Graft Detachment Research Articles

Bagel sign and how to avoid it in DMEK surgery.

To provide a detailed description of the recommended surgical technique for gas injection during Descemet's Membrane Endothelial Keratoplasty (DMEK) surgery and highlight intraoperative sign that emerged in case of fluid retention in the interface. Gas injection recommended surgical technique is 2 steps procedure using a 1 ml syringe: the first step consists in injecting centrally to the graft and very slowly a bubble of gas smaller than the DMEK graft size, the second step, after checking the absence of fluid interface (no bagel sign), consists in enlarging the gas bubble to the desired filling. Bagel sign allows surgeons to look for interface fluid and correct for potential issues leading to graft detachment. The recommended surgical technique for gas injection also may help to prevent fluid retention in the interface and reduce the risk of graft detachment. Detecting a fluid interface retention at the end of DMEK surgery through iOCT or simply looking for the bagel sign may help to prevent post-operative complications.

Graft detachment rates in surgeon-cut and pre-cut tissue for DSAEK transported in different mediums.

To analyse graft detachment rates after Descemet stripping automated endothelial keratoplasty (DSAEK) using surgeon-cut grafts and pre-cut grafts transported in different mediums. A retrospective study of graft detachment rates including 265 surgeries (240 patients) performed between 2019 and 2023. The DSAEK grafts were either surgeon-cut (n = 135) or pre-cut and transported in a dextran-containing medium (n = 82) or in a dextran-free medium (n = 48). All surgeries were performed by a single surgeon (I.G.). The surgeries were categorised according to whether the recipients' eyes had, or did not have, factors associated with an increased risk of graft detachment. Detachment rates were compared for all patients receiving the different kinds of graft, and only for those without risk factors. A significantly higher detachment rate was found among patients receiving pre-cut grafts transported in a dextran-containing medium (32.9%), compared to surgeon-cut grafts (14.1%, p = 0.002), and pre-cut grafts transported in a dextran-free medium (6.3%, p = 0.002) for all recipients (those with and without risk factors for graft detachment). When analysing recipients without risk factors for graft detachment, the detachment rate was still significantly higher with pre-cut tissue transported in a dextran-containing medium (26.9%), compared to surgeon-cut tissue (8.3%, p = 0.002) and pre-cut tissue transported in a dextran-free medium (3.6%, p = 0.01). The use of pre-cut DSAEK tissue transported in a dextran-containing medium significantly increases the risk of graft detachment requiring re-bubbling.

Efficacy of Sutureless Scleral Fixation of One-Piece T-Shaped Haptic Intraocular Lens in Maintaining Anterior Chamber Stability During Descemet Membrane Endothelial Keratoplasty in Vitrectomized Eyes: Leak Test and Iris Diaphragm Reconstruction

Objectives: This study aimed to describe the outcomes of a staged procedure combining Descemet membrane endothelial keratoplasty (DMEK) and sutureless scleral fixation (SSF) of a one-piece intraocular lens (IOL) in a case series. Co-performing endothelial keratoplasty (EK) and SSF is associated with intraoperative and postoperative complications such as graft deployment difficulties, air migration, graft detachment, and IOL opacification or tilt, all of which are evaluated in this study. Methods: This is a retrospective observational case series. Clinical data were collected from eight eyes of eight patients who underwent DMEK for endothelial failure and had previously received an SSF with one-piece IOL following complete vitrectomy. During DMEK surgery, an air leak test was conducted to check for air migration into the posterior chamber. If instability was detected, pupilloplasty was performed. Intraoperative and postoperative data, including DMEK graft unfolding time, were collected. Corrected Distance Visual Acuity (CDVA), refraction, endothelial cell density (ECD), central corneal thickness (CCT), intraocular pressure (IOP), and complications were recorded over a 12-month follow-up period. Results: We performed pupilloplasty in four patients (50%). The median CDVA improved from preoperative 0.85 logMAR (range: 0.60 to 1.00) at baseline to 0.18 logMAR (range: 0.10 to 0.70, p = 0.012) at 12 months. The median refraction value changed significantly from −1.00 to −0.50 at 12 months. The median percentage reduction in ECD after 12 months was 33.4% (range 30 to 40). The median baseline CCT was 689 μm (range: 651 to 701) at baseline visit and 541.5 μm (range: 525 to 591, p = 0.008) at 12 months. The median IOP was reduced significantly during follow-up. The median graft unfolding time was 6 min (5 to 9). One patient required rebubbling for partial detachment on postoperative day one. No complications occurred within 12 months. Conclusions: The effective compartmentalization of the anterior and posterior chambers in vitrectomized eyes with an SSF one-piece IOL and pupilloplasty can facilitate critical steps of DMEK surgery in complex eyes. Additionally, the air leak test could prove useful in identifying the need for iris-lens diaphragm reconstruction.

