Descemet's Membrane 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.

Predictive factors of long-term visual outcomes after primary Descemet's membrane endothelial keratoplasty (DMEK): retrospective study.

To determine predictive factors of higher levels of best-corrected visual acuity (BCVA) in the long-term after primary Descemet's membrane endothelial keratoplasty (DMEK). Retrospective, single-surgeon case series of 129 successful primary DMEK eyes without graft failure and with a minimum postoperative follow-up of 12months. Mixed effect model for repeated measurements (MMRM) analysis was performed to determine recipient, donor, surgical and postoperative factors associated with BCVA ≤ 0.10 logMAR (≥ 20/25 Snellen). After primary DMEK, there was a statistically significant improvement in BCVA with a global reduction in logMAR BCVA (p < 0.00001). There was also a global tendency towards increasing proportion of eyes with BCVA ≤ 0.10 logMAR at all time points (p < 0.00001), from 1.6% before DMEK to 64.4% in eyes with more than 5years of F-U. Absence of retinal disease was associated with a decrease of 0.10 logMAR in postoperative BCVA after primary DMEK, maintaining constant the rest of variables (p < 0.001). The variables age (OR 0.960), postoperative time (OR 1.083), preoperative BCVA ≥ 0.375 logMAR (OR 0.162) and indication for DMEK (OR 5.412) were included in the predictive MMRM model of BCVA ≤ 0.10 logMAR. Primary DMEK is associated with statistically and clinically significant improvement in BCVA that occur early in the postoperative period and are continuous over time. Eyes with retinal comorbidities have increased risk of worse postoperative BCVA after DMEK. Younger recipient age, Fuchs' dystrophy eyes and eyes with better preoperative BCVA are more likely to achieve postoperative BCVA ≤ 0.10 logMAR.

Severe Corneal Flattening After Endothelial Keratoplasty: Collagen Compaction Syndrome.

The purpose of this study was to present a case series of patients with extreme corneal flattening after uneventful endothelial keratoplasty (EK): collagen compaction syndrome. Four patients (2 men, 2 women, mean age 64.8 ± 11.8 years) underwent successful EK after a period of chronic corneal edema (4-7.5 months): 3 received Descemet membrane endothelial keratoplasty after unsuccessful Descemet stripping only for Fuchs dystrophy and 1 received Descemet automated endothelial keratoplasty after prolonged pseudophakic bullous keratopathy. All patients developed significant corneal flattening, affecting their vision and inducing a large hyperopic refractive outcome, best-corrected visual acuities ranging from 20/40 to 20/200. Chronic corneal edema may result in severe corneal flattening after EK. Preoperative duration of stromal edema might affect the outcome of EK and should, therefore, be considered in the timing of surgery. In cases of dense focal edema, including post-Descemet stripping only surgery, rescue treatment at week 8 should be considered.

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.

A 32-Year-Old Male with Corneal Hydrops

Case Presentation: A 32-year-old male with a history of left eye keratoconus presented to the emergency department with left eye pain and blurry vision for two days. Out of concern for corneal hydrops, ophthalmology was consulted, and the diagnosis was confirmed. Per ophthalmology recommendations, the patient was started on hypertonic saline and prednisolone eye drops and referred to a corneal specialist. Discussion: Corneal hydrops is characterized by stromal edema caused by leakage of aqueous humor due to rupture of Descemet membrane. This case describes a patient with a keratoconus deformity who developed corneal hydrops.

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.

Ten-Year Follow-Up After Descemet Membrane Endothelial Keratoplasty.

