Rate and Localization of Graft Detachment in Descemet Membrane Endothelial Keratoplasty

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.

Risk factors for early graft detachment requiring rebubbling in Descemet membrane endothelial keratoplasty with imported pre-cut donor tissues

Graft detachment is a common and significant complication in Descemet membrane endothelial keratoplasty (DMEK). We investigated the risk factors of graft detachment requiring rebubbling after DMEK using imported pre-cut donor tissues. The medical records of 48 patients who underwent DMEK for Fuchs' endothelial dystrophy (FED) or bullous keratopathy (BK) at Seoul National University Hospital were retrospectively reviewed. Donor, recipient, and surgical factors were evaluated using univariate and multivariate logistic regression models. Graft detachment requiring rebubbling occurred in 17 (32.7%) eyes. The detachment group exhibited older recipient age (p = 0.006), higher prevalence of diabetes (p = 0.001), and a higher proportion of FED (65%, p = 0.003). Notably, the detachment group demonstrated a significantly lower postoperative 2-h intraocular pressure (IOP) (p = 0.002) and a greater proportion of eyes with IOP <20 mmHg (p < 0.001). Older recipient age (OR 1.08, 95% CI 1.02-1.17), diabetes (OR 23.8, 95% CI 2.61-217), FED surgical indication (OR 6.19, 95% CI 1.74-22.0), lower postoperative 2-h IOP (OR 1.21, 95% CI 1.06-1.38), and postoperative 2-h IOP <20 mmHg (OR 14.0, 95% CI 1.64-119) were associated with increased odds of graft detachment. According to multivariate logistic regression, lower postoperative 2-h IOP (OR 1.23, 95% CI 1.02-1.47) and postoperative 2-h IOP <20 mmHg (OR 25.1, 95% CI 1.05-602) increased the risk of graft detachment. Lower postoperative 2-h IOP, particularly below 20 mmHg, may increase the risk of graft detachment, and diabetes in recipients may pose a higher risk of graft detachment after DMEK.

Rebubbling and graft failure in Descemet membrane endothelial keratoplasty: a prospective Dutch registry study

AIMS

To identify risk factors for rebubbling, and early graft failure after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

In this prospective registry study, all consecutive DMEK procedures registered in the Netherlands Organ Transplant Registry were assessed (n=752). Univariable and multivariable analysis was performed using logistic regression. The effect of rebubbling on endothelial cell density was analysed using a linear mixed model.

RESULTS

144 of 752 (19%) eyes underwent rebubbling. Rebubbling was successful in 101 eyes (70%). In eyes that underwent rebubbling, the graft failure rate was significantly higher than eyes that did not undergo rebubbling (30% vs 9%, respectively; OR: 4.28, 95% CI 2.72 to 6.73, p<0.001). In multivariable analysis, independent risk factors for rebubbling were surgical complication (OR: 2.28, 95% CI 1.20 to 4.33, p=0.012) and older recipient age (OR: 1.04 (per increase of 1 year), 95% CI 1.01 to 1.07, p=0.003). Risk factors for developing graft failure within 3 months were transplant before 2016 (OR: 3.32, 95% CI 1.87 to 5.90, p<0.001), and surgical complication (OR: 2.93, 95% CI 1.42 to 6.04, p=0.004). Throughout the study period, rebubbling and early graft failure were inversely related. Eyes that underwent rebubbling showed significantly lower endothelial cell densities at 3, 6 and 12 months compared with eyes that did not undergo rebubbling (all p<0.001).

CONCLUSIONS

This Dutch registry study identified independent risk factors for DMEK graft detachment leading to rebubbling, namely recipient age and surgical complication, and early graft failure, namely transplantation before 2016 and surgical complication. Rebubbling was associated with significantly higher endothelial cell loss in the first year after surgery.

The need of rebubbling in case of small graft detachments after Descemet Membrane Endothelial Keratoplasty (DMEK)

Purpose

To investigate the need of rebubbling for small graft detachments after Descemet Membrane Endothelial Keratoplasty (DMEK).

Methods

In this retrospective study we evaluated 111 eyes from 111 patients that showed graft detachment after DMEK surgery and have achieved graft adherence by injection of air or 20% sulfur hexafluoride (SF6) to the anterior chamber (rebubbling group; n = 57) or by spontaneous adherence without intervention (control group; n = 54) at final examination. Subgroups in terms of the maximum height and in terms of the detachment area in relation to graft area were formed. Outcome measures were the increase in best-corrected visual acuity (BCVA) and the decrease in central corneal thickness (CCT) from the measurement before DMEK to six months after surgery and postoperative endothelial cell density.

