Four-Year Survival of Descemet Membrane Endothelial Keratoplasty in Patients With Previous Glaucoma Surgery

Contact Lens-Assisted DMEK for Corneal Decompensation With an Anterior Chamber Intraocular Lens: A Novel Technique

PURPOSE

To describe a novel technique in which a contact lens was used to facilitate Descemet membrane endothelial keratoplasty (DMEK) in an eye with an anterior chamber intraocular lens (ACIOL).

METHODS

A 71-year-old man with a long-standing ACIOL developed bullous keratopathy. As the patient was at high risk of complications due to multiple ocular comorbidities, DMEK was performed with the ACIOL left in the anterior chamber. An inserted cosmetic contact lens was used as a platform for the graft unfolding.

RESULTS

Partial graft detachment on the third postoperative day required rebubbling. This successfully cleared up the cornea after a few weeks. At the one-month follow-up, the uncorrected distance visual acuity improved to 20/50, with an endothelial cell loss of 35.2%. Steroid-induced ocular hypertension necessitated a trabeculectomy by the fifth postoperative month. At the sixth follow-up month, endothelial cell loss was 64%.

CONCLUSIONS

Contact lens-assisted DMEK is a safe procedure for eyes with an ACIOL. However, good foresight is needed regarding whether the ACIOL should be kept or exchanged.

Endothelial Keratoplasty Following Glaucoma Filtration Surgery: A UK Tertiary Eye Care Referral Centre Experience

Purpose: To compare the postoperative complications and clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK) in eyes with previous glaucoma filtering surgery. Methods: In this retrospective comparative case series, we analysed postoperative visual acuity and intraocular pressure, graft survival, rate of graft detachment and/or dislocation, number of rebubbling and/or graft repositioning procedures, and graft rejection or failure (primary and secondary). Results: Sixteen eyes with DMEK and 80 eyes with DSAEK with previous glaucoma surgery were studied. The results were recorded at 3 and 12 months postoperatively. No statistically significant differences in postoperative visual acuity were found between the two groups at any stage of the follow-up. Intraocular pressure was lower in the DMEK group at the follow-up stage of 3 (p = 0.0022) and 12 months (p = 0.0480). Visually significant graft detachment was recorded in 31.3% and 22.5% of DMEK and DSAEK cases, respectively (p = 0.4541). All DMEK detachments (n = 5) were managed with slit-lamp rebubbling. Out of 18 graft detachments in the DSAEK group, 2 grafts were observed due to small graft detachment, 6 large graft detachments underwent rebubbling performed in the operating theatre, and 10 eyes needed primary graft repositioning for graft dislocation. Conclusions: DMEK is a feasible option to treat endothelial failure in complex eyes with previous glaucoma surgery. In the DMEK group, visual acuity outcomes and possibly postoperative intraocular pressure control were better compared with the DSAEK group.

Donor Corneal Endothelial Cell Maturity and Its Impact on Graft Survival in Glaucoma Patients Undergoing Corneal Transplantation

PURPOSE

To examine corneal graft survival via corneal endothelial cell density (ECD) and corneal endothelial cell loss (ECL) at 5 years post-transplantation in the eyes of patients with and without a history of undergoing glaucoma surgery according to the maturity of the donor corneal endothelial cells.

DESIGN

Prospective cohort study.

METHODS

This prospective cohort study included 17 patients with glaucoma and 51 patients without glaucoma who underwent Descemet's stripping automated endothelial keratoplasty or penetrating keratoplasty at the Baptist Eye Institute, Kyoto, Japan, between October 2014 and October 2016. Human corneal endothelial cells were cultured from residual peripheral donor cornea tissue, and the maturity of the cells was evaluated by cell surface markers (ie, CD166+, CD44-/dull, CD24-, and CD105-) using fluorescence-activated cell sorting. Kaplan-Meier analysis or the chi-square test was used to assess the rate of successful corneal graft survival post-transplantation.

RESULTS

At 36 months postoperatively, the mean ECD and ECL in the glaucoma-bleb eyes were 1197 ± 352 cells/mm2 and 55.5% ± 13.9% in the high-maturity group and 853 ± 430 cells/mm2 and 67.7% ± 18.1% in the low-maturity group, respectively. Kaplan-Meier analysis revealed that at 5 years postoperatively, the overall rate of survival was 45%, that is, 100% in the high-maturity group and 25% in the low-maturity group (P < .05).

CONCLUSIONS

The findings in this prospective cohort study revealed that the use of donor corneal grafts containing mature-differentiated corneal endothelial cells could maintain the survival of the transplanted graft for a long-term period, even in patients with a history of undergoing glaucoma surgery.

