Identifying causes for poor visual outcome after DSEK/DSAEK following secondary DMEK in the same eye

Purpose: To identify causes of reduced visual acuity after Descemet stripping (automated) endothelial keratoplasty (DSEK/DSAEK) and to determine whether such eyes can be successfully ‘repaired’ with a secondary Descemet membrane endothelial keratoplasty (DMEK). Methods: Twelve eyes of 12 patients, who underwent secondary DMEK to manage poor visual outcome after initial DSEK/DSAEK, were evaluated with biomicroscopy, Pentacam imaging, and specular and confocal microscopy, before and at 1, 3 and 6 months after DMEK. Results: Four causes of reduced optical quality of the transplanted host cornea could be identified in DSEK/DSAEK: five eyes (42%) showed large host‐Descemet remnants within the visual axis during surgery; six eyes (50%) irregular graft thickness; six eyes subtle ‘stromal waves’; and nine eyes (75%) high reflectivity at the donor‐to‐host interface. After DMEK graft replacement, all corneas cleared and achieved a best corrected visual acuity of ≥20/25 (≥0.8), except for one with a partial Descemet graft detachment. Pachymetry values decreased from 670 (±112) μm before to 517 (±57) μm after secondary DMEK. Higher‐order aberrations (Coma and Trefoil) at the posterior surface tended to be lower (p = 0.07) in DMEK grafts than in DSEK/DSAEK grafts. Conclusion: Host‐Descemet remnants at the donor‐to‐host interface, interface reflectivity, graft thickness irregularity and donor stromal contraction may contribute to poor visual outcome after DSEK/DSAEK, without causing permanent host corneal damage, as in most cases, complete visual recovery could be achieved by performing a secondary DMEK.     

自动板层刀辅助的后弹力层前膜角膜内皮移植术

角膜内皮移植已成为治疗角膜内皮病变的首选方法.作为目前主流的2种角膜内皮移植手术——后弹力层剥除自动板层刀制备的角膜内皮移植术和后弹力层角膜内皮移植术,前者手术操作易于掌握,但角膜植片仍带有部分基质;后者术后视觉质量好,但手术操作较难掌握,二次手术率较前者高.大气泡和自动板层刀辅助的后弹力层前膜角膜内皮移植术在自动板层刀制备角膜内皮植片的基础上,用大气泡法暴露中央6.5 mm直径的后弹力层前膜,本术式既有后弹力层角膜内皮移植术后的视觉效果,手术操作又易于掌握,值得推广.     

角膜后弹力膜内皮移植术研究进展

角膜后弹力膜内皮移植术由于具有相对较低的移植排斥率以及较好的视力预后等优势,目前已成为部分发达国家治疗角膜内皮失代偿的主流手术方式,但限于手术难度较高,学习曲线较长,中国人前房偏浅,加之国内角膜内皮病变往往合并有其他较复杂的眼部疾病,目前国内尚未普遍开展这一手术。本文就角膜后弹力膜内皮移植术的手术适应证、供体植片制备(...     

Descemet stripping and automated endothelial keratoplasty: an alternative to penetrating keratoplasty.

PURPOSE: To discuss Descemet stripping and automated endothelial keratoplasty (DSAEK) as an alternative to penetrating keratoplasty (PK), and to review the evolution of endothelial keratoplasty (EK) for endothelial dysfunction. METHODS: The endothelium of the right eye was removed through a 5-mm limbal incision and was replaced with a prepared donor endothelium that included posterior stromal tissue. RESULTS: After DSAEK, the patient's vision improved more rapidly and remained more stable than is typical for patients undergoing PK. CONCLUSION: DSAEK provides an alternative both to PK and to a repeat PK in patients with failed grafts because of endothelial cell dysfunction. The advantages DSAEK surgery can offer are a quicker visual recovery, a more stable refraction, a tectonically more stable globe, and fewer ocular surface defects associated with corneal sutures or the surface graft host interface. The limitations associated with DSAEK include donor button dislocation and endothelial cell loss and dysfunction. Whether DSAEK or PK offers the best visual outcome and graft survival over the long term is unknown. Caution is advised until multicenter trials confirm the optimal procedure.     

