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To show that an immediate vitrectomy with an intravitreal injection of antibiotics can be an effective approach for the treatment of acute endophthalmitis following intravitreal injections. We reviewed all cases of clinical endophthalmitis caused by an intravitreal injection that were treated in our department between March 2012 and November 2019. Only patients that underwent a vitrectomy within 6 h after presentation to the clinic and with a documented visual acuity shortly before the causative event were included. Baseline best-corrected visual acuity (BCVA) before the causative event was compared to BCVA measured within a follow-up period of 8 months (up to 14 months). In total, 30 eyes of 30 patients were included. The BCVA before the intraocular infection was a mean value of 0.55 logMAR, and the BCVA on the day of the endophthalmitis decreased significantly to 1.66 logMAR. Within 2 months following the pars plana vitrectomy (PPV), the mean BCVA improved to 0.83 logMAR. Eight months following PPV (mean value, 8.20 months; SD, 3.59 months), the mean BCVA was 0.63 logMAR. In the last follow-up interval most of the eyes recovered, and the BCVA did not differ significantly from baseline. Two eyes underwent further pars plana surgery during the follow-up period. No enucleation was required. In this study, we have shown that an immediate vitrectomy with subsequent intravitreal injection of antibiotics is an effective option for treating post-injection endophthalmitis and frequently results in recovery of vision; thus, it should be performed as early as possible, where available.

Die infektiose Endophthalmitis nach vorherigen Operationen oder Injektionen des Auges stellt einen medizinischen Notfall dar. Als ursachliche Pathogene finden sich zumeist grampositive Bakterien (Staphylokokken, Streptokokken, Enterokokken), seltener gramnegative Erreger (z. B. Klebsiella pneumoniae, Pseudomonas aeruginosa) und Pilze. Durch eine moderne Infektionsdiagnostik, die neben einer Gram-Farbung und Agarkulturen auch molekulardiagnostische Verfahren beinhaltet, kann in der Mehrzahl der Falle ein kausales Agens nachgewiesen werden, wodurch wiederum eine zielgerichtete Therapie und eine prognostische Abschatzung ermoglicht werden. Bei einer Endophthalmitis werden intravitreal und haufig auch intravenos Antibiotika gegeben, wobei meist die Kombination aus Vancomycin und Ceftazidim zum Einsatz kommt. In diesem Beitrag werden neue Aspekte zur mikrobiologischen Atiologie der Endophthalmitis und ihrer Diagnostik, therapeutische Optionen im Zuge der allgemeinen Resistenzentwicklung sowie Fragen der perioperativen Antibiotikaprophylaxe vorgestellt und diskutiert.

Postoperative endophthalmitis is one of the most feared complications for ophthalmologists, and the number of infections after intraocular procedures have been increasing. Nonetheless, a prompt intervention can result in the recovery of vision. In the past, endophthalmitis after cataract surgery was accountable for the majority of cases but is becoming less frequent due to the progress of surgical techniques and demographic developments with a steadily increasing number of intravitreal injections. In this article, the different forms of postoperative endophthalmitis are assessed in terms of pathophysiology and their specific characteristics depending on their etiology.

Operation of high-resolution, broadband, antisubmarine warfare sonars in littoral waters is challenging, since the presence of sea mounts, underwater ridges, and other topographic features causes increased false alarm rates. Two important contributors to the raised false alarm rate are the signal-processing induced phenomenon called false alarm rate inflation (FARI) and the presence of sonar clutter, also referred to as non-Rayleigh distributed matched filter envelope in literature. Conventional constant false alarm rate (CFAR) algorithms fail to achieve a constant false alarm rate in all ranges and bearing in the presence of such effects. Given sufficient information on the bathymetry and the bottom properties, the occurrence of FARI may be estimated through the use of an acoustic model. This allows for more accurate estimates of the false alarm rate. Through measurements, the scatterer statistics for a given sonar in a given area may be estimated. Combining a FARI predicting scheme with knowledge on the scatterer statistics allows the estimation of the probability of false alarm in the presence of both FARI and sonar clutter. Here, we propose a new detection scheme that employs this approach to estimate a range- and bearing-dependent threshold that can be applied on normalized sonar data to achieve a CFAR even in the presence of FARI and clutter. The performance of the method is assessed through the use of receiver operating characteristic curves and is shown to outperform conventional CFAR algorithms, such as the cell averaging, greater of, and ordered statistics CFAR processors. The method is tested on both recorded and synthetic data. The robustness of the method is tested using synthetic data by introducing errors in the topography, sound speed, and scatterer statistics when estimating the probability of false alarm. The performance of the method decreases when introducing these errors, but it still outperforms the conventional CFAR processors.

