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As cataract surgery has evolved, intraocular lens (IOL) complications are rare. The purpose of this review was to report the incidence, diagnosis, and management of IOL decentrations, uveitis-glaucoma-hyphema (UGH) syndrome, IOL opacifications, and refractive surprises. Literature review was performed by searching PubMed, MEDLINE, EMBASE, and the Cochrane Controlled Trial Database and the reference lists of original studies as well as reviews. Intraocular lens decentrations and dislocations can appear at any time, particularly in patients with predisposing factors such as pseudoexfoliation, prior vitreoretinal surgery, or trauma. Recognizing when they require surgical intervention for UGH or to improve visual function is critical in limiting long-term sequela. Intraocular lens opacifications such as glistenings rarely require intervention, but others, such as subsurface nanoglistenings, calcifications, or discolorations, may require IOL exchange. Finally, despite our best efforts to enhance measurements and IOL calculations, refractive surprises still occur. Intraocular lens complications are uncommon with modern cataract surgery. A number of these complications require proper identification and care to optimize patient outcomes.

Purpose To determine the efficacy, risk factors for failure, and adverse events of a standalone novel ab externo SIBS microshunt with mitomycin C (MMC) during 1-year follow-up. Design Retrospective, interventional case series. Subjects Glaucomatous eyes with an intraocular pressure (IOP) above target and/or progressing on maximally tolerated medical therapy. Methods Consecutive patients with open-angle glaucoma (OAG) and no previous filtering surgery received an ab externo SIBS microshunt with MMC from July 2015 to November 2017. Main outcome measures were proportion of eyes at 1-year with (1) no 2 consecutive IOP readings >17 mm Hg or clinical hypotony without (complete) or with glaucoma medications (qualified); and (2) at least a 20% reduction from decision IOP. Secondary outcomes included upper IOP thresholds of 14 mm Hg and 21 mm Hg with and without a 20% IOP reduction from baseline, median IOP, medications, risk factors for failure, interventions, complications, and reoperations. Results A total of 164 eyes in 132 patients were included. Complete success was achieved in 76.9% of eyes, qualified success in 92.5%. Complete success was 75.6% for an upper IOP cut-off of 14 mm Hg and 76.9% for 21 mm Hg, and qualified success was 91.9% and 92.5%. MMC dose of 0.2 vs 0.4-0.5 mg/mL (hazard ratio [HR] 2.51; 95% CI 1.12-5.65) and primary open-angle glaucoma vs secondary open-angle glaucoma (SOAG) (HR 2.51; 95% CI 1.01-6.23) represented the only risk factors for failure in multivariable analysis. Needling was performed in 8.5% of eyes. Two eyes received surgical revision, and 1 a reoperation. Conclusions One-year results of the ab externo SIBS microshunt demonstrated promising rates of qualified and complete success, decreased drop use, few complications, and infrequent postoperative interventions.

During the past few years, the need for functionally graded material (FGM) parts has surfaced with the development of material science and additive manufacturing techniques. The Direct Metal Deposition (DMD) process, a metal based additive manufacturing technique, can locally deposit dissimilar metal powders to produce FGM parts. Yet inappropriate mixing ratio of materials without considering the influence of dilution and overlapping effects among layers and tracks and the variation of material properties can result in inaccurate material composition in the fabricated parts when compared to the desired compositions. Within such a context, this paper proposes a design method that links the process parameters to the desired composition of the part based on mathematical models. The proposed scheme is illustrated through a case study of fabricating an iron-nickel FGM part with three-dimensional composition variation. Using the proposed method, the process parameters can be planned prior to the manufacturing process, and the material distribution deviation from the desired one can be reduced.