Two-year clinical outcome after Descemet membrane endothelial keratoplasty using a standardized protocol

Purpose:The purpose of this study is to evaluate 2-year clinical outcome after Descemet membrane endothelial keratoplasty (DMEK) in a variety of endothelial dysfunctions using a standardized protocol.Methods:From a group of 230 eyes which underwent DMEK for Fuchs'' endothelial corneal dystrophy (FECD), aphakic and pseudophakic bullous keratopathy, failed full thickness corneal transplants, ICE syndrome, failed DSEK, and TASS the clinical outcomes [best spectacle-corrected visual acuity (BSCVA), central endothelial cell density (ECD)] were evaluated before, and at 6, 12, and 24 months and the success rate, failure rate and postoperative complications were also analyzed.Results:Out of 230 eyes, 144 eyes (70%) had BSCVA 6/9 or better 2 years postoperatively. Mean donor ECD was 2692.23 (range, 2300–3436) cells/mm² preoperatively, which was reduced to 1433.64 (range, 619.0–2272.0) cells/mm² 2 years after DMEK surgery, indicating a mean reduction of 1258 cells/mm² (46%) in ECD.Conclusion:DMEK is a highly successful surgical procedure when following a standard protocol for treating diseases of the corneal endothelium providing a near perfect anatomic restoration and a high degree of visual rehabilitation.     

Therapie von Hornhautendothelerkrankungen mittels DMEK und UT-DSAEK

Various techniques for posterior lamellar keratoplasty have been established for the clinical routine and continuously improved during the last 15 years so that an extremely rapid recovery of vision is possible due to very thin transplants. Descemet membrane endothelial keratoplasty (DMEK) is the method of choice for simple corneal endothelial diseases and has already been applied in complex conditions of the anterior segment. The learning curve for DMEK is comparatively long and the risk of complications in complex anterior segment pathologies is higher than in Descemet’s stripping automated endothelial keratoplasty (DSAEK); however, DMEK results in better visual outcome and less graft rejections than DSAEK. The latest evolution in posterior lamellar transplant surgery is ultrathin DSAEK (UT-DSAEK), where the grafted lamella is much thinner than in conventional DSAEK. Currently available data suggest that the resulting visual acuity after UT-DSAEK is close to the visual acuity seen after DMEK; however, studies comparing the results after DMEK and UT-DSAEK are so far lacking. Whether the transplantation of these very thin DSAEK grafts also results in endothelial cell densities and graft rejection rates comparable to DMEK has to be proven.     

Standardized "no-touch" technique for descemet membrane endothelial keratoplasty

We describe a standardized technique for "no-touch" isolated Descemet membrane transplant, ie, Descemet membrane endothelial keratoplasty (DMEK). All essential steps, including patient preparation and descemetorhexis as well as DMEK graft implantation, orientation, unrolling, centering, appositioning, and fixation, are described in detail. In the management of Fuchs endothelial dystrophy, the technique may provide a best-corrected visual acuity of 20/25 or better (≥ 0.8) in three-quarters of cases and an endothelial cell density of about 1800 to 2000 cells/mm(2) at 6 months after surgery. No-touch DMEK may therefore be a safe and effective procedure for the treatment of corneal endothelial disorders, making endothelial keratoplasty accessible to most corneal surgeons without requiring major investments while providing an unprecedented visual rehabilitation rate and outcome.     