The purpose of this study is to compare the safety and clinical results of descemet membrane endothelial keratoplasty (DMEK) in topical, peribulbar or general anesthesia. This is a retrospective, post hoc matched study of 120 patients having received DMEK surgery with different types of anesthesia (n = 40 topical, n = 40 peribulbar, n = 40 general anesthesia). Endpoint criteria were intraoperative complications, endothelial cell count, central corneal thickness and graft rejection rate, rebubbling rate and best-corrected visual acuity after 1, 3 and 6 months. The group with topical anesthesia showed more often intraoperative difficulties such as vitreous pressure (p

Akute Toxizitat von perfluorokarbonierten Flussigkeiten (PFCL) in der Netzhautchirurgie ist ein relevantes Problem, das auf Verunreinigungen im Medizinprodukt zuruckzufuhren ist. Dieser Beitrag gibt eine Ubersicht uber die aktuelle Problematik, mogliche Erklarungen, Wechselwirkungen mit anderen Medizinprodukten und Ansatze zur verbesserten Patientensicherheit. Toxizitat entsteht durch Verunreinigungen im Rohmaterial, kann aber auch durch Wechselwirkungen mit anderen Medizinprodukten oder Medikamenten entstehen. Die bisherigen Testverfahren bilden den ophthalmologischen Anwendungsfall nicht ideal ab, es gibt aber vielversprechende Aktivitaten, um die Weichen fur die Zukunft zu stellen. Der Einsatz von PFCL in der Netzhautchirurgie ist generell als sicher einzustufen. Die Anwender sollten auf die Qualitat ihrer Medizinprodukte achten.

Mit der Einfuhrung der flussigen Perfluorkohlenstoffe (PFCL) kam es zu einem deutlichen Wandel in der vitreoretinalen Chirurgie. Auch komplizierte Netzhautablosungen konnten so zuverlassig und erfolgreich behandelt werden. Die Kombination einer Vitrektomie mit dem Einsatz des PFCL war neben dem technischen Refinement einer der entscheidenden Faktoren fur den anhaltenden Erfolg der Pars-plana-Vitrektomie (ppV). Die flussigen Perfluorkohlenstoffe haben durch das breite Einsatzspektrum und den positiven intraoperativen Einfluss einen festen Platz in der vitreoretinalen Chirurgie eingenommen. Bei regelrechtem und intelligentem Einsatz kann der PFCL als dritte Hand des Netzhautchirurgen gesehen werden. Entgegen der vielfachen Skepsis ist die momentan diskutierte Toxizitat bei kurzfristigem Einsatz von PFCL zu vernachlassigen.

Evaluating the effect of a single peripheral triangular mark to ensure the correct anterior–posterior graft orientation in DMEK. Retrospective study of patients scheduled for DMEK due to Fuchs endothelial dystrophy and divided into 2 study groups: Group −M (n = 184) had no mark of the EDM (Endothelial Descemet membrane) and group + M (n = 193) had a triangular peripheral mark. Follow-up time was 1 year after surgery. The postoperative graft turning and Re-DMEK rate could be significantly reduced by the use of a peripheral mark (p = 0.002, p = 0.001, respectively). Re-DMEK due to primary graft failure was significantly associated with prior graft turning (p