Results

BCVA increased in the rebubbling group and the control group, the difference being 0.22 logMAR, p = 0.048. For eyes with a maximum height less than 500  µm, the increase of BCVA was 0.39 ± 0,36 logMAR in the control group and 0.62 ± 0,53 logMAR in the rebubbling group, p = 0.045. There was no difference of statistical significance of BCVA between both groups regarding the detachment area of less than 20% in relation to graft area. The mean decrease in CCT and postoperative endothelial cell density showed no significant difference between the rebubbling group and the control group.

Conclusion

Compared to spontaneous graft adherence, a rebubbling shows no beneficial effect on the clinical outcome for small detached DMEK grafts. Rebubbling does not decrease postoperative endothelial cell density.

Predictive factors of graft detachment and rebubbling after descemet membrane endothelial keratoplasty

PURPOSE

To identify risk and predictive factors associated with the need of rebubbling in the eye of patients who underwent a descemet membrane endothelial keratoplasty (DMEK).

METHODS

The records of patients who underwent DMEK were retrospectively analyzed. Data regarding comorbidities, intraoperative characteristics, and postoperative treatments or complications were collected. The central corneal thickness (CCT) was measured by optical coherence tomography before and the day after DMEK. Univariate and multivariate analyses were performed.

RESULTS

Of the 333 DMEK, rebubbling was performed in 119 cases (36%). Preoperative subepithelial fibrosis and a history of penetrating keratoplasty (PK) were associated with significantly more graft detachment [OR of 3.55 (2.02-6.32; P < 0.001) and 5.89 (2.00-21.86; P = 0.003), respectively]. A decreased CCT the day after surgery reduced by 5.7-fold the risk of rebubbling (sensitivity/specificity of 0.42/0.93). Conversely, a 20% increase in the CCT the day after surgery increased by 4.5-fold the risk of rebubbling (sensitivity/specificity of 0.42/0.91).

CONCLUSION

Variation of the CCT could be used as a predictive factor of rebubbling after DMEK. Patients with a 20% increase of CCT the day after surgery are at higher risk of graft detachment. Conversely, a reduced CCT the day after the surgery is associated with a reduced risk of rebubbling. Subepithelial fibrosis and history of PK were also identified as risk factors for rebubbling. Those predictive factors may help develop a customized approach for patients undergoing DMEK surgery.

'Posture-Less' DMEK: Is Posturing After Descemet Membrane Endothelial Keratoplasty Actually Necessary?

PURPOSE

To evaluate the clinical results of Descemet membrane endothelial keratoplasty (DMEK) without any intraoperative or postoperative posturing.

DESIGN

Retrospective, noncomparative, and interventional case series.

METHODS

One hundred thirty-four (134) consecutive eyes of 101 patients requiring DMEK for any cause of endothelial failure were included. Descemet membrane endothelial keratoplasty was performed with an intraoperative inferior PI. After unscrolling and centration of the graft, the anterior chamber was near completely filled with 20% SF6. After filling the eye with gas there was no intraoperative tamponade time, and patients did not posture postoperatively. Main outcome measures were: graft detachment rate, rebubbling rate, primary and secondary failure rates, rejection rate, intraoperative and postoperative complications, and visual acuity 3 and 12 months after surgery.

RESULTS

Five of 134 (3.7%) developed graft detachment greater than one-third of the graft area, and 19 of 134 (14.2%) developed graft detachment less than one-third of the graft area. A rebubble procedure was performed in 19 of 134 (14.2%); of those, the average number of rebubbling procedures performed was 1.13 (range, 1-2). Primary failure occurred in 6 of 134 (4.5%).Twelve-month graft survival occurred in 122 of 134 eyes (91.0%), with secondary failure within the first 12 months accounting for failure of 6 of 134 (4.5%). Nine of 134 (6.7%) cases had a recorded episode of endothelial rejection. The average time for rejection episode was 9.5 months (range, 1-20 months) after surgery.

CONCLUSIONS

A total of 134 'posture-less' DMEKs did not suffer very high rates of graft detachment, rebubbling, or other postoperative complications, even with immediate erect posturing after surgery.

