 months. Although rebubbling and graft detachment rates were highest in category 1, there was no significant difference in graft rejection, survival rates, and ECL. Further high-quality studies are likely to change the effect estimate and have an impact on the confidence of the estimate.