High Concentration Intrinsic Defects in MnSb2Te4.

MnSb2Te4 has a similar structure to an emerging material, MnBi2Te4. According to earlier theoretical studies, the formation energy of Mn antisite defects in MnSb2Te4 is negative, suggesting its inherent instability. This is clearly in contrast to the successful synthesis of experimental samples of MnSb2Te4. Here, the growth environment of MnSb2Te4 and the intrinsic defects are correspondingly investigated. We find that the Mn antisite defect is the most stable defect in the system, and a Mn-rich growth environment favors its formation. The thermodynamic equilibrium concentrations of the Mn antisite defects could be as high as 15% under Mn-poor conditions and 31% under Mn-rich conditions. It is also found that Mn antisite defects prefer a uniform distribution. In addition, the Mn antisite defects can modulate the interlayer magnetic coupling in MnSb2Te4, leading to a transition from the ideal antiferromagnetic ground state to a ferromagnetic state. The ferromagnetic coupling effect can be further enhanced by controlling the defect concentration.

The Double-Deck Viscoelastic Technique: a Novel Surgical Technique to Protect the Corneal Endothelium in Penetrating Keratoplasty of Aphakic Silicone Oil-Dependent Eyes after Severe Ocular Injury.

INTRODUCTION: The purpose of this study is to summarize the benefits of the double-deck viscoelastic technique (DDVT), a novel and cost-effective surgical technique that creates a barrier to hinder silicone oil (SO) from connecting and damaging the corneal endothelium in aphakic and SO-dependent eyes. METHODS: Five SO-dependent and aphakic eyes underwent double-deck viscoelastic embedment and penetrating keratoplasty (PKP) in this retrospective case series. At 1, 6, 12, 18, and 24 months after surgery, clinical outcomes including best corrected visual acuity (BCVA), intraocular pressure (IOP), corneal endothelial cell density (ECD), and double-deck viscoelastic layer imaging were evaluated. A Heidelberg Retina Tomograph confocal microscope was used to measure ECD. Ultrasound biomicroscopy (UBM) was used to image the double-deck viscoelastic layer. RESULTS: Postoperatively, the BCVA of the patients ranged from hand motion detection to 20/200, and their IOP was between 7 and 10 mmHg. The two-deck viscoelastic layer remained mostly static. Patients showed varying degrees of ECD reduction, with ECD loss rates in the first 6 months ranging from 6.7 to 75.8 cells/mm2/month and then declining to 2.2-14.3 cells/mm2/month. CONCLUSION: In SO-dependent aphakic eyes, double-deck viscoelastic embedment could effectively inhibit SO-corneal endothelium interaction. This technique could lower the pace of ECD loss and lengthen the time of corneal transparency, giving aphakic and silicone oil-dependent patients the opportunity to accept PKP surgery and get better vision quality.

Comparisons of the energy efficiency and intraocular safety of two torsional phacoemulsification tips.

BACKGROUND: During cataract phacoemulsification surgery, an Intrepid® balanced (IB) tip can achieve a larger amplitude, which may lead to higher energy efficiency than a Kelman (K) tip when paired with a torsional phaco platform. In this retrospective cohort study, we compared their energy efficiency and damage to the cornea under a new energy setting. METHODS: The medical records of 104 eyes of 79 patients were reviewed, with 47 eyes belonging to the IB group and 57 eyes belonging to the K group. All surgeries were performed on an Alcon Centurion® platform with gravity infiltration. Surgical parameters, visual outcome, central corneal thickness (CCT) changes, and endothelial cell density (ECD) loss rate were recorded and calculated. RESULTS: No significant differences in postoperative best corrected visual acuity (BCVA), intraocular pressure (IOP), total ultrasound time, estimated fluid aspirated, CCT changes, or ECD loss rate were observed between the two groups. We divided the included eyes into soft nucleus and hard nucleus subgroups and found lower cumulative dissipated energy (CDE, 8.15 ± 8.02 vs 14.82 ± 14.16, P = 0.023), cumulative torsional energy (CTE, 8.06 ± 7.87 vs 14.13 ± 13.02, P = 0.027), and cumulative longitudinal energy (CLE, 0.09 ± 0.17 vs 0.69 ± 1.37, P = 0.017) in the IB group than in the K group, implying less energy used and higher energy efficiency of the IB tip. CONCLUSION: Lower CLE in the IB group indicates fewer phaco tip obstructions and a significantly higher capability to conquer hard nuclei with IB tips with statistical significance. With an ultra-perfusion cannula, the balanced tip does not cause more corneal damage.

