Association of Paracentral Acute Middle Maculopathy with Visual Prognosis in Retinal Artery Occlusion: A Retrospective Cohort Study.

Background: The association between paracentral acute middle maculopathy (PAMM) and visual acuity in patients with retinal artery occlusion (RAO) is unknown. This study explored the clinical features and prognostic factors for visual acuity of RAO accompanied by PAMM. Methods: This retrospective study included patients with RAO who underwent FFA and OCT examinations at Shenzhen Eye Hospital from July 2015 to June 2019. The changes in vision and macular structure were observed. Results: Eighty-eight patients were included. There were 58 patients (65.9%) with central RAO (CRAO) and 30 (34.1%) with branch RAO (BRAO). Fifty-two eyes were diagnosed with PAMM, of which 33 eyes (63.5%) were from CRAO patients and 19 (36.5%) were from BRAO patients. At diagnosis, the PAMM group had significantly better logMAR BCVA values than the no-PAMM group (median (IQR), 1.35 (0.725-2) vs. 2.15 (1.47-2.3), P=0.002). In addition, the PAMM group had significantly better logMAR BCVA values during follow-up than the no-PAMM group (median (IQR), 1 (0.05-2) vs. 2 (1.15-2.3), P=0.001). After adjustment for age, gender, CRAO/BRAO, comorbidities, and symptom duration, PAMM was associated with good visual acuity improvement (RR = 3.29, 95% CI: 1.29-8.37, P=0.013). Conclusion: PAMM was associated with good visual acuity improvement during follow-up in patients with RAO.

Reattachment After Foldable Capsular Vitreous Body Implantation in Severe Retinal Detachment Eyes.

Purpose: To evaluate the clinical effectiveness and safety of foldable capsular vitreous body (FCVB) implantation for severe retinal detachment. Methods: A retrospective analysis was performed on 26 patients with severe ocular trauma and one with recurrent retinal detachment. Clinical data-including surgery success, complications, retinal reattachment, vision, and intraocular pressure (IOP)-were analyzed for patients who underwent 23G pars plana vitrectomy and FCVB implantation combined with silicone oil tamponade. Results: The mean follow-up period was 10.44 ± 2.68 months. All surgeries were smooth; the FCVBs were properly positioned and supported the retina well, and the retinal reattachment rate reached 92.59%. At the six-month follow-up, preoperative (1.30 ± 1.20) and postoperative (0.63 ± 0.79) vision was significantly different (t = 3.03, P = 0.005), and the postoperative IOP (7.93 ± 3.57 mm Hg) was lower than the preoperative IOP (13.98 ± 10.72 mm Hg) (t = 2.74, P = 0.01). Among 20 patients followed up for >12 months, preoperative (1.20 ± 0.95) and postoperative (0.75 ± 0.91) visions were significantly different (t = 1.831, P = 0.005), and the postoperative IOP (9.85 ± 6.48 mm Hg) was lower than the preoperative IOP (14.85 ± 12.17 mm Hg) (t = 1.82, P = 0.01). No endophthalmitis, sympathetic ophthalmia, and rejection of FCVB occurred during follow-up. Conclusions: FCVB combined with silicone oil tamponade showed good efficacy and safety in severe retinal detachment treatment during the follow-up period. Translational Relevance: Vitreous substitution is deemed a highly challenging and interesting research topic in ophthalmology. Traditional method such as silicone oil tamponade often causes various complications such as silicone oil emulsification, silicone oil migration, and corneal degeneration. The foldable capsular vitreous body as a novel vitreous substitute combined silicone oil injection into it can stay in the eyeball for a long time without obvious complications.

Efficacy and Safety Outcomes of Intravitreal Dexamethasone Implant Therapy for the Treatment of Adult Coats' Disease.

PURPOSE: To evaluate the efficacy and safety outcomes of dexamethasone intravitreal implant in patients with Stage 3A Coats' disease. METHODS: A consecutive case series of adult Coats' disease managed with or without intravitreal dexamethasone implant (Ozurdex®, Allergan Inc., Irvine, California, USA) injection was retrospectively evaluated. The medical records of all included patients with a minimum follow-up of 6 months were reviewed. The patients were divided into two groups according to the application of dexamethasone implant as a DEX (+) group and DEX (-) group. Laser photocoagulation, anti-VEGF agents, and vitrectomy were performed if necessary. The primary outcomes included best-corrected visual acuity (BCVA), central retinal thickness (CRT), and intraocular pressure (IOP) at month 6. Resolution of the exudative retinal detachment (ERD), subretinal fluid (SRF), and vitreous hemorrhage (VH) was also collected. RESULTS: Ten eyes (10 patients) with Stage 3A Coats' disease were included, and the mean follow-up time was 9.70 ± 4.42 months. The mean age was 44.20 ± 7.42 years, and 80% were male. Six eyes (6 patients) received intravitreal injection of Ozurdex were included in the DEX (+) group, while the other 4 eyes in the DEX (-) group. No significant difference of baseline characteristics including BCVA, CRT, IOP, and follow-up time can be defined between DEX (+) and DEX (-) groups. For the patients in the DEX (+) group, a significant improvement of BCVA was observed from the baseline of 1.28 ± 0.58 to 0.84 ± 0.66 logMAR at month 6 (P=0.03), while the CRT decreased from 970.33 ± 696.49 to 421.00 ± 275.76 µm (P=0.067). For the DEX(-) group, BCVA changed from 0.76 ± 0.74 to 0.96 ± 0.60 logMAR at month 6 (P=0.066), while the CRT from 382.75 ± 17.68 to 412.75 ± 195.53 µm (P=0.525) with no significant difference. IOP was elevated from 13.15 ± 1.74 mmHg at baseline to 18.05 ± 3.57 mmHg at month 6 with a P value of 0.02 for the DEX(+) group and from 14.48 ± 1.70 to 18.83 ± 4.06 mmHg (P=0.076) for the DEX (-) group. After a mean follow-up of 9.70 months, 5/6 (83.3%) eyes in the DEX (+) group and » (25%) eye in the DEX (-) group achieved reattachment of ERD. CONCLUSION: Intravitreal dexamethasone implant therapy is effective for adult Stage 3A Coats' disease, which provides a new treatment option for ophthalmologists.

