Improving the success rate of human corneal endothelial cell cultures from single donor corneas with stabilization medium.

Main objective of this study was to improve the success rate of human corneal endothelial cell (hCEC) cultures from single donor corneas. We could show that the use of stabilization medium prior to cell isolation may have a positive effect on the success rate of hCEC cultures from single research-grade donor corneas by allowing growth of otherwise possibly not successful cultures and by improving their proliferative rate. hCEC were obtained from corneo-scleral rims of 7 discarded human research-grade cornea pairs. The Descemet membrane-endothelium (DM-EC) sheets of each pair were assigned to 2 experimental conditions: (1) immediate cell isolation after peeling, and (2) storage of the DM-EC sheet in a growth factor-depleted culture medium (i.e. stabilization medium) for up to 6 days prior to cell isolation. hCEC isolated by enzymatic digestion were then induced to proliferate on pre-coated culture plates. The success rate of primary cultures established from single donor corneas were higher for DM-EC sheets kept in stabilization medium before cell isolation. All cultures (7/7) initiated from stabilized DM-EC sheets were able to proliferate up to the third passage, while only 4 out of 7 cultures initiated from freshly peeled DM-EC sheets reached the third passage. In addition, for the 4 successful paired cultures we observed a faster growth rate if the DM-EC sheet was pre-stabilized prior to cell isolation (13.8 ± 1.8 vs 18.5 ± 1.5 days, P < 0.05). Expression of the phenotypical markers Na+/K+-ATPase and ZO-1 could be shown for the stabilized cultures that successfully proliferated up to the third passage.

Spontaneous corneal clearance after graft detachment in DMEK.

Descemet Membrane detachment is a potential complication after Descemet Membrane Endothelial Keratoplasty (DMEK). Here, we present a unique case of a DMEK surgery in a complicated eye that suffered a nearly complete DMEK graft detachment and later a graft opacification with a pseudo-anterior chamber. In Mid-November 2020, a planned DMEK was performed in a 64-year-old male patient due to corneal decompensation. Four months after DMEK, a fibrotic DMEK graft was seen across the anterior chamber with a pseudo-anterior chamber; however, the recipient cornea showed complete clearance with an endothelial cell count of about 1204 cells/mm2 and a best-corrected visual acuity of 20/25. Three months later, we observed a significant opacification of the detached graft, and the best-corrected distance visual acuity decreased to 20/63. We proceeded with the graft removal without performing a second DMEK. Ten months after graft removal, the cornea remained clear with an endothelial cell count of about 510 cells/mm2, and the best-corrected visual acuity was 20/25.

[Descemet membrane endothelial keratoplasty (DMEK): two-year results]. / Queratoplastia endotelial de membrana de Descemet (DMEK): resultados a dos años.

PURPOSE: To report the two-year results of Descemet membrane endothelial keratoplasty (DMEK) for managing corneal endothelial disorders. METHODS: Non-randomized prospective clinical trial. A DMEK was performed in ten patients with Fuchs' endothelial dystrophy or bullous keratopathy. A 3.5 mm clear corneal incision was made and "under air" DM was stripped off from the posterior stroma. A 9.0 mm diameter, organ cultured donor DM roll was inserted into a recipient anterior chamber, positioned into the posterior stroma and secured by completely filling the anterior chamber with air for 30 minutes. RESULTS: Three eyes showed complete detachment of the tissue; this was managed by a secondary Descemet stripping endothelial keratoplasty procedure. The remaining seven eyes had a best corrected visual acuity of >or=0.7 in three eyes (43%) at one month, in five eyes (71%) at six months, and in six eyes (86%) at one and two years. At six months, the endothelial cell density averaged 2039 (+/-373) cells/mm2 (n=7), at one year 1925 (+/-267) cells/mm2 (n=7) and at two years 1730 (+/-400) cells/mm2 (n=6). CONCLUSIONS: DMEK may provide quick and nearly complete visual rehabilitation. Since the donor tissue can be stripped from donor corneo-scleral rims, the procedure may be readily accessible to most corneal surgeons.

[Lamellar keratoplasty. Back to the future?!]. / Lamelläre Keratoplastik. Zurück in die Zukunft?!

