Side Of Epithelium Research Articles

DMEK lenticule preparation from donor corneas using a novel ‘SubHyS’ technique followed by anterior corneal dissection

PurposeTo describe a novel submerged hydro-separation (SubHyS) technique followed by anterior corneal dissection to prepare a Descemet endothelial graft (DEG) for Descemet's membrane endothelial keratoplasty from human donor corneas.Methods30 human...

Clusterin and Complement Activation in Exfoliation Glaucoma

The study was done to better understand the biological significance of clusterin co-localization with the exfoliation deposits (XF deposits), and provide insight into a pathogenic mechanism involving activation of the complement system and its pro-inflammatory consequences in patients with exfoliation glaucoma. Exfoliation lens deposits were analyzed by high resolution atomic force microscopy imaging and confocal immunofluorescence. Levels of clusterin and vitronectin, as well as of the complement activation products C3a and soluble C5b-9, were assessed via ELISA. Atomic-force microscopy examination of lenses with exfoliation syndrome (XFS) revealed a dense fibrillar network on the anterior, aqueous-bathed surface of the lens, while the epithelial side displayed no discernible structural features at the same resolution. Clusterin colocalized with XF deposits, demonstrating integral association with the fibrils. Levels of activation-derived complement components C3a and soluble C5b-9, as well as the complement inhibitors clusterin and vitronectin, were found significantly elevated (1.7-fold, P < 0.05; 4.1-fold, P < 0.05; 1.8-fold, P < 0.01; and 3.0-fold, P < 0.01, respectively) in aqueous humor from glaucoma patients with XFS compared to non-XFS glaucoma controls. The data provide compelling evidence for the activation of the complement system in XFS, highlighting the generation of subproducts with potent proinflammatory activity, which are capable of triggering and chronically maintaining levels of subclinical inflammation, suggesting novel targets for therapeutic intervention. The colocalization of clusterin in exfoliation fibrils suggests a failed attempt to prevent tissue accumulation of protein aggregates, as seen in other protein folding disorders, likely due to the abnormal high levels of misfolded proteins overwhelming its chaperone capacity.

The Physiologic Roles of the Subepithelial Platelet-derived Growth Factor Receptor α-positive Cells in the Colon (Am J Physiol Gastrointest Liver Physiol 2013;304:G823-G834)

Platelet-derived growth factors (PDGFs) exist in epithelial cells, endothelial cells and fibroblasts of animals and play roles in cell proliferation, survival and migration.1 It is composed of 4 subtypes (A, B, C and D), and their receptors (PDGFRs) have 2 subtypes (α and β). Platelet-derived growth factor receptor α-positive cells (PDGFRα+ cells) in the gastrointestinal tract is known as fibroblast-like cells. Recently, it is noted, the PDGFRα+ cells in the muscle layers of the gastrointestinal tract are involved in purinergic motor neurotransduction. However, PDGFRα+ cells are distributed at all subepithelial lesion and the physiologic role is not yet established. Recently, Kurahashi et al2 evaluated the distribution in subepithelial cells in the mouse and human colon, and the phenotype and potential role of those cells. They assessed the subepithelial PDGFRα+ cells connected to each other and located just beneath the colonic epithelium, with its pericryptal sheaths from the base to the top of crypts being sparse at the bottom of crypts. Subepithelial α-smooth muscle actin-positive (α-SMA+) cells (myofibroblasts) were adjacent to, but distinct from, subepithelial PDGFRα+ cells, were always located at the mesenchymal side of subepithelial PDGFRα+ cells, and were distinct from smooth muscle myosin-positive cells. They performed the double labeling of PDGFRα with protein gene product 9.5 (PGP9.5) and α-SMA with PGP9.5. PGP9.5 immunoreactive fibers were found at the mesenchymal surface of subepithelial PDGFRα+ cells, and some fibers were found at the epithelial side of the myofibroblasts. This data show that the promoter driving pdfgra expression is active in subepithelial PDGFRα+ cells but not in subepithelial myofibroblasts. Quantitative polymerase chain reaction (qPCR) was performed on cDNAs obtained frome sorted PDGFRα+ cells and unsorted cells respresenting all cell types dispersed from the mucosa. These data showed that transcripts of pdgfra were significantly enriched in PDGFRα+ cells, and subepithelial PDGFRα+ cells also expressed Toll-like receptors (Tlr4, Tlr5 and Tlr9), purine receptors (P2ry1, P2ry2 and P2ry4), and 5-hydroxytryptamine receptors (Htr4) more strongly compared with the other cell types in mucosa. Htr3a and Htr3b expressions were much lower in PDGFRα+ cells than in other mucosal cells. Other qPCR analysis data revealed that subepithelial PDGFRα+ cells expressed hedgehog signaling molecules (Ptch1 and Gli1) at much greater levels than other cell types. They concluded that PDGFRα is a unique immunolabel for a population of cells that might correspond to the cells identified by electron microscopy as pericryptal fibroblasts. Subepithelial PDGFRα+ cells form a sheath just beneath the epithelium and cover crypts from their base to the luminal surface of epithelium. The roles of these cells in physiological and pathophysiological processes are unknown, but the labeling techniques and the use of a reporter strain that we have characterized will make comprehensive studies of these cells possible for the first time. Several key transcripts are expressed by these cells in mouse, suggesting these cells may have modulatory functions in immune and sensory responses and in the maintenance of mucosal homeostasis.