The facilitating effect of blue light on the antifungal agent susceptibilities of passaged conidia from the ocular-derived Fusarium solani species complex.

The eye is a light-receiving organ and has anatomical advantages to accept phototherapy. Fungi colonizing on the eyes, which cause ocular mycoses, are affected by daily blue light and could easily accept additional light irritation. Ocular mycoses are recalcitrant and blindness-causing eye diseases, and antifungal agent treatments are insufficient. Our team previously found that blue light could inhibit Fusarium solani hyphal growth but promote conidiation. Here, we investigated the antifungal susceptibilities and biological characteristics of the passaged conidia. Twelve Fusarium solani strains (11 ocular-derived strains and 1 standard laboratory strain) were inoculated under blue light (0.5 mW/cm2) and darkness conditions, respectively, to obtain the passaged conidia of blue light group (n = 12) and darkness group (n = 12). Two groups were tested to determine the growth abilities and in vitro antifungal susceptibilities to five antifungal drugs (voriconazole (VRC), amphotericin B (AMB), terbinafine (TRB), caspofungin (CAS), and 5-flucytosine (5FC)), which were examined by microscopy for morphological observation and spectrophotometry for turbidity analysis. The results showed that blue light group passaged conidia were more sensitive to antifungal drugs (AMB, VRC, TRB, and CAS) compared to darkness group. The MIC50 of VRC significantly decreased after blue light treatment (P < 0.05). The fungal inhibition rate significantly increased for VRC, AMB, and TRB in the low concentration range (P < 0.05 or P < 0.01). Blue light did not affect germination or hyphal extension of passaged conidia. These results suggested that blue light could facilitate fungal inhibition effect of AMB, VRC, TRB, and CAS and may improve the therapeutic efficiency in VRC and AMB clinical applications. Blue light phototherapy may provide a new adjuvant approach for the treatment of ocular mycosis.

Preliminary studies of constructing a tissue-engineered lamellar corneal graft by culturing mesenchymal stem cells onto decellularized corneal matrix.

AIM: To construct a competent corneal lamellar substitute in order to alleviate the shortage of human corneal donor. METHODS: Rabbit mesenchymal stem cells (MSCs) were isolated from bone marrow and identified by flow cytometric, osteogenic and adipogenic induction. Xenogenic decellularized corneal matrix (XDCM) was generated from dog corneas. MSCs were seeded and cultured on XDCM to construct the tissue-engineered cornea. Post-transplantation biocompatibility of engineered corneal graft were tested by animal experiment. Rabbits were divided into two groups then underwent lamellar keratoplasty (LK) with different corneal grafts: 1) XDCM group (n=5): XDCM; 2) XDCM-MSCs groups (n=4): tissue-engineered cornea made up with XDCM and MSCs. The ocular surface recovery procedure was observed while corneal transparency, neovascularization and epithelium defection were measured and compared. In vivo on focal exam was performed 3mo postoperatively. RESULTS: Rabbit MSCs were isolated and identified. Flow cytometry demonstrated isolated cells were CD90 positive and CD34, CD45 negative. Osteogenic and adipogenic induction verified their multipotent abilities. MSC-XDCM grafts were constructed and observed. In vivo transplantation showed the neovascularization in XDCM-MSC group was much less than that in XDCM group postoperatively. Post-transplant 3-month confocal test showed less nerve regeneration and bigger cell-absent area in XDCM-MSC group. CONCLUSION: This study present a novel corneal tissue-engineered graft that could reduce post-operatively neovascularization and remain transparency, meanwhile shows that co-transplantation of MSCs may help increase corneal transplantation successful rate and enlarge the source range of corneal substitute to overcome cornea donor shortage.

Bibliometric and visualized analysis of global research on fungal keratitis from 1959 to 2019.

