Feasibility and Outcome of Descemet Membrane Endothelial Keratoplasty in Complex Anterior Segment and Vitreous Disease

CLINICAL SCIENCE

Julia M. Weller, MD, Theoﬁlos Tourtas, MD, and Friedrich E. Kruse, MD

escemet membrane endothelial keratoplasty (DMEK), Purpose: Descemet membrane endothelial keratoplasty (DMEK) is Da technique for posterior lamellar keratoplasty, involves becoming the method of choice for treating Fuchs endothelial a graft consisting only of the thin Descemet membrane with dystrophy and pseudophakic bullous keratopathy. We investigated adherent corneal endothelial cells. Introduced in 2006 by whether DMEK can serve as a routine procedure in endothelial Melles et al,1 DMEK is becoming more popular as several decompensation even in complex preoperative situations. studies show its superiority to Descemet stripping automated Methods: Of a total of 1184 DMEK surgeries, 24 consecutive eyes endothelial keratoplasty (DSAEK), regarding visual function 2,3 with endothelial decompensation and complex preoperative situa- and the time of visual rehabilitation after DMEK. However, tions were retrospectively analyzed and divided into 5 groups: group because DMEK grafts are thinner than DSAEK grafts, it is fi 1: irido-corneo-endothelial syndrome (n = 3), group 2: aphakia, more dif cult to handle them and typically takes surgeons subluxated posterior chamber intraocular lens or anterior chamber longer to learn. intraocular lens (n = 6), group 3: DMEK after trabeculectomy (n = In difficult situations, most surgeons prefer DSAEK or 4), group 4: DMEK with simultaneous intravitreal injection (n = 6), penetrating keratoplasty to DMEK because of its possible and group 5: DMEK after vitrectomy (n = 5). Main outcome intraoperative complications. For example, if corneal edema 4 parameters were best-corrected visual acuity, central corneal thick- is advanced, Ham et al recommend performing DSAEK first ness, endothelial cell density, rebubbling rate, and graft failure rate. to achieve clearance of corneal stroma, and then performing DMEK second for better visual results. Results: Best-corrected visual acuity (logMAR) increased from 0.98 Nowadays, DMEK surgery is becoming more standard- to 0.53 (P = 0.002), 0.53 (P = 0.091), and 0.57 (P = 0.203) after 1, 3, ized with the predictable success and good reproducibility of and 6 months, respectively. Central corneal thickness decreased from graft preparation.5 However, the feasibility of DMEK is 731 6 170 to 546 6 152 mm(P = 0.001), 514 6 66 mm(P = 0.932), dependent on 3 morphological features of the eye: (1) and 554 6 98 mm(P = 0.004) after 1, 3, and 6 months, respectively. anatomy of the anterior chamber, (2) situation of the iris– 6 6 Donor endothelial cell density decreased from 2478 185 to 1454 lens diaphragm, (3) status of the vitreous. 2 , 6 2 6 193/mm (P 0.001), 1301 298/mm (P = 0.241), and 1374 261/ Both a shallow and a very deep anterior chamber make 2 mm (P = 0.213), after 1, 3, and 6 months, respectively. The rebubbling the handling and unfolding of the graft difficult. A stable iris– rate was 46% (11/24). Four patients (17%) had secondary graft failure. lens diaphragm is required because during and at the end of Conclusions: Our data provide evidence that DMEK is feasible for surgery, an air bubble is injected into the anterior chamber to the treatment of endothelial decompensation in complex preoperative unfold and then push the graft against the posterior surface of situations. the corneal stroma. The performance of the air bubble during surgery is largely influenced by an absent lens or vitreous Key Words: Descemet membrane endothelial keratoplasty, irido- support (vitrectomized eyes). In aphakic eyes, the air bubble corneo-endothelial syndrome, aphakia, subluxation of intraocular tends to move through the pupil into the posterior chamber lens causing the iris to move forward. Furthermore, the thin rolled (Cornea 2015;34:1351–1357) graft might dislocate through the pupil into the posterior chamber during surgery as described for DSAEK in aphakic 6 Received for publication May 19, 2015; revision received July 26, 2015; or vitrectomized eyes. Similarly, the performance of the accepted August 3, 2015. Published online ahead of print September 18, bubble is changed by injecting fluid into the vitreous during 2015. administration of antiangiogenic drugs for the treatment of From the Department of Ophthalmology, Friedrich-Alexander University cystoid macular edema. The resulting increase in vitreous Erlangen-Nuremberg, Erlangen, Germany. The authors have no funding or conflicts of interest to disclose. pressure decreases the anterior chamber, both increasing the Supplemental digital content is available for this article. Direct URL citations risk for pupillary block and reducing the size of the air appear in the printed text and are provided in the HTML and PDF bubble, which can be safely administered during surgery. versions of this article on the journal’s Web site (www.corneajrnl.com). Thereby, the risk of postoperative graft detachment might be Reprints: Julia M. Weller, MD, Department of Ophthalmology, University of fl Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany increased. After trabeculectomy, anterior chamber uidics are (e-mail: [email protected]). altered and might influence anterior chamber stability and Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. unfolding of the graft during DMEK.