A Simple Alkaline Method for Decellularizing Human Amniotic Membrane for Cell Culture

Human amniotic membrane is a standard substratum used to culture limbal epithelial stem cells for transplantation to patients with limbal stem cell deficiency. Various methods were developed to decellularize amniotic membrane, because denuded membrane is poorly immunogenic and better supports repopulation by dissociated limbal epithelial cells. Amniotic membrane denuding usually involves treatment with EDTA and/or proteolytic enzymes; in many cases additional mechanical scraping is required. Although ensuring limbal cell proliferation, these methods are not standardized, require relatively long treatment times and can result in membrane damage. We propose to use 0.5 M NaOH to reliably remove amniotic cells from the membrane. This method was used before to lyse cells for DNA isolation and radioactivity counting. Gently rubbing a cotton swab soaked in NaOH over the epithelial side of amniotic membrane leads to nearly complete and easy removal of adherent cells in less than a minute. The denuded membrane is subsequently washed in a neutral buffer. Cell removal was more thorough and uniform than with EDTA, or EDTA plus mechanical scraping with an electric toothbrush, or n-heptanol plus EDTA treatment. NaOH-denuded amniotic membrane did not show any perforations compared with mechanical or thermolysin denuding, and showed excellent preservation of immunoreactivity for major basement membrane components including laminin α2, γ1-γ3 chains, α1/α2 and α6 type IV collagen chains, fibronectin, nidogen-2, and perlecan. Sodium hydroxide treatment was efficient with fresh or cryopreserved (10% dimethyl sulfoxide or 50% glycerol) amniotic membrane. The latter method is a common way of membrane storage for subsequent grafting in the European Union. NaOH-denuded amniotic membrane supported growth of human limbal epithelial cells, immortalized corneal epithelial cells, and induced pluripotent stem cells. This simple, fast and reliable method can be used to standardize decellularized amniotic membrane preparations for expansion of limbal stem cells in vitro before transplantation to patients.

Membranous nephropathy secondary to Graves' disease with deposits of thyroid peroxidase in an adult.

A 40-year-old woman was diagnosed with Graves' disease in 2001 and treated with thiamazole, but disease control was poor. She was referred to our hospital in 2011 for exacerbation of proteinuria, which had been present since 2006. Urinalysis showed a protein/creatinine ratio of 4.2g/gCre and microhematuria, and a renal biopsy was performed. On electron microscopy, high electron density deposits were seen on the epithelial side of the glomerular basement membrane. IgG was also deposited along the glomerular loop wall, and membranous nephropathy was diagnosed. Immunostaining revealed thyroid peroxidase deposits but not thyroglobulin antigen deposits, suggesting that the membranous nephropathy was secondary to Graves' disease. The membranous nephropathy improved with 131I treatment. To our knowledge, this is the first adult case of membranous nephropathy originating from Graves' disease in which deposits of thyroid peroxidase antigens have been detected.