Suture Fixation to Reduce Graft Detachment in Descemet Stripping Endothelial Keratoplasty

PURPOSE

The aim of this study was to report the outcomes of graft fixation using interrupted, full-thickness sutures on graft detachment after Descemet stripping endothelial keratoplasty (DSEK).

METHODS

All DSEK procedures performed at Mayo Clinic, Rochester, MN, from 2015 through 2022 were retrospectively reviewed. Risk factors for graft detachment were defined as previous incisional glaucoma surgery, previous penetrating keratoplasty, or absence of the normal lens-capsule barrier. Cases were categorized into sutured, high-risk grafts; unsutured, high-risk grafts; and unsutured, low-risk grafts. The primary outcome was graft detachment, and secondary outcomes were early graft failure and graft clarity at 12 months after surgery.

RESULTS

Demographics between the high-risk groups were similar for sex and age at the time of surgery. Graft detachment occurred in 4 of 97 sutured, high-risk eyes (4.1%) and 24 of 119 unsutured high-risk eyes (20.2%) ( P = 0.002). In comparison, graft detachment occurred in 18 of 181 unsutured low-risk eyes (9.9%). The incidence of early graft failure was 2.1%, 5.0%, and 3.3% and late graft failure by 12 months was 9.8%, 12.8%, and 4.2%, respectively.

CONCLUSIONS

In eyes with high-risk factors for graft detachment, suture fixation of the graft in DSEK decreased graft detachment to a rate at least as low as that in low-risk eyes.

Descemet Stripping Automated Endothelial Keratoplasty versus Descemet Membrane Endothelial Keratoplasty for Fuchs Endothelial Corneal Dystrophy: A National Registry-Based Comparison

PURPOSE

To compare the outcome between posterior lamellar corneal transplant procedures for Fuchs endothelial corneal dystrophy, taking preoperative patient characteristics in consideration. Surgical methods compared were Descemet membrane endothelial keratoplasty (DMEK), Descemet stripping automated endothelial keratoplasty (DSAEK), and DSAEK with concomitant cataract surgery (phacoemulsification plus DSAEK).

DESIGN

Registry-based study with propensity score matching.

PARTICIPANTS

One thousand six hundred seventy-seven patients from all Swedish corneal transplantation units treated from 2012 through 2019.

METHODS

All patients undergoing endothelial keratoplasty performed from 2012 through 2019 with completed 2-year follow-up data reported to The Swedish Corneal Transplant Register were included, totaling 1677 patients. Three comparable groups (DMEK, DSAEK, and phacoemulsification plus DSAEK) with 216 patients in each group were generated with propensity score matching based on preoperative visual acuity, age, sex, year of surgery, and preoperative risk factors such as inflammation, vascularization, and glaucoma.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (BCVA) at the 2-year follow-up, frequency of graft dislocation, graft rejection episodes, and graft failure within 2 years including primary graft failure.

RESULTS

The preoperative corneal status was affected more severely in the DSAEK group before matching. In the matched groups, the median BCVA 2 years after surgery was 0.1 logarithm of the minimum angle of resolution (logMAR) in both the DMEK and the phacoemulsification plus DSAEK groups and 0.15 logMAR in the DSAEK group (P = 0.001). The frequency of graft dislocation was higher among the patients undergoing phacoemulsification plus DSAEK, but the frequency of graft failure and primary graft failure was higher in the DMEK group.

CONCLUSIONS

Visual acuity improved in most patients (90%) with all 3 surgical methods. However, DMEK and phacoemulsification plus DSAEK reached higher levels of visual acuity 2 years after surgery, and phacoemulsification plus DSAEK was superior considering graft survival rate. All 3 surgical procedures showed both strengths and weaknesses, suggesting that the choice of surgical method should be individualized, taking into consideration not only the cornea, but each patient's complete medical status as well as the entire course of postoperative medical care.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Graft Survival, Graft Rejection, and Glaucoma in a Consecutive Series of Descemet Stripping Endothelial Keratoplasty

PURPOSE

The goal of this study was to compare outcomes of Descemet stripping endothelial keratoplasty (DSEK) in eyes with glaucoma and abnormal anatomy to eyes with Fuchs endothelial corneal dystrophy (FECD).

METHODS

In a retrospective interventional series of all cases of DSEK between April 1, 2006, and November 30, 2015, recipient diagnosis, preoperative glaucoma status, concurrent surgical procedures, and graft outcomes were recorded. Graft survival, risk of rejection, and subsequent glaucoma surgery were estimated by using Kaplan-Meier analysis with risk factors determined by proportional hazard models.

