Repeat Descemet Membrane Endothelial Keratoplasty for Failed Primary Descemet Membrane Endothelial Keratoplasty at a Referral Center for Keratoplasty in Spain: DIMOEK Study

Clinical Outcomes of Repeat Descemet Membrane Endothelial Keratoplasty After Graft Failure

PURPOSE

To evaluate the clinical outcomes after repeat Descemet membrane endothelial keratoplasty (DMEK) for technical failure (TF) and secondary graft failure (SGF).

METHODS

Retrospective analysis of 49 eyes that underwent repeat DMEK either for TF (ie, persistent graft detachment, n = 24) or for SGF (ie, late endothelial graft failure, n = 25). Surgery indications for primary DMEK were Fuchs endothelial corneal dystrophy (FECD, 80%) and bullous keratopathy (BK, 20%). Main outcome measures were best-corrected visual acuity (BCVA), endothelial cell density (ECD), corneal backscattering, pachymetry, and graft survival. Outcomes were compared with an age-matched control group of 49 primary DMEK eyes.

RESULTS

Logarithm of the minimum angle of resolution BCVA improved from 0.92 ± 0.6 before to 0.20 ± 0.3 at 1 year after repeat DMEK with better outcomes for eyes with TF than those with SGF (P = 0.046). Donor ECD decreased from 2618 ± 171 cells/mm2 before to 1247 ± 422 cells/mm2 at 1 year postoperatively, with no difference between technical TF and SGF eyes (P > 0.05). One-year BCVA and ECD outcomes were better in the control group than in the repeat DMEK group (P < 0.05). Five-year graft survival probability after repeat DMEK was better for TF than for SGF eyes (100% vs. 75%, P = 0.010) and better for eyes with FECD than BK as primary indication for surgery (92% vs. 65%, P = 0.042).

CONCLUSIONS

Repeat DMEK gives acceptable clinical outcomes especially when performed for TF in the early period after primary DMEK. Long-term graft survival probability after repeat DMEK is comparable to primary DMEK for FECD eyes, whereas BK eyes may show an elevated risk to develop graft failure again.

Trends and Surgeon Variations in Early Regrafts After Endothelial Keratoplasty: Analysis of the National Medicare Data Set

PURPOSE

The aims of this study were to determine national-level trends in early regraft rates and examine patient-level and surgeon-level characteristics associated with early regrafts.

METHODS

This was a retrospective, cohort study. We identified beneficiaries aged 65 years or older in the 2011 to 2020 Medicare carrier claims data set who underwent Endothelial keratoplasty (EK) and subsequently underwent an early regraft. The incidence of early regraft for each year was calculated and patient-level and surgeon-level characteristics associated with regrafts were examined using a multivariable regression model.

RESULTS

Of 114,383 EK procedures, 4119 (3.60%) were followed by an early regraft, with no significant variations in the rates between years ( P = 0.59). Factors associated with higher odds of early regraft were Black compared with White race (OR 1.151; 95% confidence interval (CI) 1.018-1.302) and the highest quartile of income versus the lowest quartile (OR 1.120; 95% CI 1.002-1.252). Factors associated with lower odds were female sex (OR 0.889; 95% CI 0.840-0.942), receiving surgery in a hospital-based outpatient department versus an ambulatory center (OR 0.813; 95% CI 0.740-0.894), and having a surgeon with the highest quartile of annual EK volume versus the lowest (OR 0.726; 95% CI 0.545-0.967). Early regraft rates among surgeons ranged from 0% to 58.8% with a median [interquartile range] of 3.13 [0-6.15].

CONCLUSIONS

We found no significant increases in the early regraft rates over the past decade in the United States. Patient male sex and Black race, ambulatory surgery center-based location of the surgery, and low surgeon EK volume were associated with early regrafts. Substantial surgeon variability in regraft rates may indicate opportunities for improvement through development of best practices on perioperative management and patient counseling.