DALK und perforierende Laserkeratoplastik bei fortgeschrittenem Keratokonus

In cases of contact lens intolerance and/or central corneal scars, corneal transplantation is indicated for advanced keratoconus. This can be performed as deep anterior lamellar keratoplasty (DALK) or as penetrating keratoplasty (PKP). The German keratoplasty registry shows that the proportion of anterior lamellar grafts in Germany has remained stable at approximately 5 % in recent years. Up to now DALK has not been technically standardized but can result in a good visual acuity using the big bubble technique if Descemet's membrane is laid bare intraoperatively. In 10-20 % a conversion to PKP is required if perforation of Descemet's membrane occurs. In cases of advanced keratoconus PKP is still the method of first choice especially after corneal hydrops due to rupture of Descemet's membrane. Non-contact excimer laser trephination seems to be especially beneficial for eyes with iatrogenic keratectasia after LASIK and those with repeat grafts in cases of keratoconus recurrence due to the graft being too small. For donor trephination from the epithelial side, an artificial chamber is used. Wound closure is achieved by a double running cross-stitch suture according to Hoffmann. Graft size is adapted individually depending on corneal size (as large as possible and as small as necessary). Limbal centration is given priority intraoperatively due to optical displacement of the pupil. Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient centration, reduces vertical tilt and horizontal torsion of the graft in the recipient bed, thus resulting in significantly less all-sutures-out keratometric astigmatism (2.8D versus 5.7D), higher regularity of the topography (SRI 0.80 vs. 0.98) and better visual acuity (0.80 vs. 0.63) in contrast to the motor trephine. The stage of the disease does not influence functional outcome after excimer laser PKP. In cases with optimal course DALK achieves the same visual outcome as mechanical PKP but the healthy endothelium can be preserved and endothelial immune reactions are prevented in keratoconus. In contrast to the undisputed clinical advantages of excimer laser keratoplasty with orientation teeth/notches in keratoconus, the major disadvantage of femtosecond laser application is still the necessity of suction and applanation of the cone during trephination.

Knockdown of the Hypertension-Associated Gene NOSTRIN Alters Glomerular Barrier Function in Zebrafish ( Danio rerio )

Hypertension is one of the major risk factors for chronic kidney disease. Using quantitative trait loci analysis, we identified the gene of the F-BAR protein NOSTRIN in the center of an overlapping region in rat and human quantitative trait loci that are associated with hypertension. Immunohistochemical analysis revealed a predominantly podocytic expression pattern of NOSTRIN in human and mouse glomeruli. Further, NOSTRIN colocalizes with cell-cell contact-associated proteins β-catenin and zonula occludens-1 and interacts with the slit-membrane-associated adaptor protein CD2AP. In zebrafish larvae, knockdown of nostrin alters the glomerular filtration barrier function, inducing proteinuria and leading to ultrastructural morphological changes on the endothelial and epithelial side and of the glomerular basement membrane of the glomerular capillary loop. We conclude that NOSTRIN expression is an important factor for the integrity of the glomerular filtration barrier. Disease-related alteration of NOSTRIN expression may not only affect the vascular endothelium and, therefore, contribute to endothelial cell dysfunction but might also contribute to the development of podocyte disease and proteinuria.

Opposing effect of amniotic membrane on angiogenesis originating from amniotic epithelial cells

There are controversies about the effects of amniotic membrane (AM) on angiogenesis. It was recently hypothesised that denuded AM (without epithelial cells) can induce angiogenesis. The results from the dorsal skinfold chamber method in an animal model and aortic ring assay showed that the epithelial side of the AM inhibits vessel sprouting and reduces capillary numbers, while the mesenchymal side of the AM increases angiogenesis. These data answered the controversies about the angiogenic capability of the AM and raised some questions about the mechanisms by which the AM affects angiogenesis. In this article, mechanism(s) by which the AM affects angiogenesis and viability state of amniotic cells and its effect on angiogenesis have been propounded.