Cornea Volume 34, Number 11, November 2015 www.corneajrnl.com | 1351

Therefore, we wondered whether DMEK is technically in the cartridge. During insertion of the graft, the anterior possible and successful in endothelial decompensation and chamber was stabilized with an irrigation handpiece. The complex preoperative situations, as there are: graft was unrolled by insertion of a small air bubble inside the roll and lateral movements of the bubble by gentle pressure 1. eyes with a shallow anterior chamber with anterior on the cornea. After complete unrolling of the graft, the air synechiae in irido-corneo-endothelial (ICE) syndrome bubble, which had been inside the graft roll, was replaced by – 2. eyes with altered iris lens diaphragm [aphakia/sub- an air bubble between the graft and iris to allow graft luxation of a posterior chamber intraocular lens (PC attachment. IOL)/anterior chamber intraocular lens (AC IOL)] DMEK with simultaneous phacoemulsification and 3. eyes after previous trabeculectomy with antimetabolite implantation of a posterior chamber IOL (triple procedure) treatment was performed in 3 eyes (patients 2, 3, and 16). At the end of 4. eyes with cystoid macular edema requiring simulta- the procedure, the anterior chamber was filled with an air neous intravitreal vascular endothelial growth factor bubble, which was reduced to 50% of the anterior chamber (VEGF) antagonists volume after 60 minutes. If graft detachment with delayed 5. eyes after previous vitrectomy. corneal clearing was detected postoperatively at slit-lamp In this study, we present the results of DMEK in 24 examination or by slit-lamp optical coherence tomography, eyes with complex preoperative situations. rebubbling with installation of an air bubble into the anterior chamber was performed. All group 2 patients underwent a 2-step procedure. In MATERIALS AND METHODS case of aphakia, the first surgery was the implantation of a scleral-sutured PC IOL (Morcher 81 B; Morcher GmbH, Patients Stuttgart, Germany). In pseudophakic eyes with IOL sub- In this retrospective study, patients undergoing DMEK luxation or AC IOLs, the IOL was explanted and replaced by for the treatment of endothelial decompensation in complex a scleral-sutured PC IOL (n = 3) or the existing IOL was preoperative situations were included. Of a total of 1184 reimplanted with scleral suture-fixation (n = 1). If necessary, DMEK surgeries, which had been performed between further surgical steps were performed, such as suture of the September 2009 and September 2014, 24 eyes of 24 patients iris for pupilloplasty (n = 1) or anterior vitrectomy (n = 3). In fulfilled the following inclusion criteria: group 1: ICE a second step, DMEK was performed after stabilization of the syndrome (n = 3); group 2: aphakia, AC IOL, or subluxation iris–lens diaphragm. Because vitreous support is still func- of a PC IOL (n = 6); group 3: DMEK after trabeculectomy tional after anterior vitrectomy through corneal incisions, we with or without antimetabolite treatment (n = 4); group 4: did not combine these eyes with group 5 (vitrectomy group). DMEK with simultaneous intravitreal injection for cystoid Patients in group 4 received an intravitreal injection of macular edema (n = 6); and group 5: DMEK after vitrectomy bevacizumab (1.0 mg in 0.2 mL) or ranibizumab (0.3 mg in (n = 5). Indication for DMEK was endothelial decompensa- 0.05 mL) upon completion of DMEK surgery. tion due to Fuchs endothelial dystrophy (n = 10), ICE The time of surgery was 30 6 6 minutes. The slightly syndrome (n = 3), and pseudophakic/aphakic bullous kerat- prolonged surgery time, compared with that of standard opathy (n = 11). Patient characteristics and a detailed list of DMEK procedures, was because of the following reasons: indications for DMEK are shown in Supplemental Digital removal of irido-corneal adhesions (n = 4), removal of the Content (see Table 1, http://links.lww.com/ICO/A355). corneal epithelium because of poor visibility of the anterior Of the patients, 11 (46%) were male and 13 (54%) were chamber (n = 5), removal of a retrocorneal membrane (n = 1), female. Mean age at the time of surgery was 69 6 10 years corneoscleral sutures (n = 5) because of an untight tunnel (range 49–90 years). All DMEK surgeries were performed incision, and suture of an untight paracentesis (n = 1). between September 2009 and September 2014 by 2 experi- Intraoperative complications included difficult descemeto- enced surgeons. Mean follow-up duration was 10 months rhexis because of strong adhesion of the recipient’s Descemet (range 1–53 months). membrane (patient 8), slight decentration of the graft because The study complied with the tenets of the Declaration of a very deep anterior chamber after a scleral-sutured IOL of Helsinki and adhered to all state laws of the country. The (patient 9), repeat collapse of the anterior chamber because of Institutional Review Board of the University of Erlangen- an untight tunnel incision (patient 10), very difficult graft Nuremberg, Germany, waived the need for approval. unfolding because of a flat anterior chamber (patient 14).