Descemet stripping and endothelial keratoplasty in endothelial dysfunctions: three-month results in 75 eyes

Purpose: To analyze the results of Descemet stripping and endothelial keratoplasty (DSEK) in the first consecutive 75 cases. Materials and Methods: Prospective, non-randomized, non-comparative interventional case series. Seventy-five eyes of 75 patients with endothelial dysfunctions of different etiology, scheduled for DSEK, were included in this study. Healthy donor cornea with a cell count of> 2000 cells/sq mm was considered for transplantation in each case. Indications, operative problems and postoperative complications were noted. Best corrected visual acuity (BCVA), refractive and keratometric astigmatism, central corneal thickness (CCT) and endothelial cell density (ECD) were analyzed for each patient after a minimum follow-up of three months. Results: Main indication was pseudophakic corneal edema and bullous keratopathy in 53 (70.7%) eyes. Seventeen (22.7%) cases had moderate to severe Fuchs' dystrophy with various grades of cataract; and DSEK was combined with manual small-incision cataract surgery (MSICS) with posterior chamber intraocular lens (PCIOL) in those cases. After three months, BCVA was 20/60 or better in 62 (82.7%) cases. Mean refractive and keratometric astigmatism were 1.10 +/- 0.55 diopter cylinder (DCyl) and 1.24 +/- 0.92 DCyl. The CCT and ECD were 670.8 +/- 0.32 microm and 1485.6 +/- 168.6/sq mm respectively. The mean endothelial cell loss after three months was 26.8 +/- 4.24% (range: 13.3-38.4%). Dislocation of donor lenticule occurred in six (8.0%) eyes. Graft failure occurred in one case. Conclusions: Descemet stripping and endothelial keratoplasty is a safe and effective procedure in patients with endothelial dysfunctions with encouraging surgical and visual outcomes. It can be safely combined with MSICS with PCIOL in patients with moderate to severe Fuchs' dystrophy with cataract.     

Descemet's stripping endothelial keratoplasty

PURPOSE OF REVIEW: Descemet's stripping endothelial keratoplasty (DSEK) is rapidly becoming the preferred treatment for corneal endothelial dysfunction. Familiarity with recent advances in techniques and instrumentation can help reduce the initially steep learning curve and incidence of complications. RECENT FINDINGS: DSEK produces excellent visual outcomes with minimal change in corneal surface topography or refraction. It can successfully treat corneal dysfunction associated with Fuchs' endothelial dystrophy, bullous keratopathy, iridocorneal endothelial syndrome or a failed penetrating graft. Donor dissection has become automated, and new techniques have been devised to facilitate graft insertion and unfolding. Some surgeons now routinely perform DSEK with topical anesthesia. Graft detachment is the most frequent early postoperative complication, but new methods can help promote donor adherence. The incidence of graft-rejection episodes is lower after DSEK compared with standard penetrating keratoplasty, possibly because wound healing is a lesser concern, and many DSEK patients are maintained on low-dose topical steroids indefinitely. Early efforts to transplant just the endothelial cell layer show promise. SUMMARY: DSEK provides quicker visual rehabilitation and an improved safety profile compared with standard penetrating keratoplasty. Continued evolution of this relatively new technique is helping to reduce complications and further improve outcomes.     

Histologic evidence of retained fetal layer of the descemet membrane after presumed total removal for endothelial keratoplasty: a possible cause for graft failure

PURPOSE: This is, to our knowledge, the first report of histology after failed Descemet-stripping endothelial keratoplasty (DSEK) surgery in a patient. We describe the interface histology found in a case of donor nonadherence and subsequent graft failure in a patient after DSEK. METHODS: An 83-year-old woman with a history of Fuchs dystrophy underwent DSEK surgery and subsequently underwent full-thickness penetrating keratoplasty (PKP) because of nonadherence of the donor disc and presumed graft failure. Specimens from the initial stripping of the Descemet membrane, the failed donor disc, and the full thickness of the patient's remaining cornea containing the recipient bed after her DSEK and PKP procedures were histologically evaluated by light microscopy. RESULTS: Microscopic examination of the initial stripped recipient Descemet membrane revealed a "delamination" of the Descemet membrane involving the fetal layer. After PKP, histopathologic study of the recipient button revealed residual fetal Descemet membrane retained on the recipient DSEK interface. Examination of the failed donor disc showed healthy tissue. CONCLUSIONS: In DSEK surgery, there are multiple reasons that the donor graft button may fail to adhere to the recipient posterior corneal surface. In this instance, histologic study revealed that the Descemet membrane was split by the stripping, and the fetal layer of the Descemet membrane was retained on the central part of the patient's posterior cornea. Despite histologically normal donor endothelial cells, the inability of the donor tissue to adhere may have been caused by the coating of the central recipient bed with retained fetal Descemet membrane.     