To examine clinical results up to 10 years after Descemet Membrane Endothelial Keratoplasty (DMEK) and Triple-DMEK. Prospective study including 201 eyes, of which 54 eyes [38 DMEKs and 16 Triple-DMEKs; Fuchs endothelial dystrophy (n = 45), pseudophakic bullous keratopathy (n = 9)] reached the minimum follow-up of 5 years and were followed up for up to 10 years. We evaluated best-corrected visual acuity (BCVA, logarithm of the minimum angle of resolution [logMAR]), endothelial cell density (ECD, cells/mm2), minimal central corneal thickness (CCT, μm), central retinal thickness (μm), rebubbling, graft survival and re-DMEK rate, chamber angle alterations, and incidence of glaucoma. Fifty-four eyes had a 5-year and 37 eyes an 8- to 10-year follow-up. Mean follow-up was 94.4 ± 12.1 months. Best-corrected visual acuity increased from 0.6 ± 0.3 logMAR to 0.1 ± 0.2 logMAR at 6 months (P ≤ 0.001) and was 539 ± 54 μm at long term. Endothelial cell density decreased from 2488 ± 320.9 (donor) to 980.1 ± 437 cells/mm2 with an average ECD loss/year of 4% and did not correlate with BCVA. Central corneal thickness decreased from 596.9 ± 82.2 μm to 498.6 ± 24.3 μm at 12 months (P ≤ 0.001) and remained stable (P = 1.000). Mean rebubbling rate was 0.3 ± 0.5/eye and did not correlate with BCVA. Eight eyes (14.8%) received at least 1 rebubbling. Primary graft failure/rejection rate was 1.5%/0% within the first postoperative year, and secondary graft failure rate was 12.4% at 7 years. Eight eyes (preoperative n = 3, de novo n = 5) had open-angle glaucoma without chamber angle changes (14.8%, P ≤ 0.001). Although ECD decreases continuously in the long-term follow-up, excellent visual acuity can be preserved 10 years after DMEK and Triple-DMEK. The final outcome can be estimated 6 months after surgery.

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...

Complications after Gonioscopy-Assisted Transluminal Trabeculotomy in glaucoma treatment - literature review.

Glaucoma is a disease that leads to optic nerve damage and irreversible loss of the visual field. Gonioscopy-assisted transluminal trabeculotomy (GATT) is a minimally invasive glaucoma surgery technique, where the surgeon opens the trabecular network and Schlemm's canal to improve the outflow of the aqueous humor. This method has shown efficacy in reducing intraocular pressure in patients with primary and secondary glaucoma. GATT has gained popularity due to its minimally invasive nature, compatibility with cataract surgery and relatively low cost. Despite its advantages, the procedure can be associated with many complications such as hyphema, intraocular pressure spikes and corneal edema. In rare cases, it can lead to Descemet's membrane detachment or cystoid macular edema. The success of GATT procedure mostly depends on the surgeon's skill and experience, but also on the patient's risk factors, including age and preoperative intraocular pressure levels. Further studies are required to understand long outcomes and identify the patients, who may be at higher risk of complications.

Long-term efficacy and safety of ab externo canaloplasty in the Polish Caucasian population with open-angle glaucoma: A 3-year retrospective study.

This study aimed to assess the effectiveness and safety of ab externo canaloplasty over a 3-year follow-up period in Polish Caucasian patients with glaucoma. This retrospective study of a cases series was conducted at the Department of Ophthalmology Medical University of Bialystok, Poland. Primary outcome measures were intraocular pressure and medication burden. Secondary outcome measures were best corrected visual acuity, retinal nerve fiber layer thickness, visual field test results, endothelial cell density, intraoperative and postoperative complications, and additional glaucoma surgery. The study group consisted of 160 eyes diagnosed with early to-moderate primary open-angle glaucoma and treated with ab externo canaloplasty from 2014 to 2020. The criteria for qualified and complete success were intraocular pressure < 18 mmHg or ≥ 20% reduction in intraocular pressure from baseline with or without antiglaucoma medications, respectively. After surgery, the mean intraocular pressure decreased from 19.23 ± 4.33 to 14.52 ± 3.79 mmHg, which constituted a 36.7 ± 7.8% reduction compared to the baseline value. The number of medications decreased by two at the end of the study period (from 2.69 ± 1.05 to 0.32 ± 0.75). Complete and qualified success were achieved in 58.7% and 68.7% of the patients, respectively, at the end of follow-up. An incomplete cannulation of Schlemm's canal was the most common intraoperative complication, occurring in 32 eyes (20%). The most frequent postoperative complications were hyphema, Descemet's membrane detachment, and a transient increase in intraocular pressure. Additional surgical procedure was required in seven cases (4.4%). In 16 patients (10%), medical treatment was re-administered. Overall, our findings suggest that ab externo canaloplasty is a good option for Polish Caucasian patients with primary open-angle glaucoma. It reduces intraocular pressure and has a low postoperative complication rate. Additional glaucoma surgery or re-administration of medications is required if the target intraocular pressure is unsatisfactory.