Endothelial graft precutting from the epithelial and endothelial side with the femtosecond laser, on cornea stored in a new corneal bioreactor

AbstractPurpose To compare femtosecond laser endothelial graft precut from epithelial and endothelial side, on corneas stored in a new corneal bioreactorMethods Human corneas unsuitable for transplantation for serological reasons and procured by the Auvergne‐Loire eye bank (Saint Etienne, France) were used after informed consent of the relatives, as authorized by French bioethics laws. Femtosecond laser lamellar cuts were realized on corneas stored in a new corneal bioreactor, patented by our laboratory, designed to maintain a constant endothelial pressure and to permit an epithelial aplanation without opening the device. Lamellar cuts of several thickness were realized with corneal epithelium or corneal endothelium side up, but always with epithelial aplanation. OCT images (Casia SS1000, Tome) were realized in the bioreactor before and after each cut. Endothelial viability was determined by using a triple Hoechst/Ethidium/Calcein labeling (HEC, IOVS Pipparelli 2011) coupled with image analysis of the whole endothelial surface immediately after the cut. Surface roughness was assessed by scanning electron microscopyResults This study demonstrates the possibility to realise femtoseconde laser endothelial graft precut directly in a dedicated storage device. First results of endothelial viability in function of lamellar graft thickness and lamellar cut side will be presented as well as surface roughnessConclusion Capacity to realize femtosecond laser endothelial graft precut directly in a storage device could improve the quality and security of delivered lamellar grafts

The Bi-Functional Organization of Human Basement Membranes

The current basement membrane (BM) model proposes a single-layered extracellular matrix (ECM) sheet that is predominantly composed of laminins, collagen IVs and proteoglycans. The present data show that BM proteins and their domains are asymmetrically organized providing human BMs with side-specific properties: A) isolated human BMs roll up in a side-specific pattern, with the epithelial side facing outward and the stromal side inward. The rolling is independent of the curvature of the tissue from which the BMs were isolated. B) The epithelial side of BMs is twice as stiff as the stromal side, and C) epithelial cells adhere to the epithelial side of BMs only. Side-selective cell adhesion was also confirmed for BMs from mice and from chick embryos. We propose that the bi-functional organization of BMs is an inherent property of BMs and helps build the basic tissue architecture of metazoans with alternating epithelial and connective tissue layers.

Aspectos clínicos do enxerto conjuntival 360º e do implante da membrana amniótica criopreservada no tratamento de úlceras de córnea em cães

To evaluate the clinical application of implant of the canine cryopreserved amniotic membrane (DMEM plus DMSO 1:1) and 360° conjunctival flap in the treatment of progressive corneal ulceration. 10 dogs of the different breeds, males and females, aging four months to four years old with deep corneal ulceration and different clinical progression were divided in two groups: G1=360° conjunctival graft (n=5) and G2=implant of amniotic membrane, sutured at the edge of the ulcer with epithelial side facing up, associated with the third eyelid flap (n=5). The comparative analysis between groups was: complications, blepharospasm, ocular secretion, corneal vascularization, epithelial defect and corneal opacification in six moments (first emergency care, surgery and 3, 7, 15 and 30 days of postoperative). Without epithelial defect was evaluated quality of the scar. It was used score scale for subjective to qualify of the ocular signs. In G1, it was observed the non-adherence of the conjunctival graft to the ulcer (n=2), dehiscence of the suture (n=2), anterior synechia (n=2) and intense chemosis (n=1). In G2, it was not observed these complications. It was not significant difference between the groups to others ocular parameters, but it was different among the start and end moments of the same groups (ocular secretion, corneal vascularization, epithelial defect). The corneal opacity was more intense in G1. According to the clinical results, the cryopreserved amniotic membrane implant proved to be as effective in the corneal ulceration in comparison to the 360° conjunctival flap, because probably, the membrane promoted a trophic support for epithelialization, anti-inflamatory effect associated with important to the end result phenotype.

Side dependent effects of the human amnion on angiogenesis

IntroductionAmnion (AM), the innermost layer of human placenta, has a variety of functions such as capability to reduce scarring and inflammation, as well as anti-microbial and immunoregulatory properties. However, there are challenging reports about angiogenic and anti-angiogenic effects of the AM. The aim of this study was to evaluate whether the angiogenesis is dependent on epithelial or mesenchymal sides of this membrane. MethodsDorsal skinfold chamber model was performed on male rats. A layer of dorsal skin of rats was removed and the AM was implanted in either epithelial side up or mesenchymal side up position. Intra-vital microscopy was done one week after tissue transplantation. In vitro evaluation of angiogenesis was also performed using rat aortic ring assay on the AM. ResultsThe number of vessel sprouts and their lengths were increased more significantly in epithelial side up group comparing to the control group. Inhibitory effect of epithelial side of the AM on angiogenesis was clearly seen in mesenchymal side up group. Both number and length of sprouts in mesenchymal up group were decreased in comparison to epithelial side up group. In aortic ring assay, angiogenesis was detected on the AM after removal of the amniotic epithelial cells. Discussion & conclusionThis study showed that the AM has both angiogenic and anti-angiogenic properties, which is surface dependent. Therefore, the AM can have a vast application in both ischemic organs through inducing angiogenesis and pathological situations such as cancer in which angiogenesis must be inhibited.