Off-Centered DMEK Grafts: Impact and Resolution.

The aim of this study was to assess the outcomes of off-centered Descemet membrane endothelial keratoplasty (DMEK) grafts compared to descemetorhexis. This is a retrospective case series of DMEK procedures conducted between June 2022 and July 2023 with postoperative graft decentration, characterized by a gap between the graft and descemetorhexis edge. Eight eyes of 8 patients met the inclusion criteria. The average gap between the descemetorhexis edge and DMEK graft was 911.2 μm (range 306-1468). The resulting focal peripheral edema overlying the gap resolved in all cases, with a median time of 3 months. Best-corrected visual acuity improved from 0.49 (±0.26) logarithm of the minimum angle of resolution to 0.01 (±0.02) logarithm of the minimum angle of resolution at 12 months (P = 0.003). Central corneal thickness decreased from 646.5 (±177.8) μm to 473.7 (±29.6) μm at 12 months (P = 0.05). One eye, in the overlapped area of host-donor Descemet membranes, had small peripheral partial graft detachment less than one-third of graft surface area. No eyes required graft rebubbling. A larger descemetorhexis to DMEK gap showed a trend toward longer resolution times (P = 0.06). Focal edema in the inferonasal periphery took longer to recover compared with the nasal position (P = 0.01). Larger descemetorhexis to DMEK gaps did not significantly influence the longitudinal visual acuity trend (P = 0.75). Decentered DMEK, characterized by a gap between the graft and descemetorhexis edge, leads to focal stromal edema that diminishes over time, with no impact on final visual acuity.

Influence of surgeon learning on outcomes in new ophthalmic procedures: quantified nationwide evidence in endothelial corneal transplantation

AimsTo investigate the impact of surgeon learning on endothelial keratoplasty (EK) procedure outcomes.MethodsA prospective nationwide registry study of EK grafts in patients aged at least 21 years with Fuchs endothelial...

Cataract surgery with endothelial keratoplasty.

This review aims to provide an updated summary of the combined approach of cataract surgery with endothelial keratoplasty (EK), addressing key considerations, including intraocular lens (IOL) choice and calculation, decision between sequential and triple EK, and modifications in surgical techniques and postoperative management. Advances in imaging techniques (Scheimpflug tomography and anterior segment optical coherence tomography) have improved the ability to detect subclinical corneal edema, aiding in surgical decision-making for EK. Recent studies comparing sequential and triple-EK indicate that both methods yield similar visual outcomes. Though triple-EK offers quicker recovery, it may have higher complication rates. The use of gases like SF6 and C3F8 for anterior chamber tamponade is evolving, with conflicting findings on their efficacy in preventing graft detachment. Furthermore, IOL selection remains crucial, as hyperopic refractive surprises are common, and hydrophilic lenses should be avoided owing to the risk of opacification after EK. The combination of cataract surgery with EK has emerged as an effective treatment for patients with corneal endothelial diseases and cataract. Careful preoperative evaluation, appropriate IOL selection, and advances in surgical techniques contribute to better outcomes, although patient-specific factors must guide the choice between sequential and triple-EK procedures.

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.

Cataract surgery with corneal endothelial pathology

Abstract: It is not uncommon for Fuch’s endothelial corneal dystrophy (FECD) patients to present with a co-existent cataract. Surgeons are often faced with a choice between simultaneous and staged corneal and cataract surgery. Descemet’s membrane endothelial keratoplasty (DMEK) has been found to have better visual outcomes as compared to Descemet’s stripping endothelial keratoplasty (DSEK) and penetrating keratoplasty and is currently the preferred surgery for FECD. Endothelial cell count and pachymetry cutoffs were earlier used for decision-making. Various other investigations such as Scheimpflug imaging and confocal microscopy are now used to prognosticate the outcome when performing cataract surgery only. Triple DMEK has the advantage of a definite treatment in a single sitting. Whereas, a staged approach with DMEK followed by cataract surgery has a better visual outcome. This is due to variable refractive changes in the cornea post-DMEK or DSEK that can lead to inaccurate intraocular lens (IOL) power calculation. Even though the graft detachment rates and rebubbling rates have been found to be comparable in triple DMEK versus a staged surgery, in view of increasing patient demands and expectations for a spectacle-independent outcome, a staged surgery is now preferable. Conventionally, surgeons favored the use of only monofocal lenses; however, the use of premium IOLs, especially extended depth of focus lenses, is now increasing. In this review, we will discuss the various advantages and disadvantages of a simultaneous and staged approach and pearls on decision-making in FECD with cataracts.