Causes of primary donor failure in descemet membrane endothelial keratoplasty

PURPOSE: To determine the causes of primary failure of donor Descemet membrane transplants in Descemet membrane endothelial keratoplasty (DMEK). DESIGN: Laboratory and clinical study. METHODS: From a larger series of eyes that underwent DMEK for Fuchs endothelial dystrophy or bullous keratopathy, 11 transplanted corneas did not clear within the first week after surgery. During a secondary 'Descemet stripping endothelial keratoplasty' procedure, the first graft was carefully removed and analyzed with light microscopy. For each patient, the surgical video of the initial DMEK procedure was analyzed to determine the cause of transplant failure. RESULTS: With light microscopy, all but two explanted transplants had a endothelial cell density of 1700 cells/mm2 or higher. Three Descemet grafts may have been positioned upside down and three may have failed due to manipulation. One transplant could not be properly attached onto the recipient posterior stroma because of insufficient air-support in a post-vitrectomy eye. For four eyes, no obvious cause of failure could be determined. CONCLUSION: Unexpectedly, graft failure after DMEK may not primarily result from tissue damage during implantation and associated endothelial cell loss. Detached grafts may therefore be managed by early reposition. When the graft is attached after surgery but fails to clear, secondary surgical intervention may be postponed, because these corneas may clear spontaneously after several weeks.     

Descemet stripping with endothelial keratoplasty for treatment of iridocorneal endothelial syndrome

PURPOSE: To describe use of Descemet stripping with endothelial keratoplasty (DSEK) to treat corneal edema associated with iridocorneal endothelial (ICE) syndrome. METHODS: In this retrospective, consecutive, interventional case series, the corneal endothelium was selectively replaced by the DSEK technique in eyes with ICE syndrome. Three eyes were treated at 1 center between June 2005 and July 2006. Descemet membrane and endothelium were stripped from the recipient and an 8- or 8.5-mm-diameter donor button consisting of posterior stroma and healthy endothelium was folded and implanted through a 5-mm incision. An air bubble was used to press the donor tissue against the recipient cornea, allowing it to attach without sutures. In 1 case with extensive peripheral anterior synechiae (PAS), after the PAS were broken, the anterior chamber was shallow, so a temporary anchor suture was placed in the peripheral edge of the donor tissue to help ensure that it would unfold in the correct orientation. RESULTS: DSEK successfully resolved corneal edema in 3 male patients with unilateral ICE syndrome who were 47 to 67 years of age. Follow-up ranged from 1 to 14 months. Best spectacle-corrected visual acuity at the most recent visit was 20/20 to 20/30, with a mean refractive cylinder of 1.2 D. CONCLUSIONS: Selective replacement of dysfunctional endothelium with DSEK can successfully treat corneal edema and associated visual loss and pain caused by ICE syndrome. Visual recovery is rapid and refractive changes are minimal compared with replacement of the full corneal thickness with a traditional penetrating keratoplasty.     

Endothelial keratoplasty: a revolution in evolution

Endothelial keratoplasty (EK) is continually evolving both in surgical technique and clinical outcomes. Descemet's stripping endothelial keratoplasty (DSEK) has replaced penetrating keratoplasty (PK) as the treatment of choice for corneal endothelial dysfunction. It is safe and predictable and offers early visual rehabilitation. Newer iterations include Descemet's membrane endothelial keratoplasty, Descemet's membrane automated endothelial keratoplasty, and other hybrid techniques. Early data on these newer EK techniques suggests that they provide significantly better visual outcomes compared to DSEK. Initial 5-year survival data indicates that EK is at least comparable to PK, and more widespread survival data is anticipated. Further work is needed to simultaneously optimize visual outcomes, refractive predictability, and endothelial cell survival, as well as surgical techniques of donor preparation and insertion.     