Secondary correction of posttraumatic orbital wall adhesions by membranes laminated with amniotic membrane

The objective of the study was to find out if human amniotic membrane could be used for corrective surgery after trauma to the orbital wall. Because of its proposed antiadhesive qualities, it seemed to be potentially suitable. We studied 8 men (mean age 37 (range 19–74) years) who had deficient ocular movement after fractures of the orbital floor. Five of them had already been operated on. Inclusion criteria were trauma dating back more than 4 months and a soft tissue stricture in the orbital floor diagnosed by magnetic resonance imaging. Patients were treated secondarily with lysis of adhesions and insertion of allogeneic human amniotic membrane laminated on to polyglactin 910/polydioxanone foil, which functioned as the carrier material. Patients were followed up for 3 months, by which time disorders of motility of the ocular bulb had disappeared completely in 5. Two patients had improved motility and a reduction in both their subjective and objective symptoms. One patient had no improvement. The considerable reduction in adhesions and scarring after insertion of the membrane confirms previous assumptions, according to which the epithelial side of the human amniotic membrane has an antiadhesive effect because of its smooth surface.

Abstract 516: Knockdown of the Hypertension Associated Gene NOSTRIN Alters Glomerular Barrier Function in Zebrafish (Danio rerio)

The bioavailability of nitric oxide (NO) has been associated with the development and progression of vascular and renal disease. NOSTRIN (for eNOS Traffic Inducer) has primarily been recognized as one important regulator of eNOS, the prime source of NO in the cardiovascular system, with a possible role in the pathogenesis of pre-eclampsia and the development of increased intrahepatic resistance in liver disease. Here, we identified NOSTRIN in the center of a QTL-overlap region in rat and human trait loci that are associated with hypertension. Glomerular NOSTRIN expression is detectable in podocytes in human and rat glomeruli and podocytic NOSTRIN expression is diminished in hypertensive kidney disease. We show that knockdown of NOSTRIN alters the glomerular filtration barrier function in larval zebrafish, inducing proteinuria and leading to ultrastructural morphological changes on the endothelial as well as epithelial side and the GBM of the glomerular capillary loop. We also demonstrate that NOSTRIN interacts with proteins associated with the podocyte slit membrane. We conclude that NOSTRIN expression is an important factor for the integrity of the glomerular filtration barrier. Disease related alteration of NOSTRIN expression may not only affect the vascular endothelium and therefore contribute to endothelial cell dysfunction but may also contribute to the development of podocyte disease and proteinuria.

Clinical transplantation ofex vivoexpanded autologous limbal epithelial cells using a culture medium with human serum as single supplement: a retrospective case series

Presently, our clinic is the only centre in Scandinavia that offers patients with corneal surface pathology including limbal stem cell deficiency (LSCD) transplantation of ex vivo expanded limbal epithelial cells (LECs). We here present clinical data of the first nine patients with LSCD who were transplanted with autologous LECs expanded in medium completely free of any animal-derived products and non-human/recombinant growth factors (including Cholera Toxin), and with autologous human serum as the only growth supplement. We conducted a noncomparative retrospective study of patients with LSCD at our centre between 2009 and 2011. The diagnosis was based on history and clinical signs. A biopsy was taken from healthy limbus, and the epithelium was expanded on amniotic membrane (AM) in medium containing autologous serum and subsequently transplanted to the affected eye. Successful outcome was defined as relief of pain and photophobia and/or improved best corrected visual acuity (BCVA) and/or reestablishment of a stable corneal epithelium and regression of corneal vascularization. Five of the nine transplanted patients (55.6%) had an improvement in either subjective symptoms or objective findings (11- to 28-month follow-up). Our clinical study shows that patients with LSCD can be treated successfully with transplantation of LECs expanded ex vivo in a medium with autologous serum as the only growth supplement. The use of this novel culture system, which is devoid of animal-derived products and non-human/recombinant growth factors (including Cholera Toxin), reduces the risks of inter-species disease transmission and host immune responses to xenogenic proteins, both obvious advantages for the patient.