PURPOSE To demonstrate possible complications of a new IOL (intraocular lens) for sutureless secondary scleral implantation and modifications of the surgical technique to optimise outcomes. METHODS Retrospective study of 16 eyes (16 patients) who underwent a secondary IOL implantation using the Carlevale IOL (Soleko, Italy) with two anchor haptics for intrascleral implantation (mean follow-up 2.2 months). RESULTS Visual acuity did not improve statistically significantly postoperatively (p = 0.601). Seven (44 %) patients suffered from postoperative hypotonia (intraocular pressure < 5 mmHg) during the first three postoperative days. CONCLUSION Due to the early postoperative hypotony, we decided to modify the surgical technique. We present several suggestions to optimize the technique and outcome like positioning the sclerotomies at the 2 and 8 o'clock positions, using 27 G trocars only and suturing the frown incisions using self-resorbing sutures.

The automation of medical documentation is a highly desirable process, especially as it could avert significant temporal and monetary expenses in healthcare. With the help of complex modelling and high computational capability, Automatic Speech Recognition (ASR) and deep learning have made several promising attempts to this end. However, a factor that significantly determines the efficiency of these systems is the volume of speech that is processed in each medical examination. In the course of this study, we found that over half of the speech, recorded during follow-up examinations of patients treated with Intra-Vitreal Injections, was not relevant for medical documentation. In this paper, we evaluate the application of Convolutional and Long Short-Term Memory (LSTM) neural networks for the development of a speech classification module aimed at identifying speech relevant for medical report generation. In this regard, various topology parameters are tested and the effect of the model performance on different speaker attributes is analyzed. The results indicate that Convolutional Neural Networks (CNNs) are more successful than LSTM networks, and achieve a validation accuracy of 92.41%. Furthermore, on evaluation of the robustness of the model to gender, accent and unknown speakers, the neural network generalized satisfactorily.

PURPOSE To investigate the clinical outcome and complication rate of precut Descemet membrane endothelial keratoplasty (DMEK) in two different culture conditions, dextran-containing and dextran-free medium, and compare the results with the current standard DMEK procedure. METHODS A prospective study of 32 eyes suffering from Fuchs endothelial dystrophy were scheduled for DMEK with a follow-up of one year. The eyes were divided into four subgroups. Group + D (n = 7) received a precut DMEK stored in dextran-containing transport medium, and Group - D (n = 9) received a precut DMEK without dextran-containing medium. The respective fellow eyes received a standard DMEK (S) (preparation directly prior to surgery) stored in dextran-containing medium (S-D + ; n = 7) or without (S-D-; n = 9). RESULTS Clinical outcome (visual acuity, endothelial cell count, central corneal thickness) and rebubbling rate were comparable for all four groups. None of the patients had a graft failure. CONCLUSION The preliminary data of the pilot study show that precut liquid-bubble DMEK leads to comparable clinical results regardless of dextran-containing or dextran-free organ culture medium and is further comparable to the standard DMEK procedure.

This study aims to analyze the success rate and functional outcome after revision surgery of persistent idiopathic full-thickness macular holes in a large patient cohort and to identify the optimal tamponade strategy and the value of new adjunctive manipulation techniques for persistent macular hole (pMH) closure. Retrospective, comparative, non-consecutive case series of all revisional surgeries for idiopathic pMH between 2011 and 2019 at the Eye Clinic Sulzbach were identified. Of 1163 idiopathic MH surgeries, 74 eyes of 74 patients had pMH. Of those, group 1 (n = 38) had vitrectomy with tamponade alone (20% sulfur hexafluoride gas, 15% hexafluoroethane gas, silicone oil 5000, Densiron®), while group 2 (n = 36) included tamponade with adjuvant manipulation (internal limiting membrane (ILM) translocation, subretinal fluid injection, epiretinal amniotic membrane, free retina graft, or autologous blood). Main statistical outcomes were anatomic closure rate, visual acuity (VA), minimum linear diameter (MLD), and base diameter (BD). Overall total anatomical success rate was 81.1% and mean VA improved 3.5 lines from LogMAR 1.03 ± 0.30 to 0.68 ± 0.38 (p