Outcomes of the first 250 eyes of Descemet membrane endothelial keratoplasty: Canadian centre experience

Objective

To report and analyze the clinical outcomes of the first 250 cases of Descemet membrane endothelial keratoplasty (DMEK).

Outcomes of Descemet’s stripping endothelial keratoplasty in eyes with failed therapeutic penetrating keratoplasty

Purpose: To report the results of Descemet’s stripping endothelial keratoplasty (DSEK) for failed therapeutic penetrating keratoplasty (PK). Methods: Twenty‐seven eyes of 27 patients undergoing DSEK for failed therapeutic PK were analysed. Results: The mean age of the patients was 36 ± 13.9 years (range: 14–70 years). The median size of the therapeutic graft was 10 mm (inter‐quartile range; IQR 9.5–11 mm). Descemet’s membrane stripping was performed in all eyes. Graft clarity was achieved in 20/27 eyes. Six eyes had primary graft failure, and one had interface keratitis in the early postoperative period. In all eyes with primary graft failure, there was progressive stromal vascularization, which led to haziness in the graft. Late postoperative complications were rejection in four eyes, infection in two eyes, secondary graft failure in one eye and vortex keratopathy in one eye. Graft size was found to be a significant risk factor for graft rejection in this series. At the last follow‐up visit, the best‐corrected visual acuity was ≥20/40 in 5/27 eyes (18.5%), 20/60–20/40 in 12/27 eyes (44.4%), 20/100–20/60 in 3/27 eyes (1.5%) and ≤20/200 in 7/27 eyes (25.9%). Conclusions: Considering the limited success of repeat PK in failed large therapeutic keratoplasty, DSEK is a viable option for visual rehabilitation in these eyes, however; visual acuity may be limited due to sub‐epithelial/stromal or interface scarring.     

Queratoplastia penetrante temprana después de queratitis fúngica de la interface en la queratoplastia endotelial de la membrana de Descemet

In this case-report we describe the first reported case of early-onset fungal interface keratitis (IK) after Descemet Membrane Endothelial Keratoplasty (DMEK) successfully treated with penetrating keratoplasty (PK) during the active stage of infection. A patient with graft failure after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) was operated on with DMEK. Donor rim culture and broth were positive for Candida albicans. Several interface infiltrates were confirmed and localized using anterior segment optical coherence tomography. Three days after diagnosis, observing clear signs of intraocular infection, the graft was removed with simultaneous washed-up of anterior chamber with fluconazole 1% followed by a PK and intrastromal corneal injections of fluconazole. A best-corrected visual acuity of 20/20 was achieved. This case highlights the importance of analysing every donor rim and broth, despite the patient doesn’t show any symptoms or signs during the post-operative period. PK is a viable treatment option in early-onset interface keratitis.     

Donor descemet membrane detachment after endothelial keratoplasty

PURPOSE: To describe histopathologic characteristics of an endothelial keratoplasty (EK) that was performed to treat a previously failed penetrating keratoplasty (PK) and in which the cornea failed to clear after partial detachment of Descemet membrane from the EK donor button. The Descemet membrane and endothelium from the PK were intentionally retained during the EK procedure. METHODS: After EK, the cornea failed to fully clear in 5 months, and a PK was performed. The removed corneal button was grossly described and routinely processed for hematoxylin-eosin (H&E) and periodic acid-Schiff (PAS) staining, with photographs taken of any pertinent findings. RESULTS: Grossly on the endothelial side, there was some adherent iris pigment delineating an off-center fold in the EK Descemet membrane, consistent with intraoperative observation of a fold across the width of the donor button and postoperative slit-lamp images showing partial detachment of Descemet membrane. Microscopic examination revealed a recipient corneal button from a prior PK centrally and EK donor button attached posteriorly. Descemet membrane was not stripped from the prior PK during EK and was intact. No endothelial cells were detected on the PK Descemet membrane. The anterior stromal surface of the EK was well apposed to the prior PK Descemet membrane, with no pseudoanterior chamber or cleft of any type noted between them. The EK Descemet membrane had a central fold, and the endothelium was markedly attenuated. CONCLUSION: The EK graft was well apposed with apparent good adherence to the recipient's prior failed PK, and early endothelial failure was attributable to partial Descemet membrane detachment.     