Surgical Technique Clinical Evaluation Graft preparation and graft transplantation for DMEK The primary outcome parameter was success of were performed as previously described in detail.7 After surgery. The parameters analyzed in this study included stripping of the donor’s Descemet membrane using the 2- best-corrected visual acuity (BCVA), central corneal thick- forceps technique, the graft roll was transferred into the ness (CCT) (Pentacam; Oculus, Wetzlar, Germany), endo- cartridge of an IOL shooter (Acri.Tec GmbH, Hennigsdorf, thelial cell density (ECD) (SeaEagle; RHINE-TEC GmbH, Germany). To maintain correct orientation of the graft roll, Krefeld, Germany), and graft failure. The need for additional a small air bubble was placed into the lumen of the roll while intracameral air injections (rebubblings) after DMEK was

assessed at slit-lamp examination and by the use of slit-lamp Group 2: Aphakia/IOL Subluxation/AC IOL optical coherence tomography (Heidelberg Engineering, After stabilization of the iris–lens diaphragm by Heidelberg, Germany). Examination results from the day implantation of a scleral-sutured PC IOL in eyes with aphakia before DMEK and from 1, 3, and 6 months after grafting (n = 2), IOL subluxation (n = 2), or an AC IOL (n = 2), were evaluated. DMEK was performed after an average interval of 5 6 4 months (range 2–14 months). Graft detachment requiring rebubbling occurred in 4 eyes; there was no graft failure. Statistical Analysis BCVA increased in all patients. In 1 patient with an AC IOL Statistical evaluation was performed using IBM SPSS (patient 9), the interval between IOL exchange and DMEK software version 20.0 (SPSS, Armonk, NY). Differences of was 14 months; he needed 4 intravitreal applications of parameter values within groups were assessed using the bevacizumab after IOL exchange because of recurrent cystoid Wilcoxon test. P values are shown for the comparison macular edema. After successful DMEK, no recurrence of between visit 0 and 1, 1 and 3, and 3 and 6, respectively. cystoid macular edema has been observed. Figure 2 shows The signiﬁcance level was set at P = 0.05. exemplary clinical pictures of a patient with aphakia.