Assessment of Corneal Graft Outcomes in a Murine Model of Endothelial Keratoplasty.

Objectives: In this study, we establish a protocol for evaluating the outcomes of endothelial keratoplasty, including graft survival, rejection, or failure. Additionally, we also evaluate the alloimmune response in graft recipients. Methods: We performed EK using C57BL/6 (allogeneic) and BALB/c (syngeneic) as donors and BALB/c mice as recipients. Slit-lamp examination and optical coherence tomography were performed for clinical evaluations for 16 weeks post-procedure. Criteria for the assessment of corneal opacity were established and the animals were graded weekly. Additionally, we assessed corneal endothelial cell density by harvesting the corneas and staining with zonula occludens-1 (ZO-1). Lastly, lymph nodes were collected, and CD4+ T cells were MACS-sorted and co-cultured with syngeneic or allogeneic antigen-presenting cells (APCs) to assess the IFN-γ expression levels by alloreactive Th1 cells (ELISPOT) in response to the direct (donor) or indirect (host) pathways of sensitization. Results: We observed graft failure in four animals, including irreversible corneal opacity, graft detachment, and anterior synechiae in the first four weeks. The remaining animals were graded between 0 and 5 as per the established criteria. The total and graft corneal thickness and endothelial cell density progressively worsened with a higher grade of corneal opacity. The direct allosensitization of Th1 cells was significantly higher in mice with a higher grade of corneal opacity. At 16 weeks follow-up, the grafts remained stable with low opacity scores in syngeneic EK recipients; however, the opacity scores were higher and variable in allogeneic EK recipients. Conclusions: These findings establish a standardized protocol to assess the graft outcomes in a murine model of EK. Furthermore, we delineate the underlying immunological pathway that contributes to the immune-mediated rejection of grafts in this model.

Bubble-graft coverage after Descemet Membrane Endothelial Keratoplasty depending on gaze angle.

In Descemet Membrane Endothelial Keratoplasty (DMEK) a gas bubble is usually used to attach the graft to the host cornea. In this study, we observed the bubble size and bubble-graft coverage at different gaze angles following DMEK. This observational prospective study analyzed 465 images of patients who underwent an uneventful DMEK. Intraoperatively, the anterior chamber was filled up to 90% of its volume with a 20% Sulfur Hexafluoride (SF6) gas-air mixture. Postoperatively, the bubble was photographed daily in different gaze angles ranging from a supine position (0°) to an upright position (90°) and a slightly inclined position (105°). The primary outcomes were bubble-graft coverage and bubble diameters depending on the gaze angle and time after DMEK. The highest bubble-graft coverage was achieved at a 0° gaze angle at all times of measurement. In the first 48 h after DMEK, the mean bubble-graft coverage was over 85% at a gaze angle between 0° and 45°. Starting 72 h after DMEK, the graft coverage declined at all gaze angles. The graft coverage at a 0° gaze angle was 88.61 ± 10.90% after 96 postoperative hours, while the graft coverage was below 85% at all other gaze angles. Our clinical results provide novel insight into variation in bubble-graft coverage as a function of gaze angle and may be used to aid in patient counselling for appropriate body positioning following DMEK to prevent early graft detachment. Maintaining supine positioning seems to be most advantageous starting 48 h after DMEK.

Blocking Air in the Filtering Bleb: Effects on Graft Adhesion After Descemet's Stripping Automated Endothelial Keratoplasty.