Descemet’s Membrane Endothelial Keratoplasty for Corneal Endothelial Failure Secondary to Three Types of Phakic Intraocular Lens – Retrospective Study

Purpose

To analyze the outcomes of Descemet's membrane endothelial keratoplasty (DMEK) for corneal endothelial failure secondary to phakic intraocular lens implantation (PIOL) at a reference center for corneal transplantation in Spain.

Design

Retrospective, single-surgeon case series.

Methods

Single-center analysis of patients who underwent DMEK for PIOL-related corneal decompensation between July 2011 and July 2020 with at least 6 months of follow-up postoperatively. Primary outcome was final best-corrected visual acuity (BCVA, logMAR) compared to pre-DMEK BCVA. Secondary outcomes analyzed included post-DMEK refractive spherical equivalent, endothelial cell loss (%ECL), and graft failure.

Results

Sixteen eyes (14 patients) underwent DMEK for PIOL-related corneal decompensation. Mean (SD) time to PIOL explantation was 9.3 (5.0) years, and median (P25-P75) time between PIOL explantation and DMEK surgery was 3 (2-4) months. Median pre-DMEK BCVA was 0.80 (1.08-0.60) logMAR. A statistically significant improvement in BCVA was observed 1 month after DMEK (p = 0.001), and median final BCVA was 0.15 (0.0-0.35) logMAR (p = 0.002). Mean %ECL was 55.6 (18.7) % at 2-year follow-up and 61.7 (11.7) % in eyes with over 4 years of follow-up. Two eyes required re-bubbling (12.5%), one of which ended in primary graft failure (6.2%) and one eye had late endothelial graft failure (LEGF) at 4-year follow-up (1/15 grafts, 6.7%).

Conclusion

In patients with PIOL-related corneal decompensation, DMEK leads to good and clinically significant refractive and visual outcomes in the medium-long term, with a good safety profile. Prospective studies are encouraged to ascertain whether these cases are at increased risk of accelerated endothelial cell loss and LEGF.

Outcomes of cystoid macular edema following Descemet's membrane endothelial keratoplasty in a referral center for keratoplasty in Spain: retrospective study

The aim of this study was to analyze the outcomes of eyes with visually significant cystoid macular œdema (vs-CMO) after Descemet membrane endothelial keratoplasty (DMEK) in a referral center for keratoplasty in Spain. We conducted a retrospective, single-surgeon case series of eyes that developed post-DMEK vs-CMO performed between January 2011 and December 2020. Data collected included: indication for DMEK; biometric data; ocular comorbidities; past medical history; time to detection of vs-CMO after DMEK (T, weeks); best-corrected visual acuity (BCVA, logMAR) and central retinal thickness (CRT, µm) at diagnosis of vs-CMO, after resolution of CMO, and at last follow-up; and management strategy. Main outcomes analyzed were incidence of vs-CMO, improvement in BCVA and CRT after treatment of vs-CMO. Of 291 consecutive DMEK surgeries, 14 eyes of 13 patients (4.8%) developed vs-CMO. Five patients (38.5%) had history of CMO, and 28.6% of eyes had ophthalmic comorbidities. Median (P25-P75) T was 4 (3-10) weeks. Treatment success was observed in 12/13 eyes (92.3%), two of which required second-line treatment. In successful cases (median time-to-resolution 3.0 (2.0-3.5) months), median BCVA improved from 0.60 (0.40-0.80) logMAR to 0.30 (0.15-0.40) logMAR (p = 0.002) after treatment, and median CRT improved from 582.5 (400.0-655.0) µm to 278.0 (258.0-294.0) µm (p = 0.005). In our study, we found a 4.8% rate of post-DMEK vs-CMO, with most cases occurring in the first 3 months after surgery. Good functional and anatomical outcomes are expected in most eyes, without treatment-related complications or implications in graft outcomes. Additional studies are encouraged to determine a standardized protocol for post-DMEK vs-CMO.

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 after PKP and DMEK: What is the Best Option?