Hierarchical MoO3/SnS2 core-shell nanowires with enhanced electrochemical performance for lithium-ion batteries.

Two-dimensional (2D) tin disulfide (SnS2) is a promising anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity. The main challenges associated with the SnS2 electrodes are the poor cycling stability and low rate capability due to structural degradation in the discharge/charge process. Here, a facile two-step synthesis method is developed to fabricate hierarchical MoO3/SnS2 core-shell nanowires, where ultrathin SnS2 nanosheets are vertically anchored on MoO3 nanobelts to induce a heterointerface. Benefiting from the unique structural and compositional characteristics, the hierarchical MoO3/SnS2 core-shell nanowires exhibit excellent electrochemical performance and deliver a high reversible capacity of 504 mA h g-1 after 100 stable cycles at a current density of 100 mA g-1, which is far superior to the MoO3 and SnS2 electrodes. An analysis of lithiation dynamics based on ab initio molecular dynamics simulations demonstrates that the formation of a hierarchical MoO3/SnS2 core-shell heterostructure can effectively suppress the rapid dissociation of shell-layer SnS2 nanosheets via the interfacial coupling effect and the central MoO3 backbone can trap and support the polysulfide in the discharge/charge process. The results are responsible for the high storage capacity and rate capability of MoO3/SnS2 electrode materials. This work provides a novel design strategy for constructing high-performance electrodes for LIBs.

The capacity fading mechanism and improvement of cycling stability in MoS2-based anode materials for lithium-ion batteries.

Two-dimensional (2D) layered MoS2 nanosheets possess great potential as anode materials for lithium ion batteries (LIBs), but they still suffer from poor cycling performance. Improving the cycling stability of electrode materials depends on a deep understanding of their dynamic structural evolution and reaction kinetics in the lithiation process. Herein, thermodynamic phase diagrams and the lithiation dynamics of MoS2-based nanostructures with the intercalation of lithium ions are studied by using first-principles calculations and ab initio molecular dynamics simulations. Our results demonstrate that the continuous intercalation of Li ions induces structural destruction of 2H phase MoS2 nanosheets in the discharge process that follows a layer-by-layer dissociation mechanism. Meanwhile, the intercalation of Li ions leads to a structural transition of MoS2 nanosheets from the 2H to the 1T phase due to the ultralow transition barriers (∼0.1 eV). We find that the phase transition can slow down the dissociation of MoS2 nanosheets during lithiation. The result can be applied to explain extensive experimental observation of the fast capacity fading of MoS2-based anode materials between the first and the subsequent discharges. To suppress the dissociation of MoS2 nanosheets in the lithiation process, we propose a strategy by constructing a sandwich-like graphene/MoS2/graphene structure that indicates high chemical stability, superior conductivity, and high Li-ion mobility in the charge/discharge process, implying the possibility to induce an improvement in the anode cycling performance. This work opens a new route to rational design layered transition-metal disulfide (TMD) anode materials for LIBs with superior cycling stability and electrochemical performance.

Atomic Mechanism of Electrocatalytically Active Co-N Complexes in Graphene Basal Plane for Oxygen Reduction Reaction.

Superior catalytic activity and high chemical stability of inexpensive electrocatalysts for the oxygen reduction reaction (ORR) are crucial to the large-scale practical application of fuel cells. The nonprecious metal/N modified graphene electrocatalysts are regarded as one of potential candidates, and the further enhancement of their catalytic activity depends on improving active reaction sites at not only graphene edges but also its basal plane. Herein, the ORR mechanism and reaction pathways of Co-N co-doping onto the graphene basal plane have been studied by using first-principles calculations and ab initio molecular dynamics simulations. Compared to singly N-doped and Co-doped graphenes, the Co-N co-doped graphene surface exhibits superior ORR activity and the selectivity toward a four-electron reduction pathway. The result originates from catalytic sites of the graphene surface being modified by the hybridization between Co 3d states and N 2p states, resulting in the catalyst with a moderate binding ability to oxygenated intermediates. Hence, introducing the Co-N4 complex onto the graphene basal plane facilitates the activation of O2 dissociation and the desorption of H2O during the ORR, which is responsible for the electrocatalyst with a smaller ORR overpotential (∼1.0 eV) that is lower than that of Co-doped graphene by 0.93 eV. Our results suggest that the Co-N co-doped graphene is able to compete against platinum-based electrocatalysts, and the greater efficient electrocatalysts can be realized by carefully optimizing the coupling between transition metal and nonmetallic dopants in the graphene basal plane.