Identification of the preoperative and perioperative factors that predict postoperative endothelial cell density after Descemet membrane endothelial keratoplasty: A retrospective cohort study

Low postoperative endothelial-cell density (ECD) plays a key role in graft failure after Descemet-membrane endothelial keratoplasty (DMEK). Identifying pre/perioperative factors that predict postoperative ECD could help improve DMEK outcomes. This retrospective study was conducted with consecutive adult patients with Fuchs-endothelial corneal dystrophy who underwent DMEK in 2015–2019 and were followed for 12 months. Patients underwent concomitant cataract surgery (triple-DMEK) or had previously undergone cataract surgery (pseudophakic-DMEK). Multivariate analyses assessed whether: patient age/sex; graft-donor age; preoperative ECD, mean keratometry, or visual acuity; triple DMEK; surgery duration; surgical difficulties; and need for rebubbling predicted 6- or 12-month ECD in the whole cohort or in subgroups with high/low ECD at 6 or 12 months. The subgroups were generated with the clinically relevant threshold of 1000 cells/mm². Surgeries were defined as difficult if any part was not standard. In total, 103 eyes (95 patients; average age, 71 years; 62% women) were included. Eighteen eyes involved difficult surgery (14 difficult graft preparation or unfolding cases and four others). Regardless of how the study group was defined, the only pre/perioperative variable that associated significantly with 6- and 12-month ECD was difficult surgery (p = 0.01, 0.02, 0.05, and 0.0009). Difficult surgery also associated with longer surgery duration (p = 0.002). Difficult-surgery subgroup analysis showed that difficult graft dissection associated with lower postoperative ECD (p = 0.03). This association may reflect endothelial cell loss due to excessive graft handling and/or an intrinsic unhealthiness of the endothelial cells in the graft that conferred unwanted physical properties onto the graft that complicated its preparation/unfolding.

Recovery of Contrast Sensitivity After Descemet Membrane Endothelial Keratoplasty

PURPOSE

To study the change in contrast sensitivities in eyes with Fuchs endothelial dystrophy and bullous keratopathy after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

In this prospective study, 50 pseudophakic eyes of 50 patients who received DMEK surgery at the Charité-Universitätsmedizin Berlin were included. Visual acuity; contrast sensitivity using OPTEC 6500 at spatial frequencies of 1.5, 3, 6, 12, and 18 cycles/degree in photopic and mesopic light with and without glare; central corneal thickness (CCT); and anterior and posterior corneal aberrations were measured preoperatively and at 3 and 12 months postoperatively.

RESULTS

Best-corrected visual acuity (preoperative 0.67 ± 0.46 and after 12 months 0.19 ± 0.16 LogMAR, P < 0.001) and photopic and mesopic contrast sensitivities with and without glare improved significantly, whereas CCT decreased significantly (preoperative 677 ± 114 μm, after 12 months 527 ± 29 μm, P < 0.001). Preoperative CCT correlates significantly with preoperative photopic contrast sensitivity (correlation coefficient -0.462, P = 0.002), and postoperative total anterior aberrations correlates with postoperative photopic contrast sensitivity (correlation coefficient -0.361, P = 0.006).

CONCLUSIONS

Photopic and mesopic contrast sensitivities, especially with glare, are impaired in patients with Fuchs endothelial dystrophy and bullous keratopathy. The extent of the corneal thickening seems to mainly influence the contrast sensitivity preoperatively. DMEK surgery improves the contrast sensitivity significantly. However, higher postoperative anterior corneal aberrations limit the postoperative contrast sensitivities.

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.

Impact of Re-bubbling after Descemet Membrane Endothelial Keratoplasty on Long-term Results