RESULTS

Of 703 DSEKs in 666 eyes (509 subjects), the main recipient diagnoses were FECD (n = 496), pseudophakic corneal edema (n = 112), and failed graft (n = 83). Glaucoma was present in 150 cases before DSEK. Overall graft survival was 85%, 75%, and 71% at 5, 10, and 12 years, respectively, and for FECD without glaucoma was 95%, 89%, and 87% at 5, 10, and 12 years, respectively. Independent risk factors for graft failure included recipient diagnoses of pseudophakic corneal edema (HR = 8.3, P < 0.001), failed graft (HR = 6.4, P < 0.001), and preoperative medical glaucoma (HR = 7.1, P < 0.001) or surgical glaucoma (HR = 12.3, P < 0.001). Preoperative glaucoma treated by previous surgery resulted in graft survival of 28% at 10 years. Preoperative glaucoma was associated with an increased risk of graft rejection (HR = 6.8, P < 0.001) and subsequent glaucoma surgery (HR > 17.4, P < 0.001).

CONCLUSIONS

Preoperative glaucoma increases the risk of graft failure, graft rejection, and needing subsequent glaucoma surgery in the first decade after DSEK. With previous glaucoma surgery, DSEK graft survival was more favorable compared with published reports of Descemet membrane endothelial keratoplasty.

Fuchs Dystrophy and Cataract: Diagnosis, Evaluation and Treatment

Corneal endothelium plays an important role in maintaining hydration homeostasis and clarity of the cornea. Fuchs endothelial corneal dystrophy (FECD) affects the corneal endothelium resulting in edema and characteristic excrescences on the Descemet's membrane known as corneal guttae. Descemet membrane endothelial keratoplasty (DMEK) has evolved to become the standard of care for patients with FECD with excellent visual acuity outcomes. Patients with FECD may have coexisting cataracts and therefore may require a cataract surgery, which increases the risk of corneal decompensation. The presence of FECD may not only influence the choice of intraocular lens but vision outcomes can also be affected by the corneal condition. The ability to combine the surgeries further raises important considerations regarding the timing and sequence of DMEK and cataract extraction for patients with FECD. This review provides a guide for corneal surgeons in choosing between endothelial keratoplasty and cataract surgery-alone, in combination or sequential-in their management of patients with FECD.

DMEK graft: One size does not fit all

Descemet membrane endothelial keratoplasty (DMEK) is a popular procedure for the treatment of corneal endothelial diseases mainly targeting Fuchs endothelial corneal dystrophy (FECD) and pseudophakic bullous keratopathy (PBK). Although DMEK has multiple advantages, it is challenging in terms of graft preparation and delivery. One of the crucial factors of DMEK graft preparation is determining the size of the graft. Evaluating risks and benefits of transplanting larger or smaller grafts compared with the descemetorhexis performed following a standard DMEK procedure thus becomes important. Advanced techniques like pre-loaded DMEK requires pre-selection of graft diameter without physical examination of the eye making it more challenging. Therefore, recognizing the benefits of graft size and the number of transplanted endothelial cells becomes essential. Smaller DMEK grafts have been preferred and accepted for grafting. Larger diameter grafts have advantages but can be challenging due to higher detachment rates. We thus aim to review the challenges of preparing and delivering DMEK tissues with small or large diameter based on selected descemetorhexis area, discuss the outcomes based on different graft sizes, highlight related complications and suggest which cases may benefit from adopting smaller or larger graft size.

Risk Factors for Descemet Membrane Endothelial Keratoplasty Rejection: Current Perspectives- Systematic Review

Descemet membrane endothelial keratoplasty (DMEK) is a corneal endothelial transplantation procedure with selective removal of a patient's defective Descemet membrane and endothelium. It is replaced with a healthy donor Descemet membrane and endothelium without a stromal component. Corneal graft rejection can be at the level of epithelium, stroma as well endothelium. DMEK graft rejection is relatively less common than rejection with DSAEK or penetrating keratoplasty, and a good outcome may be achieved with prompt management. The clinical picture of DMEK rejection is usually similar to endothelial rejection in Descemet Stripping Endothelial Keratoplasty (DSEK/DSAEK), which generally manifests as pain, redness, reduction in visual acuity, stromal edema, endothelial rejection line, keratic precipitates at the back of the cornea and corneal neovascularization. However, more subtle forms of rejection or immune reactions are more common in DMEK compared to DSAEK eyes. Early clinical diagnosis, prompt intervention, and meticulous management safeguard visual acuity and graft survival in these cases. Intensive topical steroids form the mainstay in the management of DMEK rejection. Sometimes, oral or intravenous steroids or other systemic immunomodulators may be required. DMEK graft failure can be primary or secondary, and failure usually requires a second procedure in the form of repeat DMEK or DSEK or penetrating keratoplasty (PKP). A detailed literature search was performed using search engines such as Google Scholar, PubMed, and Google books, and a comprehensive review on DMEK rejection was found to be lacking. This review is a comprehensive update on the risk factors, pathophysiology, primary and secondary graft failure, recent advances in diagnosis, prevention of rejection, and updates in the management of DMEK rejection. The review also discusses the differential diagnosis of DMEK failure and rejection, prognosis, and future perspectives considering DMEK failure and rejection.