Ocular Surface Reconstruction with Cultivated Limbal Epithelial Cells in Limbal Stem Cell Deficiency: One-year Follow-up Results

To evaluate the 1-year follow-up results of cultivated limbal epithelial cell (CLEC) transplantation in unilateral limbal stem cell deficiency (LSCD). One-year follow-up results of five unilateral LSCD patients who had undergone CLEC transplantation were evaluated. Parameters for this evaluation were: fluorescein staining of ocular surface, corneal vascularization and status of epithelium with slit lamp, and visual acuity. 1.5-mm limbal biopsy was performed from the superior limbus of the healthy eyes, broke into two equal pieces, expanded on human amniotic membrane (hAM) and inserts for 14 days until getting 20 mm in size. CLECs on hAMs were used directly, and cells on inserts were used after detachment procedure. The symblepharon and pannus tissues were removed, superficial keratectomy was performed. CLEC on hAMs were transplanted with the epithelial side up onto the bare corneal stroma, sutured to the conjunctiva with 10-0 nylon sutures. Free CLEC layer from insert was placed on hAM as a second layer, additional hAM was used as a protective layer all over other tissues. Median age was 44.4 years (14-71). The etiology was chemical burn in all patients. Median duration of symptoms was 10 years (2-18), median follow-up period was 12.6 (12-12.5) months. Preoperative best corrected visual acuities (BCVA) were light perception in three patients, counting fingers at 50 cm in one patient and 3/10 in one patient. Visions were improved in all patients. Postoperative BCVA 12 months after the surgery were between counting fingers at 3 meters to 6/10. There was a temporary hemorrhage between the two layers of hAMs in one patient at the early postoperative period. Peripheral corneal vascularization has occurred in three patients, in patient corneal vascularization has reached to the paracentral area. CLEC transplantation is an efficient treatment option for unilateral LSCD in mid-long term.

Inverse Cutting of Posterior Lamellar Corneal Grafts by a Femtosecond Laser

Purpose Posterior lamellar grafting of the cornea has become the preferred technique for treatment of corneal endothelial dysfunction. Posterior lamellar grafts are usually cut by a micro-keratome or a femto-second laser after the epithelial side of the donor cornea has been applanated. This approach often results in variable central graft thickness in different grafts and an increase in graft thickness towards the periphery in every graft. The purpose of this study was to evaluate if posterior lamellar grafts can be prepared from the endothelial side by a femto-second laser, resulting in reproducible, thin grafts of even thickness.Methods A CZM 500 kHz Visumax femto-second laser was used. Organ cultured donor grafts were mounted in an artifical anterior chamber with the endothelial side up and out. Posterior grafts of 7.8 mm diameter and 130 micron thickness were prepared by femto-second laser cutting. A standard DSAEK procedure was performed in 10 patients with Fuchs endothelial dystrophy. Patients were followed-up regularly and evaluated by measurement of complications, visual acuity, corneal thickness (Pentacam HR), and endothelial cell density.Results Femto-laser cutting of grafts and surgery was uncomplicated. Rebubbling was necessary in 5 of 10 cases (normally only in 1 of 20 cases). All grafts were attached and cleared up during the first few weeks. After six months, the average visual acuity was 0.30 (range: 0.16 to 0.50), corneal thickness was 0.58 mm (range 0.51 to 0.63), and endothelial cell density was 1.570 per sq. mm (range: 1.400 to 2.000 cells per sq. mm). The grafts were of uniform thickness, but substantial interface haze was present in most grafts.Conclusions Posterior lamellar corneal grafts can be prepared from the endothelial side using a femto-second laser. All grafts were clear after 6 months with satisfying endothelial cell counts. Poor visual acuity caused by interface scatter was observed in most patients. Femto-second laser cutting parameters needs to be optimised to enable smooth cutting in the posterior stroma.