RESULTS Group 3: Previous Trabeculectomy The DMEK procedure was technically feasible in all 24 DMEK was performed in 4 eyes that had undergone eyes. There was no primary graft failure. Eight eyes with trabeculectomy for glaucoma 1 to 18 years ago. Rebubbling severe ocular comorbidities inﬂuencing visual acuity was necessary in 2 eyes; secondary graft failure occurred in 3 (advanced glaucoma, macular degeneration, previous retinal of 4 eyes (patients 10, 11, and 13) after 6, 8, and 18 months, detachment and macular pucker, amblyopia) were excluded respectively. Graft failure was treated by secondary DMEK from analysis of BCVA. (n = 1) or perforating keratoplasty (n = 1). No regrafting is With respect to all eyes (including eyes with ocular planned in 1 patient (patient 10), despite graft failure, because comorbidities), 20/24 had improved BCVA. Two eyes with visual prognosis in advanced glaucoma is limited. ocular comorbidities or graft failure had stable BCVA, and 2 eyes with graft failure had worse BCVA after DMEK. In eyes without ocular comorbidities, BCVA (logMAR) Group 4: Simultaneous Intravitreal increased from 0.98 6 0.37 to 0.53 6 0.30 (P = 0.002), Application of VEGF Antagonists for Cystoid 0.53 6 0.49 (P = 0.091), and 0.57 6 0.52 (P = 0.203) after 1, Macular Edema 3, and 6 months, respectively (Fig. 1A). Regarding only eyes DMEK with simultaneous intravitreal application of without graft failure or ocular comorbidities, the BCVA bevacizumab or ranibizumab for cystoid macular edema was increased from 0.89 6 0.31 to 0.50 6 0.23 (P = 0.007), performed in 6 eyes. Indication for keratoplasty was Fuchs 0.46 6 0.27 (P = 0.017), and 0.36 6 0.18 (P = 0.684) after 1, endothelial dystrophy (n = 3) or pseudophakic bullous 3, and 6 months, respectively. keratopathy (n = 3). Etiology of cystoid macular edema was CCT decreased from 731 6 170 to 546 6 152 mm(P = age-related macular degeneration (n = 1), previous cataract 0.001), 514 6 66 mm(P = 0.932), and 554 6 98 mm(P = surgery (n = 2), and previous DMEK (n = 3). Five patients 0.004) after 1, 3, and 6 months, respectively (Fig. 1B). ECD were treated with simultaneous intravitreal bevacizumab decreased from 2478 6 185/mm2 in donor corneas before injection, and 1 patient with simultaneous intravitreal ranibi- DMEK to 1454 6 193/mm2 (P , 0.001), 1301 6 298/mm2 zumab injection. There was 1 graft failure after DMEK with (P = 0.241), and 1374 6 261/mm2 (P = 0.213) in recipients simultaneous intravitreal injection of VEGF antagonists after 1, 3, and 6 months, respectively (Fig. 1C). (patient 17). Rebubbling was necessary in 2 eyes. Recurrence Rebubblings due to graft detachment in the early of cystoid macular edema was observed in 1 patient 3 months postoperative period were necessary in 11 of 24 eyes (46%) after DMEK with simultaneous bevacizumab injection (1 rebubbling in 9 eyes and 2 rebubblings in 2 eyes). Four (patient 19). Postoperative loss of endothelial cells did not patients (17%) had secondary graft failure between 6 and 18 differ signiﬁcantly in group 4 compared with the other eyes. months after DMEK (mean 10 months). The highest rate of In group 4, ECD was 2437 6 197/mm2 in the graft before graft failure was found in group 3 (n = 3, 75%). surgery and decreased to 1442 6 137/mm2, 1284 6 211/ mm2, and 1345 6 256/mm2 after 1, 3, and 6 months, respectively (P . 0.05 between group 4 and other eyes at Group 1: ICE Syndrome each visit). DMEK was performed in 3 eyes with ICE syndrome (n = 3). The eyes were characterized by anterior synechiae causing partial closure of the chamber angle, corectopia, and Group 5: Previous Vitrectomy a shallow anterior chamber. DMEK was successful in all eyes Five patients undergoing DMEK had previous pars with an increase in BCVA and reduction in CCT. DMEK was plana vitrectomy because of macular pucker (n = 2), combined with synechiolysis in 2 eyes with ICE syndrome. endophthalmitis (n = 1), and rhegmatogenous retinal detach- Rebubbling was necessary in 2 eyes (patients 2 and 3), no ment (n = 2). Indication for DMEK was corneal edema in graft failure occurred. Fuchs endothelial dystrophy in all eyes. The median interval

FIGURE 1. Outcome after DMEK. A, Box plot showing BCVA in eyes without ocular comorbidities (n = 16) before DMEK (BCVA preop) and 1, 3, and 6 months after DMEK, respectively. The difference between BCVA before DMEK and 1 month after DMEK is statistically signiﬁcant (P = 0.002). B, Box plot showing CCT before DMEK (CCT preop) and 1 (P = 0.001), 3 (P = 0.932), and 6 months (P = 0.004) after DMEK, respectively. Eyes with secondary graft failure are included. C, Box plot showing ECD before DMEK (ECD preop) and 1, 3, and 6 months after DMEK, respectively. Eyes with secondary graft failure are included. The difference between ECD before DMEK and 1 month after DMEK is statistically signiﬁcant (P , 0.001).