Graft failure rate and complications after Descemet membrane endothelial keratoplasty in eyes with pre-existing glaucoma

PURPOSE

To evaluate the outcome of Descemet Membrane Endothelial Keratoplasty (DMEK) in eyes with pre-existing glaucoma.

DESIGN

In this retrospective, observational case series we included data of 150 consecutive DMEKs in eyes with pre-existing glaucoma of 150 patients after excluding data of the second treated eye of each patient and of re-DMEKs during follow-up. Cumulative incidences of IOP elevation (IOP > 21 mmHg or ≥ 10 mmHg increase in IOP from preoperative value), post-DMEK glaucoma (need of an additional intervention due to worsening of the IOP), graft rejection, and graft failure rate were analyzed using Kaplan-Meier survival analysis. COX regression analysis was used to evaluate independent risk factors.

RESULTS

The 36-month cumulative incidence of IOP elevation was 53.5% [95 CI 43.5-63.5%] and of post-DMEK glaucoma 36.3% [95 CI 26.3-46.3%]. Graft rejection occurred with a 36-month cumulative incidence of 9.2% [CI 95% 2.3-16.1]. None of the analyzed risk factors increased the risk for the development of graft rejection. The 36-month cumulative incidence of graft failure was 16.6% [CI 95% 8.4-24.8]. Independent risk factors for graft failure were the indication for DMEK "status after graft failure" (n = 16) compared to Fuchs' dystrophy (n = 74) (p = 0.045, HR 8.511 [CI 95% 1.054-68.756]) and pre-existing filtrating surgery via glaucoma drainage device (GDD) (n = 10) compared to no surgery/iridectomy (n = 109) (p = 0.014, HR 6.273 [CI 95% 1.456-27.031]).

CONCLUSION

The risks of postoperative complications (IOP elevation, post-DMEK glaucoma, graft rejection, and graft failure) in patients with pre-existing glaucoma are high. In particular, pre-existing filtrating surgery via GDD implantation-but not trabeculectomy-and DMEK after graft failure increase the risk of graft failure.

The Biologic Character of Donor Corneal Endothelial Cells Influences Endothelial Cell Density Post Successful Corneal Transplantation

Purpose

Corneal endothelial cell density (ECD) gradually decreases after corneal transplantation by unknown biologic, biophysical, or immunologic mechanism. Our purpose was to assess the association between donor corneal endothelial cell (CEC) maturity in culture and postoperative endothelial cell loss (ECL) after successful corneal transplantation.

Design

Prospective cohort study.

Participants

This cohort study was conducted at Baptist Eye Institute, Kyoto, Japan, between October 2014 and October 2016. It included 68 patients with a 36-month follow-up period who had undergone successful Descemet stripping automated endothelial keratoplasty (DSAEK) or penetrating keratoplasty.

Methods

Human CECs (HCECs) from remaining peripheral donor corneas were cultured and evaluated for maturity by surface markers (CD166⁺, CD44^-/dull, CD24^-, and CD105^-) using fluorescence-activated cell sorting. Postoperative ECD was assessed according to the mature-differentiated HCEC contents: high-maturity group: > 70%, middle-maturity group: 10% to 70%, low-maturity group: < 10%. The successful rate of ECD maintained at 1500 cells/mm² at 36 months postoperative was analyzed using the log-rank test.

Main Outcome Measures

Endothelial cell density and ECL at 36 months postoperative.

Results

The 68 included patients (mean [standard deviation] age 68.1 [13.6] years, 47.1% women, 52.9% DSAEK). The high, middle, and low-maturity groups included 17, 32, and 19 eyes, respectively. At 36 months postoperative, the mean (standard deviation) ECD significantly decreased to 911 (388) cells/mm² by 66% in the low-maturity group, compared with 1604 (436) by 40% and 1424 (613) cells/mm² by 50% in the high and middle-maturity groups (P < 0.001 and P = 0.007, respectively) and the low-maturity group significantly failed to maintain ECD at 1500 cells/mm² at 36 months postoperative (P < 0.001). Additional ECD analysis for patients who underwent DSAEK alone displayed a significant failure to maintain ECD at 1500 cells/mm² at 36 months postoperative (P < 0.001).