Corneal transplantation is the most commonly performed human tissue transplantation procedure worldwide. Due to the large number of grafts, corneal graft failure has become one of the most common indications for corneal transplantation for immunological and non-immunological reasons (e.g. recurrence of underlying disease, high intraocular pressure, grafted guttae, transmitted HSV or CMV infection). The relatively recently developed lamellar grafting techniques have introduced certain potential complications that may lead to graft failure and require approaches other than penetrating keratoplasty for re-grafting. On the other hand, these new lamellar techniques also offer new possibilities for salvaging failed penetrating grafts, with potential advantages over successive penetrating keratoplasties, such as lower intraoperative risks, faster visual rehabilitation and reduced risk of immune reaction. Today, the patient with good healing who is satisfied with his graft before endothelial decompensation, with low astigmatism and no stromal scars, represents the optimal condition for DMEK after PKP. This can also be combined with phacoemulsification (so-called triple DMEK). Otherwise, a penetrating re-keratoplasty with a larger graft (typically excimer laser repeat PKP 8.5/8.6 mm) is performed to treat edema, scars and irregular astigmatism simultaneously. The medical history carries weight in this decision! Re-DMEK in case of graft failure after DMEK and DSAEK does not require any modification of the standard technique and leads to good visual acuity results if performed quickly. If there is clear stromal scarring after multiple (external) DMEKs, PKP can also be considered to rectify the situation. Otherwise causeless recurrent graft failures must suggest herpetic or CMV endotheliitis and, after PCR analysis of the aqueous humour aspirate, be treated appropriately with medication.

Secondary Endothelial Keratoplasty-A Narrative Review of the Outcomes of Secondary Corneal Endothelial Allografts

BACKGROUND

We review the literature on the efficacy and safety outcomes of secondary Descemet stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Literature search of English-written publications up to September 27, 2020 in PubMed database, using the terms "endothelial keratoplasty" in combination with keywords "secondary" or "repeat." In addition, we manually searched the references of the primary articles.

RESULTS

Twenty-seven studies (n = 651 eyes) were retained and reviewed, including 10 studies on repeat DSEK, 8 studies on repeat DMEK, 6 studies of DMEK following DSEK, and 3 studies of DSEK after failed DMEK. All studies reported significant improvement in visual acuity after secondary endothelial keratoplasty (EK). Twelve studies compared visual outcomes between primary and secondary EK, reporting conflicting findings. Sixteen studies reported endothelial cell loss rates after secondary EK, and only 1 study reported significantly increased endothelial cell loss rates compared with primary EK. Allograft rejection episodes occurred in 1.8% of eyes (range, 0%-50%). Six studies compared complication rates between primary and secondary EK eyes, and only 1 study found a higher median number of complications. However, 2 studies reported higher regraft failure rates compared with primary EK eyes.

CONCLUSIONS

Secondary EK is surgically feasible and renders significant visual improvement after failed primary EK, although it is not clear whether visual outcomes and allograft survival are comparable with primary EK, raising the question of whether secondary EK eyes are "low risk" as primary EK eyes. Further larger, prospective studies are encouraged to obtain additional quality data on secondary corneal endothelial allotransplantation.

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>.

Corneal transplantation after failed grafts: Options and outcomes

Corneal transplantation is the most commonly performed human tissue transplantation procedure worldwide. Because of the large number of transplants, corneal graft failure has become one of the most common indications for corneal transplantation. The relatively recently developed lamellar transplant techniques have brought about specific potential complications leading to graft failure that may require different approaches to repeat transplantation other than penetrating keratoplasty. On the other hand, these new lamellar techniques also provide novel ways of rescuing failed penetrating grafts, with potential advantages over successive penetrating keratoplasties, such as reduced intraoperative risks and faster visual rehabilitation. We summarize the incidence and risk factors of graft failure for penetrating and lamellar (stromal and endothelial) corneal transplants and discuss the various surgical alternatives currently available to rescue such failed grafts, with a focus on the reported outcomes and limitations.