Active sonar performance is highly dependent on the surrounding environment. Conventional detection algorithms apply thresholds to acoustic data passed through a normalizer in order to detect targets. These methods fail to fully exploit available knowledge of the environment, which leads to higher false alarm rates than necessary, particularly in littoral environments. Furthermore, they do not exploit negative information, e.g. the significance of the repeated lack of threshold crossings in a given area. Sonar performance models may estimate both the probability of detection and false alarm in a known environment. Proper exploitation of this data allows for reduced false alarm rates in cluttering and reverberating environments. Furthermore, areas lacking threshold crossings and with high probability of detection, may be classified as target free. Bayesian occupancy grids is a probabilistic approach that takes into account both sensor information and prior information of surrounding walls or topography for localization of robots. Here we apply the method on synthetic sonar data combined with a sonar performance model. The synthetic sonar data contains moving and stationary targets in a littoral environment. The method's performance is compared to conventional algorithms, and its robustness to errors in the sound speed profile used in the modelling is assessed.

When utilising high-resolution broadband sonars in littoral waters, the sonar image can become highly cluttered with false alarms and tracks. These false alarms usually originate from a myriad of different environmental sources, such as seamounts, underwater ridges, and other topographical features, or man-made objects, such as pipelines. Automatic classification algorithms may be developed through supervised learning and be employed for reducing the amounts of false alarms. However, this requires large amounts of labelled data. This is particularly the case for methods using deep neural networks. Labelling is a tedious and time consuming endeavour. Here we propose a method for automatic recognition of sonar tracks on known navigational paths by utilising known parameters, such as bearing, range, course, and velocity, from both the navigational and sonar track. In this work we present the method, perform a parameter study and a sensitivity analysis. Due to the limited amount of sonar data with corresponding known navigational data from possible target vessels, and the minimal maneuvering usually performed by such vessels, the sonar data used in this study is synthetic containing several synthetic target vessels. We find that the method is robust and can correctly match up to 84% of tracks on a navigational path while discarding 99.5% of false tracks. Although the ratio of false to target tracks in the classified data set should ideally be even lower for supervised learning, the large reduction in false tracks will ease the process of manually removing the remaining 0.5% drastically.

PURPOSE To analyse the factors influencing the primary patency of clear corneal incisions in femtosecond laser-assisted cataract surgery (FLACS). METHODS In this prospective single-centre study, the graphical user interfaces of 159 patients undergoing femtosecond laser-assisted cataract surgery were documented by video. Subsequently, the quality of limbus detection along with the incidence of vessels and an arcus lipoides were assessed by a grading system and analysed in relation to the primary patency of the incisions. In particular, the differences between a superior and a temporal main incision were analysed. RESULTS The designed grading system could be applied in all cases without any problems. Limbus detection was highly inhomogeneous but had no influence on the patency of the incisions (46.3% poor, 18.4% moderate, 35.1% good). The characteristics of the arcus lipoides had little influence on the patency of the main incisions. Pronounced vascular ingrowth caused more tissue bridges but did not reduce the patency of the incisions. Temporal access was generally easier to open than a superior one (97.1% versus 88.9%). CONCLUSION We showed a patency rate of superior FLACS incisions of over 97% with the Femto LDV Z8 in our study. Temporal main incision is preferable to superior main incision in more difficult situations. The new grading system is suitable for further studies to provide information on the quality of the incision.