Excimer Laser-Assisted Deep Anterior Lamellar Keratoplasty Versus Penetrating Keratoplasty for Patients With Keratoconus: A Retrospective Analysis From the Homburg Keratoconus Center.

To evaluate the outcome of excimer laser-assisted deep anterior lamellar keratoplasty (Exc-DALK) and penetrating keratoplasty (Exc-PKP) for keratoconus (KC). We included 123 eyes and compared the outcome of 30 eyes undergoing big-bubble Exc-DALK after stromal debulking (G1) against a matched group of 83 eyes undergoing Exc-PKP (G2) in our department. G2 was created after performing a pseudorandom stratified bootstrapping of our PKP database starting with 2802 surgeries with removal of any bias. Main outcomes included best corrected visual acuity (BCVA), spherical equivalent (SE), tomographic changes, and endothelial cell density (ECD). Data were compared preoperatively, postoperatively with 2 double-running cross-stitch sutures according to Hoffmann [2 and 10 months postoperatively (T1 and T2)], after first suture removal [15 months postoperatively (T3)], and after final suture removal [26 months postoperatively (T4)]. Preoperatively, all parameters were comparable without significant differences. At T1, G1 showed significantly better BCVA (P = 0.01), lower SE (P = 0.04), lower anterior and posterior topographic astigmatism (ATA and PTA, P < 0.01), lower maximal keratometry (P = 0.02), and lower central corneal thickness (P < 0.01). At T2, G1 showed significantly better BCVA (P = 0.04), lower PTA (P < 0.01), and higher ECD (P < 0.01). At T3, G1 showed significantly lower ATA (P = 0.01) and PTA (P < 0.01) and higher ECD (P = 0.02). At T4, G1 showed significantly lower PTA and higher ECD (P < 0.01) but no significant difference in BCVA (P = 0.07). Exc-DALK provided faster visual rehabilitation and represented an endothelial cell-sparing method compared with Exc-PKP. After final suture removal, Exc-DALK showed noninferior outcomes compared with Exc-PKP if the graft was placed on naked Descemet membrane.

Analysis of factors influencing refractive error in Fuchs eyes undergoing Descemet membrane endothelial keratoplasty triple procedure

PurposeTo evaluate the accuracy of current intraocular lens (IOL) formulas and identify factors influencing mean error in eyes undergoing Descemet membrane endothelial keratoplasty (DMEK) triple procedure, that is, DMEK combined...

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.

Descemet Membrane Endothelial Keratoplasty Graft Preparation Using the Liquid Bubble Technique with Subtrabecular Hydrodissection: A Retrospective Real-Life Study

Background: Techniques for the preparation of grafts for Descemet membrane endothelial keratoplasty (DMEK) can be classified into those that involve the manual dissection of the Descemet membrane (DM) and those that use an injection of a liquid or a gas to achieve a separation of the DM from the posterior corneal stroma. The purpose of this study was to evaluate the efficiency of the liquid bubble technique. Methods: The success rate of the technique was calculated retrospectively using the operating reports. Video files for each graft preparation were retrieved and the time, number of injections, and number of injections sites required for the hydrodissection were measured. The number of cases in which a manual dissection of the Descemet membrane was necessary was recorded. Information on donor age and graft preservation time were retrieved from the eye bank file. Results: In 58 cases, the success rate was 98.3%. In the 28 procedures where a video was available, the median time for hydrodissection was 4.4 min. The median number of injection sites was 2, with a median number of injections of 3.5. Manual dissection as a rescue technique was performed in 25% of cases, with one case resulting in graft tears. The mean graft diameter was 7.6 mm. The mean donor age was 66 years, and the mean graft storage time was 22 days. Conclusions: The liquid bubble technique can be a fast and valuable choice for DMEK graft preparation, especially in centers where the tissue is prepared in the operating theater.