To evaluate the outcome of Descemet's stripping automated endothelial keratoplasty (DSAEK) with "blocking air" in the filtering bleb in patients with previous trabeculectomy. In total, 299 eyes in 283 patients who underwent DSAEK were retrospectively reviewed. Endothelial graft adhesion, intraocular pressure (IOP), and air volume in the anterior chamber with (group A) or without (group B) a filtering bleb were compared between the groups. Group A was divided into two subgroups according to the presence (group A1) or absence (group A2) of air in the filtering bleb; the same three factors were compared between the subgroups. The graft detachment rate was significantly higher in group A (14.3%) than in group B (6.5%) (p = 0.04). IOP was significantly lower in group A than in group B before surgery (p = 0.01), at the end of surgery (p = 0.04), at three hours (p < 0.001), and one week postoperatively (p = 0.02). The graft detachment rate did not significantly differ between groups A1 and A2. There were no differences in IOP at each follow-up time, whereas there was a statistically significant increase in IOP from the preoperative measurement to the end of surgery in group A1 (21.0±7.0 mmHg) compared with group A2 (14.2±8.6 mmHg) (p = 0.02). The presence of blocking air in the filtering bleb helps ensure increased IOP during the early postoperative period but had no significant effect on graft detachment rates.

Determining Risk Factors for Detachment After Endothelial Keratoplasties: Nine-Year Review of a Single Institution.

To determine roles of patient history, donor tissue characteristics, tissue preparation methods, and surgeon technique for graft detachment requiring rebubbling after Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) procedures. Retrospective analysis of all eyes undergoing first-time DSAEK or DMEK at the study institution between 2013 and 2022. Data were collected regarding recipients' history, donors' medical history, tissue preparation methods, intraoperative details, and postoperative clinical outcomes. Multivariate statistical analysis was conducted to identify risk factors for graft detachment necessitating rebubbling. Of 1240 eyes meeting inclusion criteria, 746 (60.2%) underwent DSAEK, and 494 (39.8%) underwent DMEK. DSAEK procedures had 12.5% rebubbling rate, whereas DMEK procedures had 18.4% rebubbling rate (P = 0.005). Sub50-DSAEK (<50 μm) grafts had 16.0% rebubble rate, whereas sub100-DSAEK (51-99 μm) and >100 μm DSAEKs had rebubble rate of 9.9% and 9.5%, respectively (P = 0.006). Significant risk factors for DSAEK graft detachment included history of retinal surgery (OR = 2.59), preloaded tissue (OR = 2.70), forceps insertion (OR = 2.33), use of sub50-DSAEK lenticules versus sub100-DSAEK (OR = 2.44) and >100 μm DSAEK (OR = 2.38) lenticules, and donor history of noninsulin-dependent diabetes mellitus (OR = 4.18). DMEK risk factors included recipient history of cancer (OR = 2.51) and use of higher SF6 gas concentration (OR = 1.09). Although rebubbled DMEK eyes had comparable refractive outcomes to nonrebubbled eyes (P >0.05), rebubbled DSAEK eyes had worse refractive outcomes at all time points (P < 0.05). Graft detachments in DSAEK and DMEK are influenced by various factors, including donor tissue characteristics, tissue preparation, and surgical technique. Identifying and understanding these factors can potentially improve postoperative outcomes.

Microkeratome versus manually dissected donor tissue for Descemet stripping endothelial keratoplasty: A randomized prospective study.

To compare the visual outcomes, postoperative complications, and graft asymmetry between precut and manually dissected donor tissues for Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet stripping endothelial keratoplasty (DSEK) procedures, respectively. Seventy eyes of 70 patients undergoing DSEK/DSAEK at a tertiary eyecare center in eastern India were included in this prospective randomized control study. The 70 eyes were divided equally into two groups. Group A (n = 35) and Group B (n = 35) underwent DSEK and DSAEK procedures, respectively. the operating surgeons prepared the manually dissected corneal grafts using lamellar dissectors. the eye bank technicians prepared the precut corneal grafts using a microkeratome. The patients were investigated postoperatively after 1 day, 1 week, 1 month, 3 months, and 6 months. The data were compared for visual outcomes [uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical and cylindrical refraction, and spherical equivalent], incidence of postoperative complications, and pachymetry. The mean age was 56.5 (±17.8) years, and the male-to-female ratio was 1.3:1. The most common indications were pseudophakic bullous keratopathy (45.71%, 32/70), failed graft (32.86%, 23/70), and Fuchs' endothelial corneal dystrophy (10%, 7/70). The indications for surgery (P = 0.732) and donor (P = 0.258) and host pachymetry (P = 0.986) were comparable between both groups. There was no significant difference in change of UCVA, BCVA, and postoperative refraction (mean spherical refraction, P = 0.849; mean cylindrical refraction, P = 0.516; spherical equivalent, P = 0.518) between the two groups. Postoperative complications like graft detachment (P = 0.179), graft failure (P = 0.513), graft infiltrate (P = 0.428), and endophthalmitis (P = 0.493) were higher in the DSAEK group; however, the difference between the groups was insignificant. The graft asymmetry index was higher in DSAEK than in DSEK; the difference was significant till the 1-month follow-up (P = 0.005). The outcome was similar in both groups. Therefore, manual donor dissection can be an alternative for microkeratome-assisted dissection in low-resource centers and countries to achieve good results.