Dural Repair After Craniotomy and the Use of Dural Substitutes and Dural Sealants

A dura mater substitute in decompressive craniectomies must protect the brain while providing a dissection plane between the cortex and myocutaneous layer. The human amniotic membrane (AM) has anti-inflammatory, wound healing, and differentiation properties. We tested AM properties as a dural substitute by comparing the outcomes to biological ones.We prospectively collected data on 25 patients who randomly underwent decompressive craniectomy with lyophilized AM patches and 25 in which biological substitutes were utilized between 2015 and 2019. The AM was laid with the epithelial side facing the brain because of the anti-adhesive proprieties, while the chorion facing the myocutaneous flap. We collected data on demographics, neurological status, comorbidities, and surgical outcomes. Additionally, we created a score – dura mimicking score– and reviewed postoperative imaging and pathological specimens.The majority (96%) of AM grafts were integrated into native dura. Thirteen patients scored as excellent and 11 good on our “dura mimicking score”, showing tissue integration ability but no cerebral cortex adhesion. The histopathological analysis showed that AM had thick plates of dense fibrous tissue with small reactive vessels, reactive fibroblasts, and lymphocytes infiltrate. The AM group's first outcomes were not different from the biological substitute patients but higher integration rate to the dura and less adhesion to the myocutaneous flap in AM patients.We documented the anti-adhesive, protective, and integrative properties of AM dural substitute patches in patients who underwent decompressive craniectomies, comparing the intraoperative differences and postoperative outcomes to biological dural substitutes.

Perspektiven der Excimerlaser-Trepanation für die Keratoplastik

The purpose of this paper is to demonstrate the evolution of laser keratoplasty and to outline the potential future perspectives of this technique. For non-contact donor trephination from the epithelial side an artificial anterior chamber has been used. Since 1989 more than 3,300 penetrating keratoplasty operations (PKP) have been performed successfully with the Zeiss-Meditec MEL60® excimer laser in Erlangen and Homburg/Saar. Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient decentration, reduces vertical tilt and horizontal torsion of the graft in the recipient bed, thus resulting in significantly less all-sutures-out keratometric astigmatism, higher regularity of the topography and better visual acuity. Besides less blood-aqueous barrier breakdown during the early postoperative course after PKP, excimer laser trephination does not induce cataract formation and does not impair the graft endothelium. Likewise, the rate of immunological graft rejections is not adversely affected by the excimer laser. In addition, trephination of an instable cornea is facilitated. Because of undisputed clinical advantages, especially in eyes with keratoconus, excimer laser trephination with orientation teeth/notches is still favored in Homburg/Saar in daily practice. The femtosecond laser (FSL)-assisted keratoplasty technique is very exciting but a prospective randomized study is required to determine potential benefits over excimer laser PKP.

Wound Architecture of Clear Corneal Incision With or Without Stromal Hydration Observed With 3-Dimensional Optical Coherence Tomography

To evaluate wound architectures of a clear corneal incision and the duration of stromal edema caused by intentional hydration in cataract surgery using 3-dimensional (3-D) cornea and anterior segment optical coherence tomography (OCT). Prospective, randomized study. On 30 eyes of 23 patients, cataract surgery was performed through a clear corneal incision created with a 2.4-mm blade. After confirming the water tightness of the clear corneal incision at the end of surgery, 15 randomly selected eyes received stromal hydration, and the remaining 15 eyes did not. Using the 3-D cornea and anterior segment optical coherence tomography, wound architecture was assessed 1 day, 1 week, and 2 weeks after surgery. There was a statistically significant difference in corneal thickness at the clear corneal incision between eyes with and without stromal hydration 1 day and 1 week after surgery (P < .001 and P < .05, Mann-Whitney U test), but not at 2 weeks after surgery. On day 1, gaping at the epithelial side was seen in 6.7% (2 eyes), gaping at the endothelial side in 30% (9 eyes), misalignment of the roof and floor of incision in 40% (12 eyes), and local detachment of Descemet membrane in 36.7% (11 eyes). These imperfections improved with time. Using the 3-D cornea and anterior segment optical coherence tomography, detailed architectures of the clear corneal incision were investigated. It was found that the effect of stromal hydration lasted for at least 1 week after surgery.