Incidence of Descemet Membrane Detachment after Phacoemulsification Cataract Surgery in a Sample of Iraqi Patients at Ibn Al-Haitham Teaching Eye Hospital

Incidence of Descemet Membrane Detachment after Phacoemulsification Cataract Surgery in a Sample of Iraqi Patients at Ibn Al-Haitham Teaching Eye Hospital

Prospective In Vivo Confocal Microscopy of the Central Cornea in Terrien Marginal Degeneration.

To analyze central corneal in vivo confocal microscopy (IVCM) in Terrien marginal degeneration (TMD). An observational prospective case-control study. Ten Finnish patients with TMD from a tertiary referral center were compared with 10 age- and sex-matched healthy volunteers. Seven patients had bilateral TMD. Age, anterior segment optical coherence tomography, extent of thinning in clock hours, grade of microdots, and stage of TMD were analyzed. According to Süveges and Wang classification, the median stage of TMD was 2 (range, 2-3) and 2 (range, 2-6), respectively. Twelve (71%) of 17 eyes with clinical TMD showed corneal thinning at all clock hours. The median age at the time of examination was 70 years (range, 28-81), and the median time from diagnosis 8.8 years (range, 6.0-15.2). By IVCM, the epithelium, subepithelial nerve plexus, and endothelium were intact in all eyes. The anterior stroma showed bilateral hyperreflective dots in the central cornea beneath the subepithelial nerve plexus in all eyes, and larger patches were detected in the posterior stroma anterior to Descemet membrane; both were invisible by anterior segment optical coherence tomography. As compared with controls, the grade of anterior microdots increased faster with age before the age of 65, and that of posterior stromal patches was higher. Two patients additionally had bilateral hyperreflective needle-like deposits in the anterior and midstroma. By IVCM, TMD is characterized regardless of clinical laterality by bilateral microdots in the central corneal stroma. They might be a supporting diagnostic criterion and alone could suggest subclinical disease.

Validation of a French Version of the Visual Function and Corneal Health Status Instrument and Correlation With Vision and Glare Measurements in Fuchs Endothelial Corneal Dystrophy.

To validate a French version of the Visual Function and Corneal Health Status (V-FUCHS) instrument in Fuchs endothelial corneal dystrophy (FECD) and to correlate questionnaire scores with objective measurements of best-corrected visual acuity (BCVA) and intraocular straylight. The original V-FUCHS 15-item instrument was designed to assess VA and glare in patients with FECD. It was translated from English to French and back translated to English by independent translators. The questionnaire was administered on 2 occasions (4 weeks apart), and BCVA, modified Krachmer grade, and straylight were measured. Construct validity, internal consistency, test-retest reliability, and predictive validity were assessed. A total of 159 subjects, aged 41 to 86 years, were prospectively recruited from July 2019 to October 2020 and classified into 6 groups: mild, moderate, or advanced FECD; unilateral or bilateral Descemet membrane endothelial keratoplasty for FECD; and healthy controls (n = 35). Construct validity was confirmed by item response theory model. Cronbach alpha demonstrated excellent internal consistency (VA: 0.91, glare: 0.88), and intraclass correlations showed good test-retest reliability (VA: 0.75 and glare: 0.82). Significant correlations were observed between both VA and glare factors and the modified Krachmer grade, BCVA, and straylight. The proposed French version of the V-FUCHS instrument provides a valid and reliable tool for the assessment of visual disability in patients with FECD. This questionnaire bridges the gap between self-reported FECD symptoms and objective clinical measurements, which may prove useful to optimize the timing of surgery and to assess postoperative improvement in symptoms.