Clinical Outcomes of Repeat Descemet Membrane Endothelial Keratoplasty After Graft Failure.

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

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

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). 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. 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%. 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.

Principal Component Analysis of a Real-World Cohort of Descemet Stripping Automated Endothelial Keratoplasty and Descemet Membrane Endothelial Keratoplasty Cases: Demonstration of a Powerful Data-Mining Technique for Identifying Areas of Research.

Principal component analysis (PCA) is a descriptive exploratory statistical technique that is widely used in complex fields for data mining. However, it is rarely used in ophthalmology. We explored its research potential with a large series of eyes that underwent 3 keratoplasty techniques: Descemet membrane endothelial keratoplasty (DMEK), conventional Descemet stripping automated endothelial keratoplasty (ConDSAEK), or ultrathin-DSAEK (UT-DSAEK). All consecutive DMEK/DSAEK cases conducted in 2016 to 2022 that had ≥24 months of follow-up were included. ConDSAEK and UT-DSAEK were defined as preoperative central graft thickness ≥130 and <130 μm, respectively. Seventy-six patient, disease, surgical practice, and temporal outcome variables were subjected to PCA, including preoperative anterior keratometry, the use of sulfur hexafluoride gas (SF6) versus air for primary tamponade, and postoperative best corrected visual acuity and endothelial cell density. Associations of interest that were revealed by PCA were assessed with the Welch t test or Pearson test. A total of 331 eyes were treated with DMEK (n = 165), ConDSAEK (n = 95), or UT-DSAEK (n = 71). PCA showed that ConDSAEK and UT-DSAEK clustered closely, including regarding postoperative best corrected visual acuity, and were clearly distinct from DMEK. PCA and follow-up univariate analyses suggested that in DMEK, 1) flatter preoperative anterior keratometry (average, K1, and K2) associated with more rebubbling (P = 0.004-0.089) and graft detachment (P = 0.007-0.022); 2) graft marking did not affect postoperative ECD; and 3) lower postoperative endothelial cell density associated with SF6 use (all P > 0.001) and longer surgery (P = 0.005-0.091). All associations are currently under additional investigation in our hospital. PCA is a powerful technique that can rapidly reveal clinically relevant associations in complex ophthalmological datasets.

3D Mapping of the DMEK Detachment Area from OCT Scans of the Anterior Segment of the Eye - Clinical Applications.

Graft detachment is the most common complication after Descemet membrane endothelial keratoplasty (DMEK). To assess the amount of graft detachment, precision is limited when using slit-lamp biomicroscopy. Detachment of DMEK grafts can be assessed automatically on anterior segment optical coherence tomography (AS OCT) images and allows visualization of the area and volume of detachment using 3D maps. This article provides an overview of its applications such as accurately assessing the course of natural graft attachment, identification of potential risk factors for detachment and evaluation of the long-term effect of graft detachment. The 3D map of DMEK detachment may support researchers and clinicians in precise quantification of the area and volume of graft detachment even in large data sets, and the intuitive, fast and reliable evaluation.