Tibial interventions for critical limb ischemia are frequent in patients with end-stage renal disease (ESRD) presenting with critical ischemia. The aim of this study was to examine impact of ESRD on the patient-centered outcomes following tibial endovascular Intervention for rest pain.A database of patients undergoing lower extremity endovascular interventions between 2006 and 2016 was retrospectively queried. Patients with rest pain (Rutherford 4) were identified. Patients with claudication (Rutherford 1 to 3) and tissue loss (Rutherford 5 and 6) were excluded. Patients were categorized by the presence or absence of ESRD. Patient-orientated outcomes of clinical efficacy (CE; absence of recurrent symptoms, maintenance of ambulation, and absence of major amputation), amputation-free survival (AFS; survival without major amputation), and freedom from major adverse limb events (MALEs; above ankle amputation of the index limb or major reintervention new bypass graft, jump/interposition graft revision) were evaluated.A total of 829 patients (56% male, average age 59 years; 658 nonhemodialysis [non-HD] and 171 HD) underwent isolated tibial intervention in one leg for rest pain. Technical success was 99% with a median of 2 vessels treated per patient. There was no difference in the distribution of Trans-Atlantic Inter-Society Consensus I lesions, but both the modified Society for Vascular Surgery (SVS) runoff score and the pedal runoff score were worse in the HD group. The 30-day major adverse cardiac events and 30-day MALEs were equivalent in both groups. CE was 38 ± 9% and 19 ± 8% at 5 years for the non-HD and HD groups, respectively (P 0.01). Overall, AFS was 45 ± 8% and 18 ± 9% at 5 years for the non-HD and HD groups, respectively (P 0.01). Freedom from MALE was 41 ± 9% and 21 ± 8% at 5 years for the non-HD and HD groups, respectively (P 0.01).Patients with ESRD who present with rest pain have equivalent short-term outcomes to those not on dialysis but do not achieve long-term satisfactory CE and AFS after isolated tibial intervention for rest pain.

Somatosensory low threshold mechanoreceptors (LTMRs) sense innocuous mechanical forces, largely through specialized axon termini termed sensory nerve endings, where the mechanotransduction process initiates upon activation of mechanotransducers. In humans, a subset of sensory nerve endings is enlarged, forming bulb-like expansions, termed bulbous nerve endings. There is no in vitro human model to study these neuronal endings. Piezo2 is the main mechanotransducer found in LTMRs. Recent evidence shows that Piezo1, the other mechanotransducer considered absent in dorsal root ganglia (DRG), is expressed at low level in somatosensory neurons. We established a differentiation protocol to generate, from iPSC-derived neuronal precursor cells, human LTMR recapitulating bulbous sensory nerve endings and heterogeneous expression of Piezo1 and Piezo2. The derived neurons express LTMR-specific genes, convert mechanical stimuli into electrical signals and have specialized axon termini that morphologically resemble bulbous nerve endings. Piezo2 is concentrated within these enlarged axon termini. Some derived neurons express low level Piezo1, and a subset co-express both channels. Thus, we generated a unique, iPSCs-derived human model that can be used to investigate the physiology of bulbous sensory nerve endings, and the role of Piezo1 and 2 during mechanosensation., This work was supported by N-RENNT of the Ministry of Science and Culture of Lower Saxony to A.V.B., by a Marie Curie Career Integration Grant to A.V.B. (FP7-PEOPLE-2013-CIG, project number 631792, acronym INMA), by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC 2155 “RESIST” – Project ID 39087428, by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - SFB-900 – 158989968 to R.F. (B1) and A.V.B. (B9), and by a Spanish Government project to A.G. (PID2019-108194RB-I00).

Bistable carbon fiber composites, whose bistability arises from having asymmetric fiber layouts in different layers, have shown immense potential for using in shape morphing and adaptive structure applications. While many studies in this field focus on these composite laminates' external shapes at the two stable states, their snap-through behavior of shifting from one stable shape to the other remains a critical aspect to be investigated in complete detail. Moreover, symmetric loading conditions have been extensively studied based on the classical lamination theory, but the asymmetric loading conditions received far less attention. Therefore, this study examines an asymmetric, localized point load on a [ 0 ∘ / 90 ∘ ] bistable laminate and its complex transient deformation during the snap-through. Finite element simulation and experiment results reveal three uniquely different snap-through behaviors — two-step snap, one-step snap, and no snap — depending on the point load location. The localized initiation and propagation of a “curvature inversion zone,” calculated from finite element and digital image correlation results, are directly related to these snap-through characteristics. This study also explored the feasibility of using an extended analytical model of classical lamination theory to qualitatively reproduce the above findings. This model compares three polynomial functions of different orders to approximate the out-of-plane laminate displacement field. This study's results can offer valuable insights into the fundamental mechanics of snap-through behaviors and the actuation designs for the bistable composites for different loading scenarios.