Purpose: The aim of this article is to report an unusual case of postoperative graft loss into the vitreous cavity after Descemet membrane endothelial keratoplasty (DMEK) in a patient with an unstable iris-lens diaphragm (scleral-fixated intraocular lens [sf-IOL]) and its successful retrieval with a favourable outcome. Methods: This is a retrospective case report. Results: DMEK procedure was performed in a vitrectomized eye of an 80-year-old woman with pre-existing sf-IOL due to pseudophakic bullous keratopathy. In the setting of an inadvertently created oversized Ando iridectomy and unstable iris-lens diaphragm due to sf-IOL, repeated loss of an anterior chamber gas tamponade occurred. At the 3rd postoperative day, the patient noticed a change in visual perception, and we could detect a loss of the graft into the vitreous via B-scan ultrasound. A 23-G vitrectomy was performed promptly to recover the graft using a bimanual hand-over-hand technique. Six months after DMEK, the patient had a clear cornea without dehiscences with a central corneal thickness of 533 µm and endothelial cell count of 1,219 cells/mm2. Conclusions: This case demonstrates the possibility of graft recovery from the vitreous after DMEK and subsequent corneal clearing despite unstable iris-lens diaphragm and vitrectomized eye.

Trotz der technischen Fortschritte in der Ablatiochirurgie besteht nach wie vor ein signifikantes Reablatiorisiko, zudem ist die visuelle Rehabilitation durch die Endotamponaden verlangsamt. Hydrophobe Tamponaden agieren uber einen Auftriebsvektor, dadurch kommt es zur Ansammlung von proinflammatorischen Zytokinen gegenuber dem Auftriebsvektor. Die bisherigen Ansatze von hydrophilen Endotamponaden sind vielversprechend, da sie einen moglichen Losungsansatz fur die genannten Probleme der Ablatiochirurgie darstellen.

Purpose: To compare the clinical outcomes following Descemet’s membrane endothelial keratoplasty (DMEK) with 100% air tamponade versus 10% sulfur hexafluoride (SF6) tamponade.Methods: Retrospective analysis of 108 consecutive DMEK cases subdivided by anterior chamber tamponade with 54 eyes receiving 10% SF6 and 54 eyes receiving 100% air injection. A post-hoc matched analysis revealed no statistically significant differences between the groups. The main outcome measurements were the complication rate, including intra- and postoperative complications and graft detachment rate requiring re-bubbling. Clinical outcome included best-corrected visual acuity (BCVA), endothelial cell count (ECC), and central corneal thickness (CCT) measured 1, 3, and 6 months after DMEK surgery.Results: The graft detachment rate with consecutive re-bubbling was 18.5% in the air group and 22.2% in the SF6 group (p = 0.2). Remaining small peripheral graft detachments with a clear cornea occurred more often in the 100% air g...

Retinal toxicity/biocompatibility of medical devices in direct contact with the retina is an important subject for clinicians and scientists. As these effects are not very frequent, there is also a relative lack of information for many clinicians. The past has taught us multiple times that there is a significant safety problem associated with severe loss of vision in affected patients. In this review, we want to classify medical products that are used in the back of the eye, describe recent examples of toxicity, critically reflect on the regulations that exist and suggest improvements that can be done to ensure patient safety without hindering innovation. Methods: Critical review of the recent papers and personal experience of the authors in this issue. Medical devices used in the back of the eye and recent examples of toxicity are described, regulations that exist are critically reflected and improvements suggested that can ensure patient safety without hindering innovation. Results: There is clear evidence of toxicity after intraocular surgery in any category. Some cytotoxic indirect methods have failed in detecting this toxicity. Some ISO rules do not seem appropriate. Postmarketing safety is missing. There is little data on this issue. Conclusions: The absence of a clear regulation of the production, purification and evaluation of the toxic effects of the medical devices supposes the possibility that products are not sufficiently safe to obtain the CE mark.