Conclusions

The high content of mature-differentiated HCECs expressed in culture by the donor peripheral cornea was coincident with low ECL, suggesting that a high-maturity CEC content predicts long-term graft survival. Understanding the molecular mechanism for maintaining HCEC maturity could elucidate the mechanism of ECL after corneal transplantation and aid in developing effective interventions.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Impact of vaccination on keratoplasty

PURPOSE OF REVIEW

Corneal graft rejection has been reported after coronavirus disease 2019 (COVID-19) vaccination. The purpose of this review is to evaluate the literature regarding corneal graft rejection after vaccination, including rejection rates and risk factors. We aim to create a framework to identify patients who are at higher risk for graft rejection and may warrant consideration of prophylactic interventions.

RECENT FINDINGS

Graft rejection has been reported following administration of mRNA, viral vector, and inactivated whole-virion COVID-19 vaccines. Most cases had additional risk factors associated with rejection. Vaccination increases circulation of proinflammatory cytokines, CD4+ and CD8+ T-cell responses, and antispike neutralizing antibody, all of which may contribute to graft rejection. Two prospective studies have found no relationship between recent vaccination and rejection but 20% of cornea specialists report to have seen a vaccine-associated rejection and 22% recommend delaying vaccination in certain circumstances. Many specialists recommend prophylactic topical corticosteroids before and after vaccination to mitigate rejection risk but there is no evidence to support this practice on a wider scale.

SUMMARY

Our framework identified 96.8% of penetrating keratoplasty patients with vaccine-associated rejection as higher risk. Further research is needed in order to develop evidence-based guidelines.

Corneal Endothelial Cell Loss in Glaucoma and Glaucoma Surgery and the Utility of Management with Descemet Membrane Endothelial Keratoplasty (DMEK)

The corneal endothelium has a crucial role in maintaining a clear and healthy cornea. Corneal endothelial cell loss occurs naturally with age; however, a diagnosis of glaucoma and surgical intervention for glaucoma can exacerbate a decline in cell number and impairment in morphology. In glaucoma, the mechanisms for this are not well understood and this accelerated cell loss can result in corneal decompensation. Given the high prevalence of glaucoma worldwide, this review aims to explore the abnormalities observed in the corneal endothelium in differing glaucoma phenotypes and glaucoma therapies (medical or surgical including with new generation microinvasive glaucoma surgeries). Descemet membrane endothelial keratoplasty (DMEK) is increasingly being used to manage corneal endothelial failure for glaucoma patients and we aim to review the recent literature evaluating the use of this technique in this clinical scenario.

[Descemet membrane endothelial keratoplasty after implantation of glaucoma drainage devices]

Secondary decompensation of corneal endothelium, including transplanted, is a frequent long-term complication of glaucoma drainage surgery. According to literature data, after implantation of a glaucoma drainage device into the anterior chamber, the speed of endothelial cells density (ECD) loss increases significantly.

PURPOSE

To study the possibility of performing modified Descemet membrane endothelial keratoplasty (DMEK) with maximum graft diameter, and to assess its short-term effectiveness in the treatment of bullous keratopathy (BK) in the presence of a glaucoma drainage device in the anterior chamber.

MATERIAL AND METHODS

Modified surgery ³/₄-DMEK was performed in 9 eyes of 7 patients with BK and Ahmed glaucoma drainage using graft of maximum diameter (11±1 mm). Average follow-up time was 15.3±2.5 months (12 to 18 months).

RESULTS

No intraoperative or postoperative complications were observed. Mean ECD after 12 months amounted to 1664±346 cells/mm², which corresponds to ECD reduction of 34±9.6% (24 to 49%) in comparison to preoperative values. Mean best corrected visual acuity 12 months after surgery increased from 0.04±0.03 (0.01 to 0.1) to 0.3±0.2 (0.04 to 0.7). The last follow-up examination revealed all corneas to have preserved transparency and stable pachymetry measurements (from 488 to 548 µm).

CONCLUSION

Performing ³/₄-DMEK with a mega graft for treatment of BK after drainage surgery is technically possible. Absence of Descemet membrane (DM) donor and preservation of DM recipient in the drainage tube plane eliminates its contact with the endothelium. Maximum graft diameter should in the long term help prolong the effectiveness of the surgery.

Graft survival of Descemet membrane endothelial keratoplasty (DMEK) in corneal endothelial decompensation after glaucoma surgery

Purpose

This study aims to assess the results, rebubbling rate, and graft survival after Descemet membrane endothelial keratoplasty (DMEK) with regard to the number and type of previous glaucoma surgeries.