between vitrectomy and DMEK was 3 years (range 1–6 our patients.8 The difference might be explained by technical years). There were no intraoperative complications. Graft issues; the main challenge of DMEK in eyes with ICE detachment requiring rebubbling occurred in 1 eye, no graft syndrome is the shallow anterior chamber with peripheral failure occurred. anterior synechiae, which makes graft unfolding more difﬁcult. This also results in more frequent graft detachments. According to our experience, it is important that the graft DISCUSSION diameter is chosen according to the free retrocorneal surface, The results of this study indicate that DMEK is which depends on the extent of the synechiae. Thus, grafts a suitable procedure for treatment of eyes with endothelial tend to be much smaller than in, for example, Fuchs decompensation and complex intraocular comorbidity. To endothelial corneal dystrophy. Handling of DSAEK grafts date, there are few case reports dealing with DSAEK in ICE within the anterior chamber is easier than unrolling and syndrome, and none deals with DMEK in ICE syndrome.8,9 positioning of DMEK grafts. Therefore, DSAEK might still Compared with our series, Price and al reported better be advantageous in eyes with a narrow anterior chamber and postoperative BCVA after DSAEK in ICE syndrome, but iris adhesions. Larger cohorts of patients are necessary to the patients in this series had better preoperative BCVA than compare DMEK with DSAEK in ICE syndrome.

confronted with a nonexisting or unstable iris–lens diaphragm, which causes the risk of dropping the graft into the vitreous during DSAEK, as described in several case reports.6 Such complications often result in poor clinical outcomes. Because DMEK grafts are thinner than DSAEK grafts, the risk of graft dislocation in DMEK is higher. In addition, the DSAEK graft is pulled into the eye with forceps while the thin DMEK graft is injected into the anterior chamber. A 2- step approach with initial stabilization of the iris–lens diaphragm and secondary DMEK has been previously described for DSAEK in aniridic/aphakic eyes.11 Neverthe- less, endothelial keratoplasty is difficult in these eyes because the air bubble tends to move behind the iris and scleral- sutured IOL or artificial iris implant making attachment of the graft difficult.11 An alternative to the 2-step approach in aniridic or aphakic eyes has been described in DSAEK.12 Dislocation of a DSAEK lenticle can be prevented in aphakic eyes by anchoring sutures to fixate the graft transcorneally. However, this technique is not possible in DMEK, because in DMEK the graft is usually injected with an IOL cartridge into the anterior chamber, and the graft roll is too thin to be fixated safely with a suture. To avoid the complication of graft dislocation, we prefer the 2-step approach with initial stabilization of the iris– lens diaphragm and secondary DMEK. If visibility of the intraocular structures is reduced because of advanced corneal edema, the reestablishment of the iris–lens diaphragm might be difficult. In these eyes, we improve the visibility by debriding the corneal epithelium or deswelling of the cornea with hyperosmolar agents. The management of eyes with corneal decompensation after the implantation of an AC IOL has been discussed controversially. Hsu et al10 recommend removal of AC IOLs only if the IOL is contributing to corneal edema or glaucoma or if the anterior chamber is shallow. Esquenazi et al13 advised against removal of AC IOLs before DSAEK because the observed decrease of ECD was only 24% in the first year in cases with retained AC IOLs. According to Liarakos et al,14 DMEK is feasible in eyes with AC IOLs left in situ. They recommend removal of AC IOLs only in the case of anticipated postoperative complications, for example, in preexistent glaucoma, or if the AC IOL has been responsible for endothelial decompensation by contact between the IOL and endothelium. In contrast, Khor et al recommend lens exchange from FIGURE 2. DMEK in aphakic eyes. A 79-year-old woman fi (patient 4) presented with aphakia, corneal edema, sectorial AC IOLs to posteriorly xated IOLs in all eyes with AC IOLs iris defect, peripheral anterior synechiae, and cystoid macular before endothelial keratoplasty. They observed higher graft edema after complicated cataract surgery 5 months ago (A). failure rates in eyes undergoing DSAEK with retained AC Three months after implantation of a scleral-sutured PC IOL IOLs.15 DMEK with simultaneous secondary iris-fixated IOL (B), DMEK was performed with simultaneous suture of the iris implantation has been described recently in a small case series.16 to narrow the pupil (C). BCVA (logMAR) increased from 0.8 to In an analysis of DSAEK in 30 complex eyes with 0.6 and 0.4 after 1 and 3 months, respectively. aphakia or AC IOLs, Hsu et al10 found a graft detachment rate of 16.7% (group 2 in our study: 4/6) and a graft failure rate of 10% (group 2 in our study: 0/6). However, the study cohorts Aphakia or complex IOL situations (AC IOL or are small and inhomogenous and cannot be compared directly. subluxated IOL) are challenging situations for corneal sur- Because graft unrolling and attachment is more difficult in geons. The visual outcome after DSAEK in these patients is DMEK compared with DSAEK, we prefer IOL exchange from worse than in patients with an IOL in the bag.10 Surgeons are AC IOLs to scleral-sutured PC IOLs in eyes, and secondary