Descemet membrane endothelial keratoplasty (DMEK) has been improved over the last decade. The aim of this study was to compare the clinical outcome of the recently introduced liquid bubble method compared to the standard manual preparation.This retrospective study evaluated the outcome of 200 patients after DMEK surgery using two different graft preparation techniques. Ninety-six DMEK were prepared by manual dissection and 104 by the novel liquid bubble technique. The mean follow-up time was 13.7 months (SD ± 8, range 6-36 months).Best corrected mean visual acuity (BCVA) increased for all patients statistically significant from baseline 0.85 logMAR (SD ± 0.5) to 0.26 logMAR (SD ± 0.27) at the final follow-up (Wilcoxon, p = 0.001). Subgroup analyses of BCVA at the final follow-up between manual dissection and liquid bubble preparation showed no statistically significant difference (Mann-Whitney U Test, p = 0.64). The mean central corneal thickness was not statistically different (manual dissection: 539 µm, SD ± 68 µm and liquid bubble technique: 534 µm, SD ± 52 µm,) between the two groups (Mann-Whitney U Test, p = 0.64). At the final follow-up, mean endothelial cell count of donor grafts was statistically not significant different at the final follow-up with 1761 cells/mmRegarding the clinical outcome, we did not find a statistical significant difference between manual dissection and liquid bubble graft preparation. Both preparation techniques lead to an equivalent clinical outcome after DMEK surgery.

Wir berichten uber einen Fall eines akuten schmerzlosen monokularen Visusverlusts bei einem 53-jahrigen Mann. Eine interdisziplinare Ursachenabklarung ergab keinen Hinweis auf die Ursache des Arterienastverschlusses. Eine Reevaluierung der Anamnese ergab einen moglichen Zusammenhang mit einer Phosphodiesterase-5-Inhibitor (PDE 5-Inhibitor) Einnahme. Kritisch betrachtet erfolgt eine Literaturrecherche von okularen Beteiligungen nach PDE-5-Inhibitoren.

Purpose The purpose of this study was to investigate the safety and efficacy of phacocanaloplasty with suprachoroidal drainage (PCscD) and to compare its intraocular pressure (IOP)-lowering and drug-sparing effect to canaloplasty with suprachoroidal drainage (CscD). Methods The study retrospective interventional study included patients with open-angle glaucoma or secondary forms of glaucoma who underwent either CscD or PCscD between the year 2011 and 2014 in Knappschaft Eye Clinic Sulzbach. Primary end-points were IOP reduction and the number of IOP-lowering medication after 12 months. Secondary end-points were intraoperative and postoperative complications. Results A total of 328 eyes were included, 193 were treated with CscD and 135 underwent PCscD. Canaloplasty with scD achieved an IOP reduction of 37.0% (from 20.9 ± 3.6 mmHg to 13.2 ± 2.6 mmHg) after 1 year, whereas PCscD showed a significant higher reduction of 47.4% (from 23.2 ± 5.1 mmHg to 12.2 ± 1.7 mmHg). Reduction in IOP-lowering medication was higher after PCscD (from 3.6 ± 0.6 to 0.2 ± 0.5) than after CscD (from 3.5 ± 0.8 to 0.7 ± 1.0). Twelve months after surgery 55.5% in the CscD group and 80.2% in the PCscD group were free of IOP-lowering medication. In both groups, no severe or sight-threatening complications occurred. Conclusion Combining cataract surgery and CscD achieves a higher IOP reduction, and patients postoperatively need less IOP-lowering medication than after CscD alone.

ZusammenfassungDie suprachoroidale Hydrogelplombe ist ein neues, einfaches und sicheres Verfahren zur Behandlung der Netzhautablösung. Die technischen Vorteile der modernen Vitrektomie und der klassischen Buckelchirurgie sollen in diesem operativen Ansatz vereint werden. Die Technik kann additiv in Kombination mit der Vitrektomie oder als „stand-alone procedure“ angewendet werden. Als geeignetes Tamponadematerial hat sich das quervernetzte Hydrogel mit einer Resorptionsdauer von bis zu 8 Wochen herausgestellt. Es werden noch weitere Untersuchungen mit Langzeiterfahrungen empfohlen, die zu einer weiteren Verbreitung der suprachoroidalen Hydrogelplombe als operatives Verfahren zur Behandlung der Netzhautablösung führen sollten.

