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The purpose of this study was to analyze the influence of patient positioning on intraocular pressure (IOP) after Descemet membrane endothelial keratoplasty (DMEK) in pseudophakic patients treated for Fuchs endothelial corneal dystrophy.Forty patients were included in this prospective, single-blinded, randomized controlled clinical trial. Patients received a YAG iridotomy 1 day before surgery and an 80% anterior chamber tamponade [20% concentration of sulfur hexafluoride (SF6)]. Postoperative positioning was either supine (group 1) or seated (group 2, at least 30 degrees upper-body high position). IOP was measured with iCare.There was no statistically significant difference in IOP postoperatively [group 1 vs. group 2-after 1h: 13.9 mm Hg (±4.2 mm Hg) versus 13.6 mm Hg (±4.1 mm Hg) (P = 1.00); after 2h: 13.9 mm Hg (±5.4 mm Hg) versus 15.3 mm Hg (±4.6 mm Hg) (P = 0.370); after 4h: 13.8 mm Hg (±4.2 mm Hg) versus 15.2 mm Hg (±4.2 mm Hg) (P = 0.401]. In group 1, 10% of patients showed IOP decompensations well above 30 mm Hg, and in group 2, there were no IOP decompensations. Seated position led to relative risk reduction of 100% and absolute risk reduction of 10% regarding IOP decompensations. The number of patients needed to position seated to prevent 1 additional IOP decompensation was 10. Rebubbling rates, best spectacle-corrected visual acuity, and reduction of corneal thickness were comparable between the 2 groups in the follow-up period up to 1 month.After DMEK in pseudophakic eyes with 80% anterior chamber tamponade, positioning patients with at least 30 degrees elevation of the upper body up immediately after surgery until bedtime prevents IOP decompensations.

More than ever research into changes in the eye caused by long-term space flight is becoming the focus of the international and national space agencies National Aeronautics and Space Administration (NASA), European Space Agency (ESA) and German Aerospace Center (DLR). In addition to space radiation-induced cataract formation considerable eye changes, summarized under space flight-associated neuro-ocular syndrome (SANS), can occur.This article gives an overview of the current state of research and future directions in the field of research concerned with ocular alterations in SANS and presents the relevance for terrestrial ophthalmological research.An analysis of existing publications on SANS in PubMed and reports on the risk of SANS published by the NASA of the USA was carried out.The reasons for the development of the eye changes in space have not been clarified. Factors such as the increase in intracranial pressure, fluid shifts, hypercapnia and genetic factors are the subject of intensive research efforts. A terrestrial model for the induction of papilledema could be established (bed rest studies with -6° head-down tilt as a space analogue). Countermeasures for the development of eye changes, such as intermittent artificial gravity, are the subject of current research studies.Research into SANS as part of bed rest studies will provide further important insights in the future for space research and also for terrestrial research. Clinical research projects can be derived from space research.HINTERGRUND: Mehr denn je rückt die Erforschung der Veränderungen am Auge, die durch den Aufenthalt im All verursacht werden, ins Zentrum des Interesses der internationalen und nationalen Weltraumagenturen NASA (National Aeronautics and Space Administration), ESA (European Space Agency) und DLR (Deutsches Zentrum für Luft- und Raumfahrt). Neben weltraumstrahlungbedingten Katarakten können erhebliche Augenveränderungen, zusammengefasst unter dem „space flight-associated neuro-ocular syndrome“ (SANS) auftreten.Diese Übersicht soll den aktuellen Forschungsstand und künftige Bestrebungen auf dem Gebiet der Erforschung der Augenveränderungen bei SANS wiedergeben und die Relevanz für die terrestrische ophthalmologische Forschung aufzeigen.Es erfolgt eine Analyse der bestehenden Publikationen zu dem Thema in PubMed sowie von Berichten bezüglich des Risikos von SANS, veröffentlicht von der NASA der USA.Die Ursachen für die Entstehung der Augenveränderungen im All sind nicht geklärt. Faktoren wie die Erhöhung des intrakraniellen Drucks, Flüssigkeitsverschiebungen, Hyperkapnie und genetische Einflüsse sind Gegenstand intensiver Forschungsbemühungen. Ein terrestrisches Modell zur Induktion des Papillenödems konnte etabliert werden (Bettruhestudien mit −6° Kopftieflagerung als Weltraumanalogon). Gegenmaßnahmen zur Entwicklung der Augenveränderungen, wie beispielsweise intermittierend künstliche Schwerkraft, sind Gegenstand der aktuellen Studien.Die Erforschung von SANS im Rahmen von Bettruhestudien wird in Zukunft sowohl für die Weltraumforschung als auch für die terrestrische Forschung weitere wichtige Erkenntnisse liefern. Klinische Forschungsprojekte können aus der Weltraumforschung abgeleitet werden.

