Descemet Membrane Endothelial Keratoplasty versus Descemet Stripping Automated Endothelial Keratoplasty in Complicated Vitrectomized Eyes

Retinal Detachment Rates After Uncomplicated DMEK Versus Cataract Surgery Combined (Triple-)DMEK

PURPOSE

To evaluate the rate of and risk factors for rhegmatogenous retinal detachment (RRD) after Descemet membrane endothelial keratoplasty (DMEK) either alone or in combination with cataract surgery.

DESIGN

Retrospective analysis of prospective database.

METHODS

Consecutive eyes with Fuchs endothelial corneal dystrophy (FECD) that received DMEK surgery with a minimum follow-up of 1 year between July 2011 and January 2021 at the Department of Ophthalmology at the University of Cologne were analyzed. Exclusion criteria were complicated history including repeat DMEK within 1-year, previous retinal or glaucoma surgery, complicated phacoemulsification, congenital cataract, history of trauma.

RESULTS

From 3858 consecutive DMEKs, 1961 patients were identified suitable for analysis. 846 (43.1%) were pseudophakic DMEK, 91 (4.6%) phakic DMEK and 1,024 (52.2%) combined with cataract surgery. RRD occurred in 13 eyes (12 patients). Within two years after DMEK RRD occurred in 0.49% and 0.47% after DMEK and DMEK with cataract surgery, respectively. Mean age of 59.24 ± 8.42 years with subsequent RRD was significantly lower than overall 68.81 ± 9.89 years (t-test two-tailed; p < 0.001). The spherical equivalent was -4.69 ± 3.98 D (range -9.00 to 0.5) in RRD after pseudophakic DMEK compared to -2.79 ± 3.54 D (range -7.5 to 0.75) in combined procedures. Re-bubbling had no influence on RRD rate.

CONCLUSIONS

DMEK alone or in combination with cataract surgery showed similar postoperative RRD rates in the first two years, generally in the range of pseudophakic RRDs. Risk factors such as myopia and younger age could be identified. Re-bubbling has no influence on RRD rates.

Effect of Anterior Chamber Air on Central Corneal Thickness in Human Donor Eyes

PURPOSE

The purpose of this study was to describe the effects of intracameral air on corneal edema.

METHODS

A laboratory investigation was performed on human donor corneas. Baseline pachymetry measurements through anterior segment optical coherence tomography and endothelial cell density were obtained for all corneas. Each pair of corneas was separated and randomly assigned to undergo air injection or Optisol-GS into a BIONIKO artificial anterior chamber for 5 minutes at physiologic intraocular pressure confirmed by digital palpation. Photographs were obtained immediately on connection of the cornea to the artificial anterior chamber and on completion of the 5 minutes of treatment, with anterior chamber air being exchanged for Optisol-GS. Pretreatment and posttreatment photographs were obtained. Immediately after treatment, pachymetry was again obtained on all corneas. Pachymetry data underwent statistical analysis.

RESULTS

Corneal pachymetry improved from 690.5 ± 126.6 to 576.1 ± 87.2 μm, yielding a 114.4 ± 50.4 μm improvement of pachymetry in the group with air injected into the anterior chamber. This was a significant improvement of pachymetry when compared with the group with Optisol-GS injected into the anterior chamber, which showed an improvement from 662.3 ± 126.5 to 613.5 ± 108.0 μm, yielding an improvement of 48.8 ± 34.3 μm.

CONCLUSIONS

Injection of air into the anterior chamber leads to a significant decrease in corneal pachymetry. We thereby propose that injecting air intracamerally is an effective intraoperative intervention when visualization is negatively affected by corneal edema.

Pull-through insertion of EndoArt for complex eyes

Purpose

To report an alternative technique to implant the EndoArt using a pull-through insertion. This technique is helpful in complex eyes, especially in eyes with unstable iris lens diaphragm.

Observation

We present a case of advanced pseudophakic bullous keratopathy with aniridia, previous vitrectomy, and tube implants in which the initial attempt to implant the EndoArt failed, and the device was lost to the vitreous cavity. An alternative surgical technique, a pull-through insertion, was used to implant a second device successfully. The patient was followed over a period of 1 year. Corneal edema gradually improved over time, and all epithelial bullae resolved. The central corneal thickness (CCT) decreased from 911um to 691 μm.

Conclusion and Importance

EndoArt is a treatment for endothelial failure in complex eyes. In addition, the pull-through insertion technique can help improve control over the implant in very complicated eyes.

Clinical Outcomes of Transscleral-Sutured Intraocular Lens Combined With Descemet Membrane Endothelial Keratoplasty

PURPOSE

The aim of the study was to report clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) combined with transscleral-sutured intraocular lens (IOL) compared with DMEK combined with phacoemulsification and posterior chamber IOL (Phaco-DMEK).

