Feasibility and outcome of Descemet membrane endothelial keratoplasty in difficult situations

Abstract

Purpose: Descemet membrane endothelial keratoplasty (DMEK) is method of choice in Fuchs endothelial dystrophy and pseudophakic bullous keratopathy, but is is unclear whether DMEK can play a role in complicated situations. We hereby investigate if DMEK can serve as routine procedure in difficult pre-operative situations.

Methods: In this retrospective study, the outcome of DMEK in 22 eyes with difficult pre-operative situations was analyzed: Group 1: irido-corneo-endothelial (ICE) syndrome (n=3), group 2: aphakia, subluxation of intraocular lens (IOL), or anterior chamber lens (n=6), group 3: DMEK after trabeculectomy (n=4), group 4: DMEK after vitrectomy (n=3), group 5: DMEK combined with or followed by intravitreal bevacizumab injection for cystoid macular edema (n=6). Indication for DMEK was endothelial decompensation due to Fuchs endothelial dystrophy (n=2), ICE syndrome (n=3), and pseudophakic/aphakic bullous keratopathy (n=17). All patients of group 2 underwent IOL exchange with implantation of a scleral suture-fixated IOL before DMEK.<br /> Main outcome parameters were: best corrected visual acuity (BCVA), central corneal thickness (CCT), re-bubbling rate, and graft failure rate. Four eyes with ocular comorbidities influencing visual acuity (advanced glaucoma, macular degeneration) were excluded from analysis of the BCVA. Mean follow-up was 10 months (range 1 - 53 months).

Results: BCVA (logMAR) increased from 1.0 to 0.63, 0.60, and 0.73 after 1, 3 and 6 months, respectively (p=0.004). CCT decreased from 714 ± 170 µm to 566 ± 157 µm, 538 ± 76 µm, and 581 ± 97 µm after 1, 3 and 6 months, respectively (p=0.001). Re-Bubbling rate was 12/22 (55%). Eight patients suffered from graft failure between 0 (primary graft failure) and 36 months after DMEK (mean: 11 months). The highest rates of graft failure were found in group 3 (n=3) and group 5 (n=4).

Conclusions: Our data provide evidence that DMEK is feasibile in difficult situations as ICE syndrome, aphakia/subluxated IOL/anterior chamber IOL, after trabeculectomy, after vitrectomy and combined with bevacizumab injections. However, the re-bubbling rate and graft failure rate is higher compared to DMEK in uncomplicated situations. In eyes with unstable iris-lens-diaphragm (group 2), a two-step-procedure (1^st scleral suture-fixated IOL implantation, 2^nd DMEK) is recommended.