Purpose Deep anterior lamellar keratoplasty (DALK) has become a safe and standardized technique for the treatment of corneal diseases. The use of femtosecond lasers for corneal trephination in DALK allows for a precise and controlled corneal trephination very close to Descemet’s membrane (DM) which is important for a successful pneumatic dissection and results in separation of Pre-Descemet’s layer (Dua’s layer, PDL) and/or DM from the stroma. However, even with newer curved contact interfaces the cornea becomes massively warped during trephination causing irregular trephination patterns which results in high postoperative astigmatism. Here we present a novel technique of Femto-DALK using a non-contact liquid interface where the cornea keeps its natural curvature during the complete laser process. Methods Case series of two patients, which underwent femtosecondlaser-assistant deep anterior lamellar keratoplasty by using a non-contact liquid interface. The laser device (Ziemer LDV Z8, Ziemer Ophthalmic Systems AG, Port, Switzerland) was used for trephination of the donor and recipient cornea. In one patient Femto-DALK was combined with femtolaser-assisted cataract surgery (Femto-Phaco). Read-out parameters were the feasibility of the technique and postoperative outcome. Results Trephination was successful in both cases leading to a circular trephination very close to the recipients’ Descemet’s membrane. In both patients a big bubble type 1 was induced successfully. Conclusions Femtosecondlaser-assisted DALK using a liquid interface is a novel procedure representing an alternative to manual DALK or Femto-DALK with a contact interface. Future studies need to evaluate outcomes and complication rates in comparison to manual DALK and microscope-integrated Optical Coherence Tomography-aided DALK.

The study aims to compare outcomes after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in keratoconic eyes with or without previous hydrops.Retrospective analysis of 211 eyes who received PK (group 1, n = 74 [history of hydrops: n = 33]) or DALK (group 2, n = 137 [history of hydrops: n = 9]) from 2012 to 2019 at the Department of Ophthalmology, University of Cologne, Germany. Analysis included best spectacle-corrected visual acuity (BSCVA), complications, immune reactions, graft survival and keratometry, and subgroup analyses for subjects with or without previous hydrops.Follow-up was 34.0 ± 23.6 months in group 1 and 30.7 ± 22.5 months in group 2. No significant difference was found in the course of BSCVA between groups 1 and 2 (p = 0.182) and in postoperative BSCVA between eyes with and without previous hydrops, regardless of the surgical method (p = 0.768). Endothelial immune reactions occurred exclusively in group 1 and did not occur more frequently in eyes with previous hydrops (p = 0.377). A higher risk of complications for eyes with previous hydrops was observed (p = 0.022). There was no difference in astigmatism and maximum keratometry (KThe prognosis for visual outcome after keratoplasty including visual acuity, astigmatism, and K

Die vorliegende Arbeit gibt einen Überblick über die aktuellen therapeutischen Optionen des Keratokonus. Diese unterlagen in den letzten Jahren einem großen Wandel, einige neue therapeutische Möglichkeiten sind ergänzend hinzugekommen. Die Visusverbesserung durch Kontaktlinsen und Hornhauttransplantation wird mittlerweile durch die Anwendung von intracornealen Ringsegmenten ergänzt. Das Crosslinkingverfahren zum Stopp der Progression der Erkrankung wurde mittlerweile auch durch den Gemeinsamen Bundesausschuss im letzten Jahr positiv bewertet. Auch hier gibt es neue Trends, die das Verfahren in Zukunft beschleunigen und schmerzfrei machen könnten. Sehr neu sind die Therapiemöglichkeiten der mini-DMEK und der prädescemetalen Hornhautnähte beim akuten Keratokonus, für den bisher keine effektive operative Therapie zur Verfügung stand. Diese Übersicht gibt einen Einblick in die aktuellen Entwicklungen in Kombination mit modernster intraoperativer Bildgebung zur Therapie des Keratokonus.