In 1840 Mühlbauer was the first to describe a technique for anterior lamellar keratoplasty (LKP). However, in the second half of the twentieth century penetrating keratoplasty (PKP) became the gold standard. Although it is associated with a higher risk for serious complications -- it is technically easier to perform and avoids wound healing reactions in the lamellar interface and thus resulting in better visual acuity. In view of the pathology, replacing all layers of the cornea including healthy parts can be considered therapeutic "overkill" for many corneal graft indications. Several innovative surgical techniques have recently been described which allow the lamellar dissection of recipient and donor cornea with good reproducibility in almost every desired depth. This now allows the recipient endothelium and Descemet's membrane to be selectively replaced or preserved and to avoid formation of an optical barrier in the lamellar interface in eyes undergoing lamellar keratoplasty for optical indications. The most important principal advantage of an anterior LKP -- to minimize the risk of an immune reaction in the graft -- is even more important in tectonic indications. From the large number of variations, the surgical technique, results, and problems with anterior and posterior LKP for optical indications as well as lamellar segment keratoplasty and epikeratoplasty for tectonic indications are discussed.

Standardization of the Descemet membrane endothelial keratoplasty technique: Outcomes of the first 450 consecutive cases.

OBJECTIVES: To evaluate the clinical outcome of the first 450 consecutive cases after Descemet membrane endothelial keratoplasty (DMEK), as well as the effect of standardization of the technique. MATERIAL AND METHODS: Comparison between 3 groups: Group I: (cases 1-125), as the extended learning curve; Group II: (cases 126-250), transition to technique standardization; Group III: (cases 251-450), surgery with standardized technique. Best corrected visual acuity, endothelial cell density, pachymetry and intra- and postoperative complications were evaluated before, and 1, 3 and 6 months after DMEK. RESULTS: At 6 months after surgery, 79% of eyes reached a best corrected visual acuity of≥0.8 and 43%≥1.0. Mean preoperative endothelial cell density was 2,530±220 cells/mm2 and 1,613±495 at 6 months after surgery. Mean pachymetry measured 668±92 µm and 526±46 µm pre- and (6 months) postoperatively, respectively. There were no significant differences in best corrected visual acuity, endothelial cell density and pachymetry between the 3 groups (P > .05). Graft detachment presented in 17.3% of the eyes. The detachment rate declined from 24% to 12%, and the rate of secondary surgeries from 9.6% to 3.5%, from group I to III respectively. CONCLUSIONS: Visual outcomes and endothelial cell density after DMEK are independent of the technique standardization. However, technique standardization may have contributed to a lower graft detachment rate and a relatively low number of secondary interventions required. As such, DMEK may become the first choice of treatment in corneal endothelial disease.

Double vital staining using trypan blue and infracyanine green in macular pucker surgery.

AIMS: To study the clinical properties of double vital staining in premacular fibrosis, facilitating complete removal of all epiretinal tissue. METHODS: In a two step surgery, the epiretinal pucker was removed after staining with trypan blue, whereafter the inner limiting membrane was peeled after staining with infracyanine green. RESULTS: In all 30 patients, a separate epiretinal layer and inner limiting membrane were removed from the macular area. Pathological examination showed different histological properties of the removed layers. An increased visual acuity was measured in 26 patients, and a slightly decreased visual acuity in one patient. CONCLUSION: The described double staining technique could be a novel valuable tool that may help to achieve optimal anatomical and functional recovery after surgery for premacular fibrosis

[Techniques for posterior lamellar keratoplasty through a scleral incision]. / Techniken der posterioren lamellären Keratoplastik über einen skleralen Zugang.