Methods

This is a clinical retrospective review of 1845 consecutive DMEK surgeries between 07/2011 and 08/2017 at the Department of Ophthalmology, University of Cologne. Sixty-six eyes were included: group 1 (eyes with previous glaucoma drainage devices (GDD); n = 27) and group 2 (eyes with previous trabeculectomy (TE); n = 39). Endothelial cell loss (ECL), central corneal thickness, graft failure, rebubbling rate, and best spectacle-corrected visual acuity (BSCVA) up to 3 years after DMEK were compared between subgroups of patients with different numbers of and the two most common types of glaucoma surgeries either GDD or TE or both.

Results

Re-DMEK rate due to secondary graft failure was 55.6% (15/27) in group 1 and 35.9% in group 2. The mean graft survival time in group 1 was 25 ± 11 months and 31.3 ± 8.6 months in group 2 (p = 0.009).

ECL in surviving grafts in group 1 was 35% (n = 13) at 6 months, 36% at 12 months (n = 8), and 27% (n = 4) at 2 years postoperatively. In group 2, ECL in surviving grafts was 41% (n = 10) at 6 months, 36% (n = 9) at 12 months, and 38% (n = 8) at 2 years postoperatively. Rebubbling rate in group 1 was 18.5% (5/27) and 35.9% (14/39) in group 2 (p = 0.079).

Conclusion

Eyes with previous GDD had no higher risk for an increased rebubbling rate but a higher risk for a re-DMEK due to secondary graft failure with a mean transplant survival time of about 2 years. Compared to eyes with preexisting glaucoma drainage device, eyes after trabeculectomy had less secondary graft failures and a longer mean graft survival rate.

Four-Year Survival Comparison of Endothelial Keratoplasty Techniques in Patients With Previous Glaucoma Surgery

PURPOSE

To compare 4-year survival outcomes of Descemet membrane endothelial keratoplasty (DMEK) and Descemet-stripping automated endothelial keratoplasty (DSAEK) in eyes with previous glaucoma surgery.

METHODS

This is a retrospective, comparative case series, including patients with previous trabeculectomy or glaucoma drainage device implantation, who later underwent either DMEK (n = 48) or DSAEK (n = 41). Follow-up was limited to 12 to 60 months to prevent bias. Primary outcomes were graft survival and rejection. Secondary outcomes were best spectacle-corrected visual acuity (BSCVA), detachment/rebubble, endothelial cell loss, and intraocular pressure elevations.

RESULTS

Baseline characteristics, follow-up duration, and preexisting glaucoma parameters did not differ significantly between the groups. Graft survival probability after DMEK and DSAEK was 75% and 75% at 1 year, 63% and 50% at 2 years, 49% and 44% at 3 years, 28% and 33% at 4 years, and 28% and 29% at 5 years, respectively (P = 0.899 between the groups). Graft rejection rates were 20.8% and 19.5%, respectively (P = 1.000). Primary failure, rebubbling, endothelial cell loss, and intraocular pressure elevation did not differ significantly between the groups. Preoperative BSCVA did not differ between the groups (P = 0.821). Postoperative BSCVA was significantly better in the DMEK group at 6, 12, and 24 months (P < 0.001, P = 0.022, and P = 0.047, respectively). In a multivariable model (R2 = 0.576), the type of surgery was the only significant factor affecting postoperative BSCVA, in favor of DMEK (coefficient value -0.518, P = 0.002).

CONCLUSIONS

In eyes with previous glaucoma surgery, DMEK and DSAEK had comparably low survival and comparably high rejection rates. Postoperative visual acuity might be better after DMEK in this setting.

Descemet Membrane Endothelial Keratoplasty in Eyes With Chronic Ocular Hypotony Following Glaucoma Surgery

PURPOSE

To assess the outcomes of Descemet membrane endothelial keratoplasty (DMEK) in patients with ocular hypotony after glaucoma surgery.

DESIGN

retrospective case series.

METHODS

Setting: Multicenter retrospective case series.

PATIENTS/INTERVENTION

Hypotonic eyes with prior glaucoma surgery that underwent DMEK between January 2013 and July 2019 in Israel (2 centers) and Canada (1 center).

MAIN OUTCOME MEASURES

Pre/postoperative corrected distance visual acuity, complications, 3- to 6-month endothelial cell loss, and intraocular pressure (IOP).