Purpose To compare two surgical treatment options for acute corneal hydrops in keratoconus: Mini-DMEK versus predescemetal sutures. Methods Sixteen patients were treated by either Mini-Descemet membrane endothelial keratoplasty (Mini-DMEK) (n = 7, group 1) or predescemetal sutures (n = 9, group 2) early after onset of acute hydrops. Visual acuity, maximum corneal thickness (SD-OCT) in the affected oedematous area, complications and recurrence rates were retrospectively compared between both groups. Measurements were taken immediately preoperatively as well as 1 day, 1 week and 1 month postoperatively (Table 1). Results Both groups showed reductions in corneal thickness and increased visual acuity shortly after surgery. In group 1 (average age 33 years ± 7 years), the best corrected visual acuity (BCVA) increased from logMAR 1.65 ± 0.7 before Mini-DMEK to logMAR 0.93 ± 0.6 30 days after Mini-DMEK (p = 0.046). During that period, maximum corneal thickness decreased from 1159 ± 338 µm before surgery to 531 ± 75 µm after Mini-DMEK (p = 0.046). Patients from group 2 (average age 34 ± 10 years) had a BCVA of logMAR 1.59 ± 0.8 which increased to logMAR 0.97 ± 0.5 (p = 0.014) 30 days after surgery. At the same time, the preoperative maximum corneal thickness decreased from 1439 ± 272 µm to 476 ± 162 µm (p = 0.014). There was no difference in corneal thickness or BCVA one month after the surgical intervention between both groups (p = 0.394 and p = 0.871). Conclusions Both techniques, Mini-DMEK and predescemetal sutures, are effective in the treatment of an acute hydrops in keratoconus. Mini-DMEK appears to be beneficial in large DM tears.

Background/AimsTo analyse graft detachments prior to rebubbling, the influence of rebubbling on the postoperative outcome after Descemet membrane endothelial keratoplasty (DMEK) and the need for rebubbling on the contralateral eye.MethodsIn this retrospective cohort study, out of 1541 DMEKs, optical coherence tomography scans and clinical records of 499 eyes undergoing rebubbling after DMEK at the University Hospital of Cologne, Cologne, Germany, were examined. Main Outcome measures were (a) number, localisation and size of graft detachments; (b) influence of rebubbling/s on postoperative outcome after 12 months; and (c) rebubbling risk of the contralateral eye after DMEK.ResultsMean number of detachment areas was 2.02±0.9. Mean lateral diameter of all detachments was 4534.76±1920.83 μm. Mean axial diameter was 382.53±282.02 μm. Detachments were equally distributed over all regions of the cornea. Best spectacle corrected visual acuity ( BSCVA) after 12 months was 0.197±0.23 logarithm of the minimum angle of resolution, endothelial cell density (ECD) was 1575.21±397.71 cells/mm2 and mean central corneal thickness (CCT) was 566.37±68.11 μm. BSCVA, CCT, ECD or endothelial cell loss of all rebubbled patients were not influenced by the number of rebubblings or the time between DMEK and rebubbling. Of the rebubbled patients, which received a DMEK subsequently on the other eye, 193 (58.8%) also received a rebubbling, which was significantly higher, when compared to the overall rebubbling rate of 32.3% (p=0.000).ConclusionsThe overall number of rebubblings has no influence on the postoperative outcome after DMEK, if a rebubbling becomes necessary. Patients who received a rebubbling on one eye have an elevated risk for a rebubbling on the fellow eye.

PURPOSE Descemet membrane endothelial keratoplasty (DMEK) has developed into a safe procedure for the replacement of diseased corneal endothelium. However, DMEK still results in a significant donor endothelial cell loss. Here, we compare 2 different graft implantation techniques. METHODS Twenty patients undergoing DMEK, where a DMEK injection cartridge was used to flush the graft into the anterior chamber (G-38635 single-use DMEK-Cartridge; Geuder AG, Heidelberg, Germany; group A), were retrospectively compared with 20 patients, where a standard lens injection cartridge (AT.Smart Cartridge; Carl Zeiss Meditec AG, Jena, Germany; group B) was used to push the graft with a plunger. Outcome parameters were intraoperative orientation of the graft, insertion-to-attachment time, rebubbling rates, and postoperative best spectacle-corrected visual acuity, endothelial cell count, and central corneal thickness after 12 months. The surfaces of both cartridges were evaluated by scanning electron microscopy. RESULTS In group A, the insertion-to-attachment time was significantly higher (P = 0.003). Initially, the graft was oriented correctly in 40% of the patients in group A compared with 90% in group B (P = 0.001). No differences were obtained between both groups regarding central corneal thickness, endothelial cell count or best spectacle-corrected visual acuity, and rebubbling rates after 12 months. Scanning electron microscopy analysis demonstrated a rougher and sharper surface of the shooter of group B. CONCLUSIONS This study shows significant differences between both insertion techniques regarding correct graft orientation directly after graft implantation leading to prolonged insertion-to-attachment time when the graft is flushed instead of pushed into the anterior chamber.