Descemet Membrane Endothelial Keratoplasty for Penetrating Keratoplasty

ABSTRACT Background: Descemet membrane endothelial keratoplasty (DMEK) has been utilized more frequently during recent years to treat penetrating keratoplasty (PKP) graft failures. The perioperative evaluation technique of anterior segment optical coherence tomography (AS-OCT) is increasingly significant. Our goal is to discuss DMEK surgical and clinical for subsequent PKP graft failure, along with significant surgical modifications and adjustments in accordance with preoperative assessment utilizing AS-OCT. Materials and Methods: Patients’ records who performed DMEK for PKP failure were retrospectively reviewed. Demographic information, PKP graft size determined by postoperative problems, corneal donor endothelial cell density (ECD), AS-OCT, central pachymetry, visual acuity (VA) evaluated in Snellen units, intraoperative surgical procedure modifications, and postoperative ECD were all included in the data collection. Results: The observation was conducted with 16 patients with 16 eyes, nine males and seven females. The observation period is 18 months. DMEK was performed at an average age of 63. Preoperative AS-OCT was performed on all patients, and based on cases, surgical plans were created. Before processing DMEK, the mean VA is 0.04, and central pachymetry is 685 m. They improved considerably to 0.3 (P value = 0.001) and 542 m (P value = 0.008) at the most recent follow-up. About 93.75% of the grafts were adhered to after the procedure. Late decompensation caused a 6.25% graft failure rate. Graft detachment rates and cases requiring rebubble rates were respectively 18.75%. Conclusion: In DMEK for failed PKP, a good case-specific preoperative assessment by AS-OCT is essential. As a result, it relies on developing a surgical strategy that can improve surgical outcomes, lower the risk of complications, and quicken visual recovery.

Descemet Membrane Endothelial Keratoplasty With and Without Graft Deswelling: A Prospective Clinical Study.

The purpose of this study was to assess whether omission of dextran from corneal organ culture medium alters the outcome of Descemet membrane endothelial keratoplasty. Participation in this single-center, multisurgeon, prospective, randomized, comparative clinical trial was offered to patients scheduled for Descemet membrane endothelial keratoplasty between April 2020 and May 2022. Patients received grafts from corneas deswollen in organ culture medium-containing 6% dextran T-500 or from corneas that were not deswollen. Corrected distance visual acuity (CDVA), graft detachment, central corneal thickness (CCT), and corneal endothelial cell counts were measured at different time points up to 12 months postoperatively. Grafts stored with dextran were transplanted in 92 patients, and grafts stored without dextran were transplanted in 102 patients. Mean donor age and endothelial cell counts did not differ significantly between both groups. Mean (±SD) postmortem time in hours was 23.9 ± 11.8 in grafts that were deswollen and 28.2 ± 13.8 in grafts that were not deswollen (P = 0.02). The groups did not show any significant difference at baseline regarding sex, CDVA, or CCT. In the group with dextran, patients had a mean age of 72.5 ± 9.9 years versus 69.5 ± 8.7 in the group without dextran (P = 0.03). CDVA improved and CCT decreased significantly in both groups. No differences were detected between the groups regarding CDVA, CCT, endothelial cell counts, or rebubbling rates. This study did not detect any evidence that the omission of dextran from organ culture medium negatively affects the outcomes of Descemet membrane endothelial keratoplasty.

Analysis of Graft Detachments and Re-Bubblings After 450 Descemet Membrane Endothelial Keratoplasty Procedures.

To objectify the indication for re-bubbling by analyzing graft detachments (GDs) after Descemet membrane endothelial keratoplasty. In this retrospective monocentric observational study, re-bubbling cases of 450 Descemet membrane endothelial keratoplasties and the percentage of the residual gas filling (RGF) in the anterior chamber on the first postoperative day were collected. The number/location/extent of GDs and the corneal thickness above GDs were analyzed using anterior segment optical coherence tomography. From a total of 450 grafts, 384 (85.3%) had at least a minimal degree GD. One hundred twenty-two of 450 grafts (27.1%) underwent at least 1 re-bubbling. The mean RGF was significantly lower in eyes with GD (67.7 ± 12.6%) than in eyes without GD (74.2 ± 11.3%). GDs occurred most frequently in the inferotemporal quadrant (46.0%). GDs were significantly more likely to require a re-bubbling when the central parts of the graft were affected (94.0% vs. 35.7%). The number of detachments per graft was directly proportional to the re-bubbling rate. The GDs which required a re-bubbling were on average 56 μm higher and 461 μm wider than the untreated ones. The cornea above the GDs that needed a re-bubbling was significantly thicker than above the untreated GDs (mean 988 ± 102 μm vs. 951 ± 99 μm). The RGF seems to be a major influencing factor for graft attachment. The most susceptible location of the GD is inferotemporal. The main factors that need to be investigated to decide if a re-bubbling is required are the number of detachments per graft, their dimensions, whether the central portions of the graft are involved, and the corneal thickness above GDs.