Purpose To determine the incidence rate, principal causes, and clinical course of eyes developing no light perception (NLP) visual acuity (VA) following Boston Keratoprosthesis (B-KPro) type 1 surgery. Secondary objectives include determining the incidence rate, relative risk (RR), and survival probability with respect to NLP outcomes among eyes with congenital aniridia. Design Retrospective, interventional case series. Subjects All patients undergoing B-KPro type 1 surgery between October 2008 and June 2016 by a single surgeon at CHUM – Hopital Notre-Dame. Methods Records of patients having undergone B-KPro implantation were reviewed. Eyes with a final outcome of NLP were further reviewed to determine best recorded postoperative VA, time to NLP onset, clinical course, and principal cause. Descriptive statistics, incidence rates, Kaplan-Meier survival curves, and the RR of NLP outcomes among eyes with aniridia were determined. Statistical significance was defined as P Results Records of 119 patients were included, with an average follow-up of 49.1 ± 26.8 months postoperatively. Nineteen eyes had a final outcome of NLP, representing 16.0%. The incidence rate of NLP was 0.04 cases per eye-year of follow-up. The most common principal causes were inoperable retinal detachment (n = 7, 36.8%), terminal glaucoma (n = 6, 31.6%), and carrier graft melt-related complications (n = 5, 26.3%). The RR of developing NLP among eyes with aniridia was 3.04 ( P = .01). Conclusions No light perception is a devastating but uncommon outcome of B-KPro surgery. Patients with aniridia seem to be at increased risk. In spite of all available medical and surgical interventions, some eyes may still suffer this outcome.

Corneal blindness is a major cause of blindness in the world and corneal transplantation is the only widely accepted treatment to restore sight in these eyes. However, it is becoming increasingly difficult for eye banks to meet the increasing demand for transplantable tissue, which is in part due to population aging. Donor tissue shortage is therefore a growing concern globally and there is a need for alternatives to human donor corneas. Biosynthetic corneal substitutes offer several significant advantages over native corneas: Large-scale production offers a powerful potential solution to the severe shortage of human donor corneas worldwide; Good manufacturing practices ensure sterility and quality control; Acellular corneal substitutes circumvent immune rejection induced by allogeneic cells; Optical and biomechanical properties of the implants can be adapted to the clinical need; and finally these corneal substitutes could benefit from new advances in biomaterials science, such as surface coating, functionalization and nanoparticles. This review highlights critical contributions from laboratories working on corneal stromal substitutes. It focuses on synthetic inert prostheses (keratoprostheses), acellular scaffolds with and without enhancement of endogenous regeneration, and cell-based replacements. Accent is put on the physical properties and biocompatibility of these biomaterials, on the functional and clinical outcome once transplanted in vivo in animal or human eyes, as well as on the main challenges of corneal stromal replacement. Regulatory and economic aspects are also discussed. All of these perspectives combined highlight the founding principles of the clinical application of corneal stromal replacement, a concept that has now become reality.

Poly( l -lactide) and poly( d , l -lactide) samples have been synthesized through ring-opening polymerization. The homological series of two poly(lactide)s have been studied in 1,4-dioxane solutions by a complex of methods: molecular hydrodynamics, molecular optics, NMR, and optical rotation. The 1 H and 13 C NMR spectroscopy and optical rotation proved the different stereo isomeric composition of poly( l -lactide) and poly( d , l -lactide) polymer series. The P- l -LA series are isotactic polymers, whereas the P- d , l -LA polymer series are atactic or syndiotactic ones. The hydrodynamic volume of poly( l -lactide) macromolecules was found to be larger than that for poly( d , l -lactide) macromolecules. Hydrodynamic studies were performed for P- l -LA series in the range of molar masses: 3.5 M × 10 −3 , g/mol d , l -LA series in the range: 1.6 M × 10 −3 , g/mol l -lactide chains in solution exhibit higher equilibrium rigidity than poly- d , l -lactide chains, which is explained by different chain tacticity. For the first time the birefringence of solution of two investigated types of poly(lactide) macromolecules in mechanical and electrical fields was studied. Both birefringence methods demonstrate the net differences between optical properties of P- l -LA and P- d , l -LA chains and confirm the conclusion made from the hydrodynamic study. Comparisons with the literature data concerning intrinsic viscosity values and chain rigidity parameters have been made.