Purpose To describe a new surgical option for the treatment of acute corneal hydrops in keratoconus and to present the first results. Methods This is a retrospective analysis of 3 patients who presented to our clinic with a massive corneal hydrops in acute keratoconus and were treated by mini-Descemet membrane endothelial keratoplasty (DMEK). According to the size and the shape of the gap in the patient's Descemet membrane (DM), 1 DMEK graft was trephined with a round 5-mm punch. The other grafts were trimmed with a razor blade to a width of about 3 mm and a length adjusted to the length of the defect of the recipients' DM. The graft was inserted with a regular intraocular lens shooter. Correct unfolding of the graft was controlled by using intraoperative optical coherence tomography. At the end of the surgery, the graft was attached to the posterior corneal surface by a small air bubble. Thereafter, the complete anterior chamber was filled with 20% SF6 gas. Results All 3 patients (age 32 ± 3 years on average) showed a rapid increase in uncorrected visual acuity from the logarithm of the minimum angle of resolution (LogMAR) 1.66 (±0.46) before mini-DMEK to the LogMAR 1.2 (±0.3) within 6 to 8 weeks after mini-DMEK. The thickest corneal point within the edematous cornea decreased in all 3 patients (1088 ± 280 μm before surgery vs. 630 ± 38 μm 1 week after surgery). One mini-DMEK failed in a first attempt. In this patient, the recipient DM was under strong tension and showed a pronounced dehiscence. Therefore, a small part of the recipient's DM around the preexisting gap in DM was removed before a second mini-DMEK graft was placed successfully. The other 2 patients developed partial graft detachment within 1 to 2 weeks after surgery. However, the corneas of these patients were dehydrated to physiological levels after mini-DMEK, and despite partial detachment, there was no relapse of the hydrops. Conclusions Mini-DMEK could be helpful in patients with larger defects and detachments of DM in very ectatic corneas in the acute phase of corneal hydrops in acute keratoconus. These patients may not be successfully treated by intracameral gas application alone or in combination with pre-Descemetal sutures. Further investigations are needed to identify factors helping to decide on the best surgical approach in hydrops in acute keratoconus.

The treatment of acute corneal hydrops due to keratoconus has so far been limited to awaiting the spontaneous resorption of corneal edema, supportive care, and finally keratoplasty. A recent publication describes the surgical reattachment of Descemet Membrane (DM) facilitated by pre-Descemetic sutures and anterior chamber air/gas filling. Here, we present a novel microscope-integrated intraoperative optical coherence tomography (MI-OCT)-guided technique for the immediate reattachment of DM in corneal hydrops due to keratoconus in 2 male patients with small central DM defects.Case series of 2 consecutive patients with acute corneal hydrops due to keratoconus. The novel technique consists of the MI-OCT-guided puncture and drainage of intrastromal fluid pockets combined with anterior chamber sulfur hexafluoride-fill and pre-descemetic sutures using a commercially available MI-OCT (iOCT; Haag Streit Surgical, Wedel, Germany).After uneventful surgery, corneal edema showed fast resolution and DM was reattached to the corneal stroma. In both patient's central corneal thickness decreased after surgery and visual acuity improved.MI-OCT guided micropuncture of stromal edema combined with compression sutures and SF6 tamponade is a new therapeutic option in acute corneal hydrops with small Descemet membrane defects.

Background After tracheostomy, the airway lacks an essential mechanism for warming and humidifying the inspired air with the consequent functional impairment and discomfort. The purpose of this study was to compare airway hydration with cold-air nebulization versus heated high-flow humidification on medical interventions and tracheal ciliary beat frequency (CBF). Methods Newly tracheostomized patients (n = 20) were treated either with cold-air nebulization or heated humidification. The number of required tracheal suctioning procedures to clean the trachea and tracheal CBF were assessed. Results The number of required suctions per day was significantly lower in the heated humidification group with medians 3 versus 5 times per day. Mean CBF was significantly higher in the heated humidification group (6.36 ± 1.49 Hz) compared to the cold-air nebulization group (3.99 ± 1.39 Hz). Conclusion The data suggest that heated humidification enhanced mucociliary transport leading to a reduced number of required suctioning procedures in the trachea, which may improve postoperative patient care.

Following tracheotomy the airways lack a mechanism of warming and humidifying the inspired air. Nebulization of saline is a common clinical practice to prevent desiccation of airways. The aim of the study was to compare cold-air-nebulization (CAN) and heated humidification (HH) on cilia activity and the necessary healthcare support. Method: Tracheotomised patients (n=19) were randomized to conventional CAN with a jet nebulizer as a control or HH (T 37 C, RH 100%) with high flow of air (30 L/min) delivered with the AIRVO2 blower-humidifier (F&P Healthcare, NZ). The ciliary beat frequency (CBF) in tracheal epithelial cells was measured in vitro using videomicroscopy on day 2, 4, 6, 8 and 10 following the tracheotomy. Number of suctioning procedures per day to clean the trachea from the excessive mucus was assessed. Results: Data are medians (range). CBF was significantly (p