BACKGROUND: Fungal keratitis is one of the leading causes of ocular morbidity. The prognosis of fungal keratitis is poorer than many other forms of keratitis but the research of which relatively lags behind. We conducted a bibliometric and visualized analysis in order to characterize the overall status, general trends and current foci of keratomycosis research field. METHODS: Literature database ranged from 1959 to 2019 was obtained from web of science core collection and analyzed by Citespace and VOSviewer software. RESULTS: A total of 1906 papers of fungal keratitis were retrieved and derived a 27,917 references document set. The number of publications increased rapidly in past 30 years. Cornea was the journal published most papers of keratomycosis. The leading countries were United States of America (USA), India and Peoples Republic of China (PRC), from where came the most productive and most cited institutions and authors. Co-cited reference analysis revealed the most cited manuscripts were concerned about epidemiology or spectrum. Lens-associated Fusarium, amphotericin B, voriconazole, corneal cross-linking, predisposing factor are some of the high frequency topics in clustered co-cited reference analysis and co-occurrence keywords analysis. Burst detection analysis of keywords showed ocular drug delivery was the new research foci. CONCLUSION: From this study, we received an overall view to the current status, trends and hot spots of fungal keratitis research field. Visualized bibliometric analysis is an efficient way for literature learning and useful for future researchers.

Constructing a Novel Three-Dimensional Biomimetic Corneal Endothelium Graft by Culturing Corneal Endothelium Cells on Compressed Collagen Gels.

BACKGROUND: Endothelium allotransplantation is the primary treatment for corneal decompensation. The worldwide shortage of donor corneal tissue has led to increasing pressure to seek an alternative for surgical restoration of corneal endothelium. Compressed collagen (CC) gels have excellent biocompatibility, simple preparation course and easy to be manipulated. This study aimed to form a new biomimetic endothelium graft by CC. METHODS: We expanded bovine corneal endothelial cells (B-CECs) on laminin-coated CC to form a biomimetic endothelium graft. Scanning electron microscope was used for ultrastructural analysis and tight junction protein ZO-1 expression was tested by immunohistochemistry. RESULTS: The biomimetic endothelium graft, we conducted had normal cell morphology, ultrastructure and higher cell density (3612.2 ± 43.4 cells/mm2). ZO-1 localization at B-CECs membrane indicated the bioengineered graft possess the basic endothelium function. CONCLUSIONS: A.biomimetic endothelium graft with B-CECs expanded on CC sheet was constructed, which possessed cells' morphology similar to that of in vivo endothelial cells and specific basic function of endothelium layer. This method provided the possibility of using one donor's cornea to form multiple uniformed endothelium grafts so as to overcome the shortage of cadaveric cornea tissue.

Safety and Efficiency of Trabectome-mediated Trabecular Meshwork Ablation for Chinese Glaucoma Patients: A Two-year, Retrospective, Multicentre Study.

BACKGROUND: The aim of the study was to evaluate the long-term safety and efficacy of the Trabectome for Chinese glaucoma patients. METHODS: This was a multicenter, retrospective, observational study. Glaucoma patients, except those with neovascular glaucoma, with/without a visually significant cataract were enrolled. The patients received Trabectome or a combined surgery with phacoemulsification and intraocular lens implantation. The primary outcome evaluation was a reduction in intraocular pressure (IOP), and the secondary outcomes were a reduction in glaucoma medication, the 2-year success percentages, and complications. Success was defined as an IOP <21 mmHg and at least a 20% IOP reduction from baseline after 3 months for any two consecutive visits, without additional glaucoma surgery. The data were processed using the R Stats Package version 3.0.0. The Wilcoxon test was used to compare the postoperative IOP and the number of glaucoma medications with baselines. The Kaplan-Meier test was used to calculate the 2-year success percentage. The risk factors related to Trabectome failure were determined by logistic regression. RESULTS: A total of 120 glaucoma patients were enrolled. The Trabectome efficiently reduced the IOP from a baseline of 22.8 ± 1.34 mmHg to 17.6 ± 0.96 mmHg, and the use of glaucoma medications from 2.2 ± 0.17 mmHg to 1.4 ± 0.21 in a 2-year follow-up (both, P < 0.01). The overall success percentage was 80%. No risk factor related to Trabectome failure was identified. No vision-threatening complication was observed. Ten patients, who required secondary glaucoma surgery, all reached the target IOP. CONCLUSIONS: In a 2-year follow-up, Trabectome was an efficient and safe procedure for Chinese glaucoma patients.