EndoArt®: results in patients with glaucoma drainage devices

EndoArt® (Eye Yon Medical, Ness Ziona, Israel) is anovel artificial corneal inner layer transplant and an innovative treatment alternative for patients at high risk for graft failure after posterior lamellar corneal transplantation (EK). We present the initial results of the EndoArt® implantation in patients with glaucoma drainage devices (GDD). In this study 12eyes with GDD were retrospectively evaluated. All had ahigh risk of transplant rejection in cases of EK (previous other glaucoma surgery in addition to GDD, n = 8, condition following Descemet membrane endothelial keratoplasty, DMEK, n = 9, uveitis, n = 2, or synechiae, n = 2). The EndoArt® was secured with agas bubble and one to three holding sutures. The preoperative and postoperative best spectacle-corrected visual acuity (BSCVA) and central corneal thickness (CCT) were determined. The need for additional gas injections (rebubbling) was analyzed. Octafluoropropane (C3F8) 12% was used in nine patients and sulfur hexafluoride (SF6) 20% in three patients as anterior chamber tamponade to ensure adhesion of the EndoArt®. At least one rebubbling was necessary in four eyes. The preoperative BSCVA was 1.6 (± 0.5) logMAR and significantly improved to 1.1 (± 0.6) logMAR after 12weeks (p = 0.028). The preoperative CCT was 719 µm ± 145.7, which significantly decreased to 622.4 µm ± 174.9 after six weeks (p = 0.004) and to 591.7 µm ± 190.8 after 12weeks (p = 0.096). In one eye, the prosthesis was explanted due to a suspected fibrotic remodelling of the cornea following multiple previous DMEKs. EndoArt® led to asignificant improvement in BSCVA and reduction in CCT; however, there was ahigh rebubbling rate in patients with GDD. In high-risk patients, the use of EndoArt® may be advantageous in avoiding graft failure after EK.

Carbon Footprint of Fluorinated Gases Used in Endothelial Keratoplasty.

The purpose of this study was to examine the direct impact on carbon emissions attributed to the use of fluorinated gases in endothelial keratoplasty (EK) procedures using gas tamponade and to evaluate the respective carbon footprint of different gas delivery systems used in EK procedures. In this retrospective, single-center environmental impact study, all corneal procedures using fluorinated gases between January 2021 and January 2024 at the Royal Liverpool University Hospital were reviewed and included. The CO2 equivalent emissions were calculated based on the mass of each fluorinated gas used, following the guidelines of the Intergovernmental Panel on Climate Change. Of 357 total procedures (160 Descemet membrane endothelial keratoplasty [44.8%], 118 Descemet stripping automated endothelial keratoplasty [33.1%], and 79 rebubbling [22.1%]), single-use sulfur hexafluoride (SF6) canisters were used in 278 (77.9%) procedures. SF6 canisters used in corneal transplantation emitted nearly 1.5 tons of CO2 over 3 years. The 30-mL canisters emitted twice the CO2 per GBP compared to SF6 15-mL canisters and 4 times that of C2F6 or C3F8 15-mL canisters. Fluorinated gas use in corneal transplantation has a significant environmental impact, which can be reduced by the use of smaller single-use canisters with lower carbon footprint, although manufacturing and disposal concerns remain. Our findings advocate for a more environmentally conscious approach to EK, favoring the use of smaller, more cost-efficient canisters and considering air as an alternative tamponade where possible.

Innovative surgical treatment approaches for endothelial dysfunction : Descemet stripping only (DSO) and endothelial cell injection

Currently, due to arising number of patients Germany and many other countries experience alarge deficit of donor eyes for posterior lamellar keratoplasty procedures in the treatment of corneal endothelial diseases. To address this unmet need there is an ongoing investigation of treatment modalities which do not rely on donor tissue or enable clinicians to treat more patient eyes per donor eye. The authors introduce apromising approach for both treatment principles. First, the technique of Descemet stripping only (DSO) is detailed, in which acentral part of the Descemet's membrane including the endothelium is surgically removed without replacement with donor tissue. This then allows endothelial cells from the periphery of the cornea to migrate into the central area and can reduce corneal opacification and swelling. As arepresentative technique of the second group, the authors introduce endothelial cell injection, in which human corneal endothelial cells are cultivated in vitro and then, after removal of the diseased endothelium, injected into the anterior chamber of the recipient's eye to form anew and healthy endothelium. This is supported by injection of Rho kinase inhibitors and aface-down positioning of the patient after surgery. It is postulated that endothelial cell injection could possibly enable clinicians to treat up to 300 patient eyes with the tissue generated from 1 donor eye. Whether and how these novel approaches will become established in Europe remains to be seen.