To introduce a methodical description and to investigate first clinical safety of a novel liquid interface technology for femtosecond laser-assisted perforating keratoplasty, maintaining the corneal curvature without applanation of the cornea.In this pilot study six patients received a femtosecond laser keratoplasty using a new liquid interface providing a non-applanating trephination. Clinical outcomes were evaluated 1, 3 and 6 months after surgery.All procedures were performed without complications and donor and recipient corneas could be aligned without problems, even in cases of advanced keratoconus. Although this initial pilot study investigated clinical safety, a positive effect on postoperative astigmatism was observed.We could show in this first pilot study that a hand-held liquid patient interface in combination with a femtosecond laser has a preliminary safety and reliability in penetrating keratoplasty.

To investigate the impact of different patient interface (PI) diameters and different vacuum levels on the suction stability during vacuum application for femtosecond laser-assisted LASIK.Break-away forces as a marker for suction stability were measured by an automated test bench set-up. The test bench was based on a customized stamp connected to a digital load cell. Three flat applanating PI with different diameters (8.5, 9.5 and 10.0 mm) and four different vacuum levels (500, 600, 700 and 800 mbar) were investigated using the FEMTO LDV Z8 (Ziemer Ophthalmic Systems AG, Switzerland).Mean break-away force was 5.23N (±0.99N) using the 8.5 mm PI and 500 mbar vacuum, 8.18N (±1.39N) using the 8.5 mm PI and 800 mbar, 3.37N (±0.56N) using the 10.0 mm PI and 500 mbar, and 6.14N (±0.68N) using the 10.0 mm PI and 800 mbar vacuum (p.001; CI95%). Increasing the PI diameter from 8.5 to 10.0 mm resulted in a 28.89% (+1.97 ± 1.02N) lower break-away force (p.001) when using default vacuum settings (700 mbar) compared to increasing vacuum from 500 to 800 mbar, which resulted in a 60.37% (+1.95 ± 1.40N) higher mean break away force (p.001).The vacuum level and the diameter of the PI showed significant impact on suction stability measured as break-away force during flat applanating docking for corneal and refractive surgery. Break-away forces were inversely related to the PI diameter and directly to the vacuum level. Increasing the PI diameter by one step or reducing vacuum by 100 mbar resulted in a comparable decrease of break-away forces. Therefore, the surgeon could potentially maintain stabile suction by increasing vacuum when choosing a larger PI diameter to obtain a larger treatment zone. Furthermore, reduction of the PI diameter and/or increasing vacuum could help improving suction stability in situations of poor suction and in situations with increased risk of suction loss during LASIK.

A stable and reliable vacuum is crucial for the correct planning and performance of femtosecond laser-assisted cataract surgery (FLACS) in order to avoid complications such as suction loss and cyclorotation. This study investigates, for the first time, the impact of different vacuum levels on the stability of the application of a liquid patient interface for FLACS in view of break-away forces. Break-away forces were measured using a multifunctional material testing machine with a mounted digital manometer. Sixteen porcine eyes were docked to the patient interface of a femtosecond laser platform (FEMTO LDV Z8), and the impact of different vacuum levels between 300 and 500 mbar investigated. Mean break-away forces for each vacuum level were as follows: 1.78 N (± 0.58 N) for 300 mbar; 2.24 N (± 0.68 N) for 350 mbar; 2.66 N (± 0.68 N) for 400 mbar; 2.86 N (± 0.77 N) for 420 mbar; and 3.49 N (± 0.86 N) for 500 mbar. The stability increases with the vacuum in a nearly linear manner. Vacuum levels higher than 500 mmHg and lower than 350 mmHg are not recommended for FLACS.