RESULTS

The study included 11 DMEK procedures performed in 10 eyes of 4 males and 6 females aged 65-84 years. Indications for DMEK included 7 cases of pseudophakic bullous keratopathy, 2 cases of failed DMEK, and 1 case of failed Descemet stripping automated endothelial keratoplasty. All patients had at least 1 previous trabeculectomy operation. One patient had 2 trabeculectomy procedures and 1 tube placement procedure. Two patients had 1 previous trabeculectomy and 1 tube placement procedure. The corrected distance visual acuity improved significantly from 1.52 ± 0.68 logarithm of minimal angle of resolution preoperatively to 0.49 ± 0.32 logarithm of minimal angle of resolution 3 months postoperatively (P < .001). Rebubbling occurred in 3 of 11 procedures (27%). Endothelial cell loss 6-12 months postoperatively was 60% ± 16% (range, 41%-89%). At the last follow-up visit, 6 of 11 (54%) of the grafts were clear. The remaining 5 grafts failed at 1-4 years postoperatively. The preoperative IOP was 5.1 ± 1.6 mm Hg (range, 1-7 mm Hg). In all but one patient, the postoperative IOP did not increase to more than 13 mm Hg. In 2 cases, the IOP decreased from 5 and 7 mm Hg preoperatively to 1 mm Hg 1 year postoperatively.

CONCLUSION

DMEK is a valid procedure for the treatment of corneal edema in hypotonic eyes after glaucoma procedures. These eyes benefit from improvement in vision after DMEK.

Three-quarter DMEK in eyes with glaucoma draining devices to avoid secondary graft failure

PURPOSE

To present a case series of a modified three-quarter Descemet's membrane endothelial keratoplasty (3/4-DMEK) technique to treat pseudophakic bullous keratopathy in the presence of a glaucoma drainage device (GDD) tube in the anterior chamber by reducing the risk of donor endothelial damage due to absence of donor endothelial cells overlying the GGD tube area.

METHODS

In this prospective case series, four eyes of three patients with stable glaucoma underwent 3/4-DMEK surgery for pseudophakic bullous keratopathy after GDD insertion. The patients were followed up to 24 ± 2.5 months postoperatively.

RESULTS

No intraoperative or postoperative complications were noted. The average central endothelial cell density (ECD) was 1093 ± 74 cells/mm² at 12 months postoperatively, corresponding to an ECD decrease of 58 (±6)% as compared to preoperative values. Average best-corrected visual acuity increased from finger counting before surgery to 20/60 (logMar 0.5) at 12 months after 3/4-DMEK and remained stable up to 24 months postoperatively. All corneas remained clear at the last available follow-up.

CONCLUSION

This case series demonstrates the technical feasibility of 3/4-DMEK in eyes with pseudophakic bullous keratopathy in the presence of a GDD tube. The absence of a donor DM and donor cells above the silicone tube excludes direct tube contact with the graft. Longer term studies are needed to show the effect of this modified graft pattern and dimensions on transplant survival.

Advances in corneal graft rejection

PURPOSE OF REVIEW

Immune rejection after corneal transplantation is a major risk for graft failure. We aim to summarize recent advances in the understanding and management of graft rejection.

RECENT FINDINGS

Immune rejection remains the leading cause of graft failure in penetrating keratoplasty (PKP). While ABO blood type and sex match between donor and recipient may reduce rejection, human leucocyte antigens class II matching in a randomized study did not reduce the risk of rejection in high-risk PKP. Compared with PKP, deep anterior lamellar keratoplasty, descemet stripping automated endothelial keratoplasty, and descemet membrane endothelial keratoplasty have lower immune rejection rates of 1.7-13%, 5-11.4%, and 1.7-2.8%, respectively, based on long-term (5 years and more) studies. Whether immune rejection is a major risk factor for graft failure in these lamellar keratoplasties is unclear. While there have not been major advances in the systemic management of graft rejection, topical nonsteroid agents such as tacrolimus and anti-vascular endothelial growth factor have shown promise in high-risk cases.

SUMMARY

Immune rejection remains the leading cause of graft failure in PKP. Lamellar keratoplasties have significantly lower rejection rates compared with PKP. The significance of rejection in the failure of lamellar grafts warrants further investigation.

Risk Factors for Repeat Descemet Membrane Endothelial Keratoplasty Graft Failure

PURPOSE

To evaluate repeat Descemet membrane endothelial keratoplasty (re-DMEK) success rates and to identify risk factors for re-DMEK failure.

DESIGN

Retrospective case series.

METHODS

Settings: Institutional.

PATIENTS AND INTERVENTIONS

A chart review was performed, including all eyes with primary DMEK failure that underwent re-DMEK between 2013 and 2019 at the Toronto Western Hospital and the Kensington Eye Institute (Toronto, Ontario, Canada) and had at least 6 months of follow-up.

MAIN OUTCOME MEASURE

Predicting factors for re-DMEK outcome.