Purpose/Aim of the study: Graft detachment after DMEK can be treated easily with an additional air injection - re-bubbling. The aim of our study was to investigate the effect of a re-bubbling on the postoperative outcome.Materials and Methods: In this retrospective, comparative, cohort study we included eyes from patients that underwent DMEK surgery. A graft detachment was diagnosed by slit-lamp examination and OCT scan. All eyes were divided into three groups: no re-bubbling, one re-bubbling, more than one re-bubbling. We analyzed the visual acuity, endothelial cell density and rate of graft failure.Results: In 163 of 463 eyes (35.2%) a re-bubbling was performed (119 eyes 1 re-bubbling, 44 eyes more than one re-bubbling). Visual acuity improved significantly in all groups. After controlling for donor age, reason for surgery, time of cultivation of the graft and preoperative visual acuity, no difference in the visual acuity was seen at any point of follow-up. All patients showed a significant reduction in endothelial cell density 1 month after DMEK. Controlling for donor age, reason for surgery, type of surgery (DMEK-only or DMEK combined with cataract surgery) and the time of cultivation of the graft, the difference in endothelial cell density at 1 month post-surgery between no re-bubbling and one re-bubbling was 157 cells/mm² (95% CI 2-310, p = .047) and between no re-bubbling and more than one re-bubbling 504 cells/mm² (95% CI 267 - 741, p < .001). The difference in endothelial cell density remained over the course of follow-up. Twenty patients (4.3%) developed a graft failure during postoperative follow-up. Controlling for donor age, reason for surgery and the time of cultivation of the graft, we did not find any difference in the risk of graft failure between re-bubbling categories.Conclusions: Re-bubbling increased the risk for an endothelial cell loss, but did not influence the postoperative visual acuity and the rate of graft failure.

Use of topical anaesthesia and peribulbar anaesthesia in Descemets membrane endothelial keratoplasty

INTRODUCTION

In instances where peribulbar anaesthesia (PBA) cannot be used, Descemet membrane endothelial keratoplasty (DMEK) surgery can be performed under topical anaesthesia (TA). We evaluated subjective pain and post-operative outcomes of DMEK surgeries performed under PBA and TA.

METHODS

Sixty pseudophakic patients without history of ocular comorbidities underwent DMEK surgery under either PBA or TA. PBA was performed with a single injection of 6 mL Prilocaine Hydrochloride 2% in combination with 1500 I.U. hyaluronidase. For TA, patients were given 0.4% Oxybuprocaine eye drops followed by a 2% Lidocain Hydrochloride-Gel and an intraoperative injection of a 2% Lidocaine Hydrochloride solution into the anterior chamber. All surgeries were performed by the same surgeon. Subjective pain was measured using a visual analog scale (VAS). Secondary outcomes (BCVA, duration of surgery, endothelial density, rebubbling rate) were recorded during a follow-up period of 3 months.

RESULTS

The mean subjective pain of patients in the PBA group was 1.27 (95% CI 0.87-1.68) and 1.64 (95% CI 1.15-2.21) in the TA group. The mean duration of surgery was 402 s (95% CI 356-448) in the PBA group and 427 s (95% CI 371-483) in the TA group, p = 0.477. No major differences were observed in BCVA, endothelium density and rebubbling rate between the two groups. Anaesthesia-related side effects were more frequent in the PAB group than in the TA group.

CONCLUSION

Although levels of subjective pain are lower under PBA than under TA, in selected patients without ocular comorbidities TA can achieve levels of pain acceptable for DMEK surgery.

"Mouse Sign" on Optical Coherence Tomography of Detached Endothelial Graft Indicates Graft Inversion

Purpose:

To report the mouse-like configuration of detached endothelial keratoplasty graft observed on optical coherence tomographic imaging after pre-Descemet's endothelial keratoplasty (PDEK).

Case Report:

Three eyes of 3 patients who underwent PDEK and had graft detachment in the initial postoperative period of <2 weeks were examined. Fourier domain optical coherence tomography was performed in all eyes. All 3 patients had partial graft detachment with the detached region involving the central and inferior cornea. One end of the graft formed a thick convex scroll detaching outward, downward, and upward, and the other end was attached to the edematous cornea forming the ‘mouse’ configuration. The graft was inverted, and rebubbling failed in all 3 eyes. Graft exchange was required.

Conclusion:

Mouse sign in OCT imaging indicates the possibility of an inverted graft and predicts unsuccessful rebubbling. Graft exchange is required in such eyes.

Influences on rebubble rate in Descemet's membrane endothelial keratoplasty

Purpose

Descemet’s membrane endothelial keratoplasty (DMEK) is a minimally invasive partial corneal transplant procedure used in patients with failing endothelial membranes. This study aims to identify those factors which influence the need for a rebubble of the corneal graft.

Methods

A total of 94 eyes that received DMEK between March 2014 and January 2016 at Vance Thompson Vision were used in the study. Demographic and graft data were collected from the patients and donors, and perioperative statistics of the procedures. A logistical regression was used to compare eyes that did and did not require a rebubble.