DMEK. An advantage of either DSAEK or DMEK in this the results in the subgroup of vitrectomized eyes. Eguchi et al25 subgroup cannot be deduced from the available data. described their technique for DSAEK in 2 vitrectomized eyes A small case series with 4 patients with previous with a postoperative BCVA of 20/50 and 20/320, respectively. trabeculectomy or glaucoma shunt undergoing DSAEK In a prospective study with 136 eyes, Guerra et al26 showed positive results regarding the outcome of DSAEK, as reported that DMEK was performed with simultaneous pars well as postoperative intraocular pressure values.17 The authors plana vitrectomy in 3 eyes, but they did not publish the recommend a smaller graft diameter than usual to avoid contact clinical outcome of this subgroup in detail. Yoeruek et al27 with the glaucoma tube and prolonged air filling. Another described a high rate of intraoperative and postoperative report about DSAEK after trabeculectomy or tube shunt complications in DMEK in 20 vitrectomized eyes. They surgery described an increased rate of intraoperative compli- recommended the use of an infusion cannula through the pars cations (eg, damage to the graft), but good postoperative plana to stabilize the posterior segment, thereby enabling outcomes.18 In a recent study, Nahum et al19 analyzed 1033 adherence of the graft. eyes undergoing DSAEK. They found that previous trabecu- In our study, DMEK in 5 eyes with previous vitrectomy lectomy is associated with a significantly higher graft failure was analyzed. The intraoperative course and outcome of rate after DSAEK. Ni et al20 assessed outcomes of DSAEK in DMEK in this group were good, but the increase in BCVA eyes with glaucoma drainage devices and found a graft failure was limited by retinal pathologies in 3 patients. rate of 29%. Endothelial cell loss was 75% by month 18. In conclusion, this study provides evidence that DMEK Price et al21 described late endothelial failure in 1 eye is feasible in eyes with complex preoperative situations such with trabeculectomy before DMEK. In our study, 4 eyes with as ICE syndrome, unstable iris–lens diaphragm, previous previous trabeculectomy were included. The intraoperative vitrectomy, previous trabeculectomy, or combined with intra- course was uneventful. However, 3 of 4 eyes developed vitreal VEGF antagonists. Compared with DMEK under secondary graft failure after 6, 8, and 18 months, respectively. standard circumstances, the outcome regarding BCVA, There was no decompensation of intraocular pressure or bleb rebubbling rate, and graft failure rate was worse.2 Especially scarring after surgery in our study. Possible explanations for in eyes with previous trabeculectomy, the graft failure rate the high rate of graft failure (75%) in this group are (1) altered was high (75%). Therefore, the use of DMEK after trabecu- fluidics in the anterior chamber with possible turbulence lectomy remains controversial. Further studies with larger making the unrolling of the graft difficult, (2) fast absorption patient cohorts are desirable to determine whether DMEK is of the air bubble/escape through the filtering bleb leading to advantageous for the treatment of endothelial failure in all decreased pressure against the corneal stroma, or (3) hypot- eyes with difficult preoperative situations. ony after surgery increasing the risk of graft detachment. According to the results of our study, DMEK after trabeculectomy cannot be recommended unrestrictedly because REFERENCES of the very high graft failure rate. However, larger studies are 1. Melles GR, Ong TS, Ververs B, et al. 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