PURPOSE: To describe several techniques for posterior lamellar keratoplasty through a scleral incision, for management of corneal endothelial disorders like pseudophacic bullous keratopathy and Fuchs' endothelial dystrophy, and to report the mid-term clinical results. METHODS: Three techniques have been developed to perform a posterior lamellar keratoplasty procedure through a scleral incision, i.e. to replace the posterior corneal layers while leaving the anterior corneal surface intact and without the use of corneal sutures. In the first technique, a 9.0 mm scleral incision is made to accommodate an intracorneal trephine and spoon-shaped glide to insert a 7.5 mm donor posterior lamellar disc into the anterior chamber. In the second technique, the procedure is performed through a 5.0 mm scleral tunnel incision using microscissors and by folding a 8.5 mm donor posterior disc prior to insertion. In the third technique, a 4.0 mm tunnel incision is made to perform a descemetorhexis in the host cornea, i.e. Descemet's membrane is selectively excised from the recipient eye, and a 9.0 mm donor Descemet's membrane is inserted. In eyes with a minimal postoperative follow-up of 3-5 years ( n=16), we documented the best spectacle corrected visual acuity (BSCVA), keratometry readings, endothelial cell counts, and clinical events. RESULTS: In all cases, the graft adhered to the recipient posterior cornea without suture fixation. In patients without concomitant ocular disease, BSCVA was 0.7-1.0 in all eyes. The astigmatism averaged 2.1+/-0.7 D, endothelial cell counts averaged 2126+/-529 cells/mm(2) at 6 months, 1839+/-473 cells/mm(2) at 12 months, 1418+/-434 cells/mm(2) at 24 months, and 1137+/-420 cells/mm(2) at 36 months. In two patients, an irido-corneal adhesiolysis was performed within days after the procedure. In one patient, residual visco-elastic adherence was present at the donor-to-recipient interface, and a penetrating keratoplasty was performed 1 month postoperation. One patient developed significant interface haze, requiring a penetrating keratoplasty 13 months after the first surgery. CONCLUSION: Posterior lamellar keratoplasty can be an effective surgical technique to manage corneal endothelial disorders. An improved visual acuity can be obtained within the first weeks after surgery, and the visual perfomance of the graft is stable up to 5 years postoperation.

[Standardized Descemet membrane endothelial keratoplasty (DMEK): technique and latest results]. / Standardisierte Descemet-Membran-Endothelkeratoplastik (DMEK) : Technik und aktuelle Ergebnisse.

BACKGROUND: The procedure of posterior lamellar keratoplasty has now become established as first choice therapy for the treatment of corneal endothelial diseases, with Descemet membrane endothelial keratoplasty (DMEK) as the most recent refinement of endothelial keratoplasty techniques. In this study the outcome of 400 consecutive cases after standardized no-touch DMEK was evaluated. METHODS: This was a non-randomized retrospective clinical study of 400 consecutive eyes in 321 patients who underwent standard DMEK. Outcome measures included best corrected visual acuity (BCVA) preoperatively and postoperatively at 1, 3 and 6 months, endothelial cell density (ECD), pachymetry and complications within the first 6 months. In addition two subgroups were analyzed (subgroup I cases 1-200 and subgroup II cases 201-400). RESULTS: At 6 months postoperatively 80 % of all eyes had a BCVA of ≥ 20/25 (≥ 0.8), 44 % of ≥ 20/20 (≥ 1.0) and 14 % of ≥ 20/18 (≥ 1.2). There were no significant differences between the two subgroups. The mean ECD preoperatively was 2,542 (± 217) cells/mm(2) and 6 months postoperatively 1,622 (± 500) cells/mm(2). The mean ECD decrease was 36 % 6 months after DMEK. No difference between the subgroups was noted. In 5 % a re-operation was needed of which 75 % were performed in subgroup I. CONCLUSION: With the standardized no-touch DMEK technique a rapid and nearly complete visual rehabilitation as well as ECD values similar to earlier endothelial keratoplasty techniques can be achieved. Therefore DMEK may become the preferred treatment for corneal endothelial disorders.

What does the future hold for the treatment of Fuchs endothelial dystrophy; will 'keratoplasty' still be a valid procedure?

Fuchs endothelial corneal dystrophy (FECD) is a well recognized corneal disorder characterized by the presence of collagenous warts extending from Descemet membrane (guttae) and endothelial cellular dysfunction due to cell loss and/or degeneration. Because of the characteristic abnormal cell morphology as seen with specular microscopy as well as the limited regenerative capacity in vivo, the endothelial cells were considered to be 'dystrophic'. Hence, FECD is commonly managed by replacement of the endothelium with donor tissue by means of a penetrating or endothelial keratoplasty. The latter procedure has now been refined to the isolated transplantation of a donor Descemet membrane and its endothelium, referred to as Descemet membrane endothelial keratoplasty (DMEK). Unexpectedly, clinical observation made after DMEK seemed to challenge the current concept of the state of the endothelium in FECD; we actually observed an important role for the 'dystrophic' host endothelium in re-endothelialization of the denuded DM, and subsequent corneal clearance. In addition, recent studies regarding the pathophysiology of FECD made us realize that the endothelial cells are not 'dystrophic' per se, but in the course of time may have acquired a dysfunction instead. This paper describes the rationale behind this new concept and based on this, discusses the possibilities for future, less invasive treatment modalities for FECD.