METHODS

A retrospective chart review of all patients who underwent DMEK combined with transscleral-sutured intraocular lens fixation or combined with phacoemulsification for Fuchs endothelial corneal dystrophy from 2016 to 2021 at the Toronto Western Hospital or the Kensington Eye Institute (Toronto, ON, Canada) and had at least 18 months of follow-up was performed. Main outcomes were postoperative distance-corrected visual acuity, rebubbling rate, graft survival rate, and complications.

RESULTS

Twenty-one cases of DMEK combined with transscleral-sutured IOL (DMEK-TSS-IOL) and 44 cases of Phaco-DMEK were evaluated. Twelve eyes (57.15%) had a foldable acrylic 3-piece IOL (AR40E) and 9 (42.85%) had a single-piece polymethylmethacrylate (PMMA) IOL (CZ70BD). LogMAR distance-corrected visual acuity improved significantly from 1.48 ± 0.62 (SD) to 0.86 ± 0.82 ( P = 0.01) 12 months after DMEK-TSS-IOL and from 0.41 ± 0.29 logMAR to 0.11 ± 0.11 logMAR ( P < 0.0001) after Phaco-DMEK. No statistically significant differences were observed in donor ( P = 0.97) or 1-year postoperative endothelial cell density ( P = 0.11) between the groups. Rebubbling was necessary in 33.33% of eyes in DMEK-TSS-IOL compared with 25% of Phaco-DMEK eyes ( P = 0.55). Graft survival rate was 76.19% in the DMEK-TSS-IOL group compared with 90.90% in the Phaco-DMEK group ( P = 0.13).

CONCLUSIONS

Transscleral-sutured IOL combined with DMEK is an option for the management of endothelial diseases in aphakic eyes or those which require IOL exchange for the experienced surgeon. However, when compared with routine Phaco-DMEK, there are higher complication and lower survival rates at 18 months.

Descemet membrane endothelial keratoplasty compared with ultrathin Descemet stripping automated endothelial keratoplasty: a meta-analysis

AIMS

This study aims to compare the clinical outcome of Descemet membrane endothelial keratoplasty (DMEK) and ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) in patients with corneal endothelial dysfunction due to Fuchs' endothelial dystrophy or pseudophakic bullous keratopathy.

METHODS

We conducted a meta-analysis using a literature search of Embase, PubMed, Cochrane CENTRAL, ClinicalTrials.gov and WHO ICTRP databases. We included randomised controlled trials (RCTs) and cohort studies that compared DMEK and UT-DSAEK (graft<130 µm), with a follow-up of ≥12 months, published until 20 February 2022. We used the Revised Cochrane risk-of-bias tool for RCTs and the Risk of Bias in Non-Randomised Studies-of Interventions system for cohort studies.

RESULTS

Out of 144 records, 8 studies (3 RCTs, 2 fellow-eye studies and 3 cohort studies) were included, encompassing 376 eyes, (N=187 DMEK vs N=189 UT-DSAEK). The 12-month logarithm of the minimum angle of resolution best-corrected visual acuity (BCVA) was better post-DMEK (mean difference -0.06 (95% CI -0.10 to -0.02)), but with higher rebubbling risk: OR 2.76 (95% CI 1.46 to 5.22). Heterogeneity was significant I2=57%. Findings were consistent when excluding retrospective studies, including only studies with low risk of bias or RCTs only. An analysis of studies with mean DSAEK grafts <70 µm showed no significant difference in BCVA between the procedures. Publication bias was found in the BCVA analysis (Egger's test p=0.023).

CONCLUSIONS

Post-DMEK BCVA is superior to post-UT-DSAEK when using <130 µm grafts. DSAEK grafts <70 µm may not significantly differ from DMEK. The higher risk of rebubbling with DMEK necessitates an appropriate selection of patients.

PROSPERO REGISTRATION NUMBER

CRD42022340805.

Descemet Membrane Endothelial Keratoplasty and Triple Descemet Membrane Endothelial Keratoplasty in Eyes With Macular Comorbidity

PURPOSE

The aim of this study was to evaluate results after Descemet membrane endothelial keratoplasty (DMEK) and DMEK with cataract surgery (triple DMEK) in eyes with endothelial dysfunction and concomitant macular pathology.

METHODS

A monocentric, prospective clinical observational study of patients who underwent DMEK or triple DMEK surgery at the Department of Ophthalmology, University Hospital Düsseldorf, Germany, from June 2013 to February 2016 was conducted. Sex, age, best-corrected visual acuity (BCVA), central corneal thickness, endothelial cell density, and central retinal thickness in the 1 millimeter zone were analyzed.