RESULTS

Of 590 consecutive DMEK surgeries, 40 eyes (6.7%) were identified for having a secondary DMEK surgery after primary DMEK failure. Etiologies for primary DMEK were Fuchs endothelial corneal dystrophy (32.5%), pseudophakic bullous keratopathy (35%), previous failed graft (27.5%), and other indications (5%). Fifty-five percent of the cohort were categorized as having a complicated anterior segment including 11 eyes with previous glaucoma surgery, 7 eyes post-penetrating keratoplasty, 4 eyes post-Descemet stripping automated endothelial keratoplasty, 3 eyes peripheral anterior synechia, 3 eyes previous pars plana vitrectomy, 2 eyes aphakia, and 1 eye each with aniridia, anterior chamber intraocular lens, and iris-fixated intraocular lens. Re-DMEK failure was documented in 12 eyes (30%) of the entire cohort. The risk factor for re-DMEK failure was the presence of a complicated anterior segment (P = .01, odds ratio = 17.0 [95% confidence interval: 1.92-150.85]), with 50% re-DMEK failure rate in this subgroup.

CONCLUSION

Re-DMEK is a viable option for cases of primary DMEK failure, especially for eyes with Fuchs endothelial corneal dystrophy as the indication for primary DMEK without other ocular morbidities; however, eyes categorized with a complicated anterior segment had high re-DMEK failure rates.</ABSTRACT>.

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

PURPOSE

Vitrectomized eyes pose a technical challenge when performing endothelial keratoplasty (EK). The aim of the study was to compare outcomes of Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK) in complex eyes undergoing pars plana vitrectomy (PPV) prior to or during surgery.

METHODS

This retrospective study included consecutive eyes that underwent pars plana infusion-assisted DMEK or pull-through DSAEK which underwent PPV prior to or during the EK at a tertiary center. Included were eyes with at least 1-year follow-up. The main outcome measures were best-corrected visual acuity (BCVA) and serious adverse events.

RESULTS

Fifty-two eyes (n = 52) with a mean follow-up time of 24.6 ± 7.4 months were included. Both groups were similar in terms of baseline characteristics although the DMEK group had a significantly larger proportion of Fuchs' patients (p = .009). There was no significant difference in postoperative logMAR BCVA between groups at each visit (p > .05 for all). There was a significantly higher proportion of overall serious adverse events (50.0% versus 15.4%, p = .02), retinal detachments (19.2% versus 0.0%, p = .05) and cystoid macular edema (23.1% versus 0.0%, p = .02) following DMEK. Graft detachment occurred more often following DMEK (53.9% versus 11.5%, p = .001) with no significant difference in rebubbling rates (23.1% versus 11.5%, p = .27).

CONCLUSIONS

A significant and similar improvement in BCVA was achieved following DMEK and DSAEK in complex vitrectomized eyes. Patients should be advised regarding the higher rates of potential serious complications associated with a pars plana infusion DMEK in this situation.

Graft detachments in endothelial keratoplasty

Graft detachment is the most common complication of endothelial keratoplasty. With the ongoing advancements in the field of endothelial keratoplasty, our understanding of risk factors of graft detachments and its management has been evolving. Various prevention measures have been described in literature including presoaking the donor graft, anterior chamber tamponade, venting incisions, sutures to prevent dislocation of graft. Management of a detached graft involves secondary interventions such as rebubbling, suturing and regrafts. In this review, we discuss graft detachment in different types of endothelial keratoplasty techniques including Descemet stripping endothelial keratoplasty, Descemet stripping automated endothelial keratoplasty and Descemet's membrane endothelial keratoplasty; with emphasis on incidence, risk factors, preventive measures and their management.

Corneal endothelial dysfunction: Evolving understanding and treatment options

The cornea is exquisitely designed to protect the eye while transmitting and focusing incoming light. Precise control of corneal hydration by the endothelial cell layer that lines the inner surface of the cornea is required for optimal transparency, and endothelial dysfunction or damage can result in corneal edema and visual impairment. Advances in corneal transplantation now allow selective replacement of dysfunctional corneal endothelium, providing rapid visual rehabilitation. A series of technique improvements have minimized complications and various adaptations allow use even in eyes with complicated anatomy. While selective endothelial keratoplasty sets a very high standard for safety and efficacy, a shortage of donor corneas in many parts of the world restricts access, prompting a search for alternatives. Clinical trials are underway to evaluate the potential for self-recovery after removal of dysfunctional central endothelium in patients with healthy peripheral endothelium. Various approaches to using cultured human corneal endothelial cells are also in clinical trials; these aim to multiply cells from a single donor cornea for use in potentially hundreds of patients. Pre-clinical studies are underway with induced pluripotent stem cells, endothelial stem cell regeneration, gene therapy, anti-sense oligonucleotides, and various biologic/pharmacologic approaches designed to treat, prevent, or retard corneal endothelial dysfunction. The availability of more therapeutic options will hopefully expand access around the world while also allowing treatment to be more precisely tailored to each individual patient.