Background Clinical outcome after successful reorientation of an upside-down implanted DMEK (Descemet Membrane Endothelial Keratoplasty) graft 4 weeks after initial transplantation. Case presentation A 71-year-old woman presented with Fuchs’ endothelial corneal dystrophy for DMEK. After initial DMEK the donor graft was fully attached and well centred during intracameral gas filling. When the gas bubble was fully resorbed the graft started to detach. Therefore, two intracameral gas injections were consecutively performed. During the second re-bubbling, an upside-down orientation was observed and so the graft was flipped, centred, re-attached and finally stabilized by an intracameral gas bubble. Three weeks after reorientation slit lamp examinations showed a well centred and attached graft, endothelial cells that started functioning and a patient’s visual acuity of 20/40. Visual acuity increased to a 20/32 vision in the observed eye three months later and further improved to 20/20 6 months after reorientation and stayed stable between 20/32 and 20/20 during the remaining 15 months of follow-up, with a clear and well-attached graft. Conclusion Reorientation of an upside down DMEK graft was successful even 4 weeks after initial DMEK. Visual recovery and endothelial cell count increase were stepwise noticed during the first 6 months and 15 months after reorientation, respectively. Finally a favourable outcome with 20/32 to 20/20 vision at least 6 months after graft reorientation was achieved. Therefore, restoring full graft function could last several weeks or even months following (late) reorientation of an upside-down DMEK graft.

In anti-submarine warfare, high resolution, broadband sonars are commonly used. This, however, might challenge the sonar operator in littoral environments as the sonar image often becomes cluttered due to false alarms. The origin of these false alarms can be anything from topographical features in general to man made objects, such as pipelines. The large amount of false alarms in littoral waters makes correct classification of contacts difficult. Normally, a fixed detection threshold on signal-to-noise ratio is employed in order to reduce clutter and make classification feasible. For continuous wave echoes, the same fixed threshold method can be used on Doppler to reduce the false alarm rate. However, this will also lower the probability of detecting a valid target, such as a submarine. A better method for reducing the false alarm rate with a lower reduction of detection probability, is by applying a variable threshold that is dependent on both SNR and Doppler, simultaneously.Here we apply different dependencies between SNR and Doppler in order to find the best target to false detection ratio possible. Due to the classified nature of sonar data with submarines, the dataset used is synthetic with several synthetic submarines present. The various dependencies will be tested on several different synthetic submarines (small, large, fast, slow) to verify that they are not also submarine dependent, as this would reduce the usefulness of the SNR-Doppler dependency significantly.We find that using thresholds that consider both SNR and Doppler simultaneously will in most cases perform much better than a single fixed threshold. Furthermore, the effect on using SNR and Doppler dependent thresholding before clustering has a huge impact on the presented sonar image, improving the amount of false tracks greatly. Finally, we find an unexplained dip in false alarms at a narrow Doppler interval in our synthetic data. This dip will most likely benefit simpler thresholding methods more than the more advanced. Hence, this dip should be understood before recomending using the simpler fixed SNR and Doppler method in false alarm rate reduction.

Use of high–resolution sonars in littoral environments generally result in high false alarm rates both due to false alarm rate inflation and non–Rayleigh reverberation. High false alarm rates may be handled by simply increasing the threshold used in the detection algorithm, but this would also reduce the probability of detecting an actual target.Automatic classification is an alternative and commonly used approach for false alarm reduction. Generally, training of classification algorithms requires large amounts of data from diverse environments and different targets. This is particularly important for classifiers based on deep learning.The lack of sufficient amounts of data may be solved through data augmentation. Here we propose a method for generating synthetic sonar data. The synthetication employs an acoustic model to estimate both reverberation and target echo impulse responses. The 2D acoustic raytracer used models the acoustic propagation through a vertical cross section of the ocean. The method runs the model in all directions and takes into account the beam pattern and Doppler effects in order to estimate a 3D (bearing, range, Doppler) reverberation data set for each transmission. Higher order statistics are included by employing a K-distributed random process in the reverberation and noise modelling. In the presence of a target, the impulse response function in Lybin is used to estimate the contribution of the target to each beam, range, and Doppler bin.As an example, a deep neural net is trained to separate false alarms from target detections using synthetic data generated by the proposed method. The resulting sonar data is normalised, thresholded, and clustered. The trained classifier is able to remove 89% of the false alarms while keeping 90% of the target detections.