Aclaramiento corneal espontáneo tras desprendimiento del injerto en DMEK / Spontaneous corneal clearance after graft detachment in DMEK

El desprendimiento de la membrana de Descemet es una complicación potencial tras la queratoplastia endotelial de la membrana de Descemet (DMEK, acrónimo en inglés de Descemet membrane endothelial keratoplasty). En este artículo presentamos un caso clínico de una cirugía DMEK en un caso complicado, que presentó un desprendimiento casi completo del injerto y posteriormente una opacificación de este y la formación de una seudocámara anterior. En noviembre del 2020, se realizó una cirugía DMEK a un paciente de 64 años debido a una descompensación endotelial. Tres meses después del DMEK, se observó el injerto desprendido y parcialmente adherido, fibrótico en la cámara anterior y formando una seudocámara anterior. Sin embargo, la córnea se mantuvo totalmente transparente con un recuento endotelial de aproximadamente 1.204 células/mm2 y la agudeza visual con corrección fue 20/25. Tres meses más tarde, se objetivó una opacificación significativa del injerto despegado y la agudeza visual disminuyó a 20/63. Procedimos a la extracción del injerto sin realizar una segunda DMEK. Diez meses más tarde, la córnea permaneció transparente con un recuento endotelial de 510 células/mm2 y la agudeza visual con corrección fue 20/25 (AU)

Descemet Membrane detachment is a potential complication after Descemet Membrane Endothelial Keratoplasty (DMEK). Here, we present a unique case of a DMEK surgery in a complicated eye that suffered a nearly complete DMEK graft detachment and later a graft opacification with a pseudo-anterior chamber. In Mid-November 2020, a planned DMEK was performed in a 64-year-old male patient due to corneal decompensation. Four months after DMEK, a fibrotic DMEK graft was seen across the anterior chamber with a pseudo-anterior chamber; however, the recipient cornea showed complete clearance with an endothelial cell count of about 1204 cells/mm2 and a best-corrected visual acuity of 20/25. Three months later, we observed a significant opacification of the detached graft, and the best-corrected distance visual acuity decreased to 20/63. We proceeded with the graft removal without performing a second DMEK. Ten months after graft removal, the cornea remained clear with an endothelial cell count of about 510 cells/mm2, and the best-corrected visual acuity was 20/25 (AU)

Descemet membrane endothelial keratoplasty (DMEK) for Fuchs endothelial dystrophy: review of the first 50 consecutive cases.

PURPOSE: To evaluate the clinical outcome and complications of Descemet membrane endothelial keratoplasty (DMEK), using Descemet-stripping endothelial keratoplasty (DSEK) as a back-up procedure, in the management of Fuchs endothelial dystrophy. DESIGN: Non-randomised prospective clinical study. METHODS: The first fifty consecutive eyes that underwent DMEK, that is, transplantation of an isolated donor Descemet membrane carrying its endothelium, for Fuchs endothelial dystrophy were evaluated. In all eyes, the best-corrected visual acuity (BCVA) as well as the endothelial cell density (ECD) was measured before and at 6 months after surgery, as clinical outcome parameters. RESULTS: Ten patients required a secondary DSEK for failed DMEK. In the remaining 40 DMEK eyes, 95% had a BCVA of > or = 20/40 (> or = 0.5) and 75% > or = 20/25 (> or = 0.8) at 6 months after surgery. ECD averaged 2618 (+ or - 201) cells/mm(2) before, and 1876 (+ or - 522) cells/mm(2) at 6 months after surgery (n = 35). When the outcomes of DMEK and secondary DSEK procedures were combined, 94% reached a BCVA of > or = 20/40 (> or = 0.5) and 66% > or = 20/25 (> or = 0.8) (n = 47), and ECD averaged 2623 (+ or - 193) cells/mm(2) before, and 1815 (+ or - 578) cells/mm(2) at 6 months after surgery (n = 43). CONCLUSION: With DSEK as a back-up procedure, DMEK may provide relatively quick and complete visual rehabilitation in a majority of patients operated on for Fuchs endothelial dystrophy. Endothelial cell survival may be similar to earlier types of (lamellar) keratoplasty. Early graft detachment was the main complication in this first series of DMEK surgeries for Fuchs endothelial dystrophy.

Floating device for donor corneas in organ culture.