Results

Among those characteristics that were included (patient age/sex, donor age/sex, death to processing time, donation to surgery time, death to procurement time, specular cell count density, burping procedure, postoperative day 1 intraocular pressure [IOP], and postoperative week 1 IOP, concurrent phacoemulsification, and how well the Descemet graft was centered), only a lower specular cell count density of the corneal graft, and a graft that was not well-centered correlated with needing a rebubble due to partial graft detachment (p=0.021) and (p=0.023), respectively.

Conclusion

An increased specular cell count density may allow for better placement of the corneal graft by allowing for better unfolding in DMEK procedures. A well-centered graft may decrease postoperative complications by increasing adherence. Additionally, postoperative management of IOP may not affect the rebubble rate, and therefore should be left to the discretion of the provider to determine whether it is necessary.

Rebubbling in Descemet Membrane Endothelial Keratoplasty: Influence of Pressure and Duration of the Intracameral Air Tamponade

PURPOSE

To explore the impact of intracameral air tamponade pressure and duration on graft attachment and rebubbling rates.

DESIGN

A prospective, interventional, nonrandomized study.

METHODS

setting: Department of Ophthalmology, Charité - Universitätsmedizin Berlin.

STUDY POPULATION

One hundred seventeen patients who underwent Descemet membrane endothelial keratoplasty (DMEK).

OBSERVATION

Intraocular pressure (IOP) at the end of the surgery, immediately after filling the anterior chamber with air, categorized into low (<10 mm Hg), normal (10-20 mm Hg), and high (>20 mm Hg), and the time until partial removal of the air.

MAIN OUTCOME MEASURES

Rebubbling rates and endothelial cell density over a 3-month follow-up period analyzed by a multivariable Cox regression model and an analysis of covariance model.

RESULTS

Thirty-two patients required a rebubbling (27% [95% CI 19%-35%]). Nine patients required more than 1 rebubbling (7% [95% CI 3%-12%]). Compared with normal IOP, lower (HR 8.98 [95% CI 1.07-75.41]) and higher IOP (HR 10.63 [95% CI 1.44-78.27]) increased the risk of requiring a rebubbling (P = .006). Independent of the IOP, an air tamponade duration beyond 2 hours reduced the risk of rebubbling (HR 0.36 [95% CI 0.18-0.71, P = .003]). One month after surgery, the mean endothelial cell loss was 13% (95% CI 2%-25%) and 23% (95% CI 17%-29%) in the group with air tamponade duration of below and above 2 hours, respectively (P = .126). At 3 months after surgery, it was 31% (95% CI 17%-42%) and 42% (95% CI 32%-52%) in the respective groups (P = .229).

CONCLUSIONS

A postsurgical air tamponade of at least 2 hours with an IOP within the physiological range could help to reduce rebubbling rates.

Descemet stripping automated endothelial keratoplasty versus descemet membrane endothelial keratoplasty: a meta-analysis

PURPOSE

To evaluate the efficacy and safety of descemet stripping automated endothelial keratoplasty (DSAEK) compared with descemet membrane endothelial keratoplasty (DMEK).

METHODS

Databases including PubMed, EMBASE, and Cochrane Library were searched to find studies that compared DSAEK and DMEK outcomes. Efficacy parameters were the postoperative best-corrected visual acuity (BCVA) and spherical equivalent (SE). Safety parameters were postoperative endothelial cell loss (ECL), air injection (rebubbling), graft failure, graft rejection, and high intraocular pressure (IOP). Results from last visit were pooled for the analyses because the follow-up ranged from 3 to 24 months.

RESULTS

A total of 7 trials including 433 eyes were selected for this meta-analysis. BCVA was reported in all 7 studies, ECL% and rebubbling rate were reported in 6, and the remaining outcomes were reported in only 3 or 2 studies. Postoperative logMAR BCVA was significantly better for DMEK than that for DSAEK (P < 0.00001). More patients achieved the postoperative BCVA ≥ 20/25 and 20/20 in DMEK group than that in DSAEK (P > 0.001), whereas the proportion of patients whose postoperative BCVA ≥ 20/40 and the amount of SE did not differ statistically (P = 0.32 and P = 0.50, respectively). The DSAEK group has a significantly lower frequency of rebubbling than the DMEK group (P < 0.0001). The postoperative ECL%, graft failure, graft rejection, and high IOP were comparable between the 2 groups (all P values >0.05).

CONCLUSIONS

Our meta-analysis suggests that DMEK provided better visual outcomes with similar safety when compared to DSAEK. Given the limited sample size, further investigations are needed to validate these findings.