RESULTS

A total of 209 eyes were included in the study. Forty-two eyes (20.1%) had vision-limiting concomitant maculopathies. These were age-related macular degeneration (n = 17, 8.1%), epiretinal gliosis (n = 13, 6.2%), chronic macular edema (n = 7, 3.3%), macular holes (n = 3, 1.4%), and macular scarring (n = 2, 1.0%). BCVA significantly increased in patients without maculopathy from 0.6 ± 0.33 logMAR to 0.1 ± 0.15 logMAR ( P < 0.001) and also in patients with maculopathy from 0.9 ± 0.38 logMAR to 0.27 ± 0.23 logMAR 12 months postoperatively ( P < 0.001). There was a significant central retinal thickness increase of 34.1 μm 6 weeks after triple DMEK in the central 1-mm zone ( P = 0.011). This increase was insignificant after DMEK. Postoperative macular edema occurred in 5.9% of cases after DMEK and 8.1% after triple DMEK, which was not significantly different.

CONCLUSIONS

DMEK and triple DMEK significantly increase BCVA in eyes with concomitant maculopathy. Postoperative macular edema is a common disorder after lamellar keratoplasty; therefore, prophylactic treatment with nonsteroidal antiinflammatory drugs should be considered. Maculopathies did not predispose the development of postoperative macular edema.

Systematic Review and Meta-analysis: Outcomes After Descemet Membrane Endothelial Keratoplasty Versus Ultrathin Descemet Stripping Automated Endothelial Keratoplasty

PURPOSE

To compare the efficacy and safety of ultrathin Descemet stripping (automated) endothelial keratoplasty (UT-DS(A)EK) versus Descemet membrane endothelial keratoplasty (DMEK) for the treatment of Fuchs endothelial dystrophy (FED) and bullous keratopathy (BK).

DESIGN

Systematic review and meta-analysis.

METHODS

Literature containing DMEK and UT-DSAEK were searched in the Cochrane Database of Systematic Reviews, PubMed, EMBASE, LILACS, and through manual reference searching. Studies were included that measured the outcome of interventions-including best corrected visual acuity (BCVA), endothelial cell density (ECD), and postoperative complications, especially graft detachment with the need of re-bubbling, graft rejection, graft failure, and postoperative elevated intraocular pressure (IOP)-in patients with FED and BK. Included outcomes were pooled as standardized mean differences (SMD) or risk ratios (RR) using random effects models. Inter-study heterogeneity was assessed using the Q-test and I2 statistic.

RESULTS

Seven (of 163) studies met all the inclusion and exclusion criteria. Meta-analysis showed a significantly better BCVA 12 months postoperatively, but an increased re-bubbling rate in eyes after DMEK compared with eyes after UT-DS(A)EK (BCVA: SMD = 0.50 [95% CI 0.27-0.74] and re-bubbling rate: RR = 0.33 [95% CI 0.16-0.67]). All other parameters did not differ significantly between both interventions, although estimates were imprecise (graft failure: RR = 0.65 [95% CI 0.18-2.30], graft rejection: RR = 1.40 [95% CI 0.27-7.30], and postoperative intraocular pressure elevation: RR = 1.14 [95% CI 0.60-2.18]). Postoperative SMDs of ECD could not be evaluated due to significant heterogeneity between studies.

CONCLUSIONS

Although the improvement in BCVA was higher after UT-DS(A)EK than after conventional DS(A)EK, the BCVA after DMEK was still superior. The complication rates were comparable for both procedures, except for the higher rate of re-bubbling after DMEK.

Descemet membrane endothelial keratoplasty in complex eyes

PURPOSE OF REVIEW

To review the current literature on Descemet membrane endothelial keratoplasty (DMEK) in complex eyes.

RECENT FINDINGS

DMEK surgery has become a standardized procedure in Fuchs endothelial dystrophy and simple bullous keratopathy. But eyes with more complex disease present unique intraoperative and postoperative challenges to the DMEK surgeon. Poor visualization during surgery, complex anterior segment anatomy, altered anterior chamber dynamics, glaucoma shunts, and congenital or iatrogenic missing or altered iris and lens make DMEK surgery extremely difficult to accomplish.

SUMMARY

DMEK is feasible in complex eyes, including advanced bullous keratopathy, eyes with history of glaucoma or vitreoretinal surgery, previous penetrating keratoplasty, uveitis, pediatric, and congenital anterior segment disorders. The tools and methods reported in the literature to accomplish DMEK in complex eyes vary widely with no particular consensus or standardization of techniques. The outcomes noted for some of these conditions demonstrate the difficulty of the surgery and the uncertainty of long-term graft survival in complex eyes. Both surgical standardization and randomized prospective data will better help elucidate DMEK's role in the corneal rehabilitation of complex eyes.