AIM: To introduce a new floating device for donor corneas to avoid accumulation of debris onto the endothelial surface during organ culture and to facilitate handling of the tissue during preservation and surgery. METHODS: From 11 donors, one randomly chosen cornea was stored in organ culture attached to a floating device, while the contralateral cornea was attached to the lid of the phial by a suture ("hanging by suture"). Endothelial cell density (ECD) was evaluated prior to tissue storage and after 2-3 weeks of culture. Furthermore, we compared ECD in a larger group of corneas sent off for transplantation with the device (n = 281) to a historical group of control corneas "hanging by suture" (n = 444). RESULTS: There was no significant difference in ECD between corneas attached to the floating device or "hanging by suture" (n = 11; p > or = 0.1). Similarly, no different ECDs were observed between corneas sent off for transplantation with the device (n = 281) and the historical group of control corneas "hanging by suture" (n = 444) (p > or = 0.1). CONCLUSION: The use of the floating device may not affect tissue quality. Since its introduction, the use of the device has been uneventful and greatly facilitated tissue handling.

Queratoplastia endotelial de membrana de Descemet (DMEK): resultados a dos años / Descemet membrane endothelial keratoplasty (DMEK): Two-year results

Objetivo: Describir los resultados, dos años despuésde realizar una queratoplastia endotelial demembrana de Descemet (DMEK: Descemet membraneendothelial keratoplasty), para el tratamientode alteraciones del endotelio corneal.Métodos: Estudio clínico prospectivo no randomizado.En 10 pacientes con distrofia endotelial deFuchs o queratopatía bullosa, se practicó unaDMEK. A través de una incisión de 3,5 mm en córneaclara, la membrana de Descemet (MD) delreceptor fue desprendida del estroma posterior enpresencia de aire. Un disco de 9 mm de diámetroenrollado de MD donante preservada, fue insertadoen la cámara anterior del receptor, posicionado encontacto con el estroma posterior corneal y aseguradoen su posición mediante el llenado completode la cámara anterior con aire durante 30 minutos.Resultados: Tres ojos mostraron un desprendimientocompleto del tejido donante, por lo que fueronsometidos posteriormente a una queratoplastiaendotelial con «pelado» de la MD (DSEK: Descemet stripping endothelial keratoplasty). En los sieteojos restantes, se observó una agudeza visual mejorcorregida (AVMC) ≥ a 0,7 en 3 ojos (43%) en el primermes, en 5 ojos (71%) a los seis meses, y en seisojos (86%) al primer y segundo años. A los seismeses, la densidad celular endotelial media fue de2039 (DS: 373) cél/mm2 (n=7), al año de 1925 (DS:267 cél/mm2 (n=7) y a los 2 años de 1730 (DS: 400)cél/mm2 (n=6).Conclusión: DMEK podría proporcionar una recuperaciónrápida y casi completa de la visión. Debidoa que el tejido donante puede ser obtenido a partirde anillos córneo-esclerales donantes, el procedimientopodría ser fácilmente accesible para lamayoría de los cirujanos corneales(AU)

Purpose: To report the two-year results of Descemetmembrane endothelial keratoplasty (DMEK)for managing corneal endothelial disorders.Methods: Non-randomized prospective clinicaltrial. A DMEK was performed in ten patients withFuchs’ endothelial dystrophy or bullous keratopathy.A 3.5 mm clear corneal incision was madeand «under air» DM was stripped off from the posteriorstroma. A 9.0 mm diameter, organ cultureddonor DM roll was inserted into a recipient anteriorchamber, positioned into the posterior stroma andsecured by completely filling the anterior chamberwith air for 30 minutes.Results: Three eyes showed complete detachmentof the tissue; this was managed by a secondary Descemetstripping endothelial keratoplasty procedure.The remaining seven eyes had a best correctedvisual acuity of ≥ 0.7 in three eyes (43%) at onemonth, in five eyes (71%) at six months, and in sixeyes (86%) at one and two years. At six months, theendothelial cell density averaged 2039 (±373) cells/mm2 (n=7), at one year 1925 (±267) cells/mm2(n=7) and at two years 1730 (±400) cells/mm2(n=6).Conclusions: DMEK may provide quick andnearly complete visual rehabilitation. Since thedonor tissue can be stripped from donor corneoscleralrims, the procedure may be readily accessibleto most corneal surgeons(AU)