Descemet-stripping endothelial keratoplasty: improvement in vision following replacement of a healthy endothelial graft

We describe a case of endothelial graft exchange in a patient who had inadequate vision without a clinically identifiable cause following Descemet-stripping endothelial keratoplasty (DSEK). The initial DSEK was performed with a hand-dissected donor, and the replacement graft was prepared with an automated microkeratome. The best spectacle-corrected visual acuity (BSCVA) improved from 20/50 before replacement to 20/25 after replacement. Although DSEK provides rapid recovery of excellent vision, few patients achieve a BSCVA of 20/20. Some have substandard vision with no clinically identifiable cause. This case demonstrates that replacing a hand-prepared graft with an automated microkeratome-prepared graft may improve vision in patients with no identifiable cause for visual loss.     

Preliminary clinical results of Descemet membrane endothelial keratoplasty

PURPOSE: To describe the preliminary clinical results of selective transplantation of organ cultured, donor Descemet membrane (DM) carrying autologous corneal endothelium through a 3.5-mm incision, tentatively named Descemet membrane endothelial keratoplasty (DMEK), for the management of corneal endothelial disorders. DESIGN: Nonrandomized clinical study. METHODS: In 10 patients with Fuchs endothelial dystrophy or pseudophakic bullous keratopathy, DMEK was performed. A 3.5-mm clear corneal tunnel incision was made, the anterior chamber was filled with air, and DM was stripped off from the posterior stroma. A 9.0-mm diameter DM roll was harvested from an organ cultured donor corneo-scleral rim, and inserted into a recipient anterior chamber. The donor tissue was gently unfolded, positioned onto the posterior stroma, and secured by completely filling the anterior chamber with air for 30 minutes. RESULTS: At one month, six eyes had a best-corrected visual acuity of 0.5 (20/40) or better, and three eyes reached 1.0 (20/20). At six months, the endothelial cell density averaged 2030 (+/-373) cells/mm(2) (n = 7). Three eyes showed a complete detachment of the donor tissue in the early postoperative course that was managed by removal of the transplant and a secondary Descemet stripping endothelial keratoplasty procedure. CONCLUSION: DMEK may have potential to become the most preferable technique to manage corneal endothelial disorders, because it provides quick and nearly complete visual rehabilitation. Because the donor tissue required can be prepared from organ cultured corneo-scleral rims, the procedure may be readily accessible to most corneal surgeons.     

Descemet membrane endothelial keratoplasty (DMEK)

PURPOSE: To describe Descemet membrane endothelial keratoplasty (DMEK) with organ cultured Descemet membrane (DM) in a human cadaver eye model and a patient with Fuchs endothelial dystrophy. METHODS: In 10 human cadaver eyes and 1 patient eye, a 3.5-mm clear corneal tunnel incision was made. The anterior chamber was filled with air, and the DM was stripped off from the posterior stroma. From organ-cultured donor corneo-scleral rims, 9.0-mm-diameter "DM rolls" were harvested. Each donor DM roll was inserted into a recipient anterior chamber, positioned onto the posterior stroma, and kept in position by completely filling the anterior chamber with air for 30 minutes. RESULTS: In all recipient eyes, the donor DM maintained its position after a 30-minute air-fill of the anterior chamber followed by an air-liquid exchange. In the patient's eye, 1 week after transplantation, best-corrected visual acuity was 1.0 (20/20) with the patient's preoperative refraction, and the endothelial cell density averaged 2350 cells/mm. CONCLUSION: DMEK may provide quick visual rehabilitation in the treatment of corneal endothelial disorders by transplantation of an organ-cultured DM transplanted through a clear corneal tunnel incision. DMEK may be a highly accessible procedure to corneal surgeons, because donor DM sheets can be prepared from preserved corneo-scleral rims.