ABSTRACT
The authors report a case of nonconforming focal choroidal excavation (FCE) identified in an eye following blunt, nonperforating trauma to the globe. Multimodal imaging was undertaken including color fundus photographs, enhanced depth imaging optical coherence tomography, fluorescein angiography, and fundus autofluorescence. This shows that FCE may result from blunt ocular trauma. The authors hypothesize that loss of structural support provided by an intact Bruch's membrane may be a key factor in precipitating the specific morphological changes associated with FCE occurring in a range of clinical settings. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:187-190.].
Subject(s)
Choroid Diseases/etiology , Eye Injuries/complications , Adult , Humans , Male , Vision Disorders/etiologyABSTRACT
PURPOSE: To report a giant retinal pigment epithelium rip in a patient with a bullous retinal and choroidal detachment. METHODS: Case report with widefield imaging, fundus autofluorescence, and optical coherence tomography of the retina. RESULTS: This 62-year-old patient had a history of advanced glaucoma, trabeculectomy, blebitis, and endophthalmitis. He had cataract surgery 6 weeks before presentation. He was found to have a large bullous retinal and choroidal detachment with a large retinal pigment epithelium tear at the limit of the choroidal detachment. After vitrectomy for retinal detachment repair, the tear was observed to extend inferiorly at the margins of the choroidal detachment. CONCLUSION: This case report demonstrates that large retinal pigment epithelium rips can be found associated with large bullous choroidal and retinal detachments. These tears seem similar to tears that have been observed after trabeculectomy.
Subject(s)
Choroid Diseases/complications , Retinal Detachment/complications , Retinal Perforations/etiology , Humans , Male , Middle AgedABSTRACT
PURPOSE: To report a giant retinal pigment epithelium rip in a patient with a bullous retinal and choroidal detachment. METHODS: Case report with widefield imaging, fundus autofluorescence, and optical coherence tomography of the retina. RESULTS: This 62-year-old patient had a history of advanced glaucoma, trabeculectomy, blebitis, and endophthalmitis. He had cataract surgery 6 weeks before presentation. He was found to have a large bullous retinal and choroidal detachment with a large retinal pigment epithelium tear at the limit of the choroidal detachment. After vitrectomy for retinal detachment repair, the tear was observed to extend inferiorly at the margins of the choroidal detachment. CONCLUSION: This case report demonstrates that large retinal pigment epithelium rips can be found associated with large bullous choroidal and retinal detachments. These tears seem similar to tears that have been observed after trabeculectomy.
ABSTRACT
Choroidal neovascularization (CNV) due to age-related macular degeneration (AMD) is an important cause of visual morbidity globally. Modern treatment strategies for neovascular AMD achieve regression of CNV by suppressing the activity of key growth factors that mediate angiogenesis. Vascular endothelial growth factor (VEGF) has been the major target of neovascular AMD therapy for almost two decades, and there have been several intravitreally-administered agents that have enabled anatomical restitution and improvement in visual function with continual dosing. Aflibercept (EYLEA(®)), initially named VEGF Trap-eye, is the most recent anti-VEGF agent to be granted US Food and Drug Administration approval for the treatment of neovascular AMD. Biologic advantages of aflibercept include its greater binding affinity for VEGF, a longer intravitreal half-life relative to other anti-VEGF agents, and the capacity to antagonize growth factors other than VEGF. This paper provides an up-to-date summary of the molecular mechanisms mediating CNV. The structural, pharmacodynamic, and pharmacokinetic advantages of aflibercept are also reviewed to rationalize the utility of this agent for treating CNV. Results of landmark clinical investigations, including VIEW 1 and 2 trials, and other important studies are then summarized and used to illustrate the efficacy of aflibercept for managing treatment-naïve CNV, recalcitrant CNV, and CNV due to polypoidal choroidal vasculopathy. Safety profile, patient tolerability, and quality of life measures related to aflibercept are also provided. The evidence provided in this paper suggests aflibercept to be a promising agent that can be used to reduce the treatment burden of neovascular AMD.
ABSTRACT
Liquid crystal containing composite fibres were produced via coaxial electrospinning, demonstrating that this technique can be used for producing new functional fibres and/or to study the impact of extreme confinement on liquid crystal phases.
Subject(s)
Liquid Crystals/chemistry , Povidone/chemistry , Titanium/chemistry , Electrochemistry , Particle Size , Surface Properties , TemperatureABSTRACT
Electrospinning of a polyelectrolyte and vapor deposition polymerization were combined to fabricate nanotubes of oxidatively stabilized poly(acrylonitrile) (PANDelta) with an outer diameter of 100 nm, a wall thickness of 14 nm, and centimeter-scale length. Poly(styrene sulfonate) sodium (PSSNa) nanofibers serves as sacrificial cores while vapor deposition polymerization was used to form smooth PAN sheaths of even thickness. After the PAN sheaths had been oxidatively stabilized, the PSSNa cores were etched away with water to form nanotubes of PANDelta. High-temperature carbonization of these nanotubes at 900 degrees C under Ar flow yielded carbon nanotubes with an outer diameter of 80 nm and wall thickness of 10 nm. Raman spectroscopy confirms that the carbon nanotubes were composed of highly disordered graphene sheets, consistent with the carbonization of PAN under similar conditions. These carbon nanotubes have many promising applications as catalyst supports, gas absorbents, and as encapsulants for controlled release of active compounds.
Subject(s)
Crystallization/methods , Electrochemistry/methods , Electrolytes/chemistry , Nanotechnology/methods , Nanotubes, Carbon/chemistry , Nanotubes, Carbon/ultrastructure , Polymers/chemistry , Gases/chemistry , Macromolecular Substances/chemistry , Materials Testing , Molecular Conformation , Particle Size , Rotation , Surface PropertiesABSTRACT
We have developed a method based on melt coaxial electrospinning for fabricating phase change nanofibers consisting of long-chain hydrocarbon cores and composite sheaths. This method combines melt electrospinning with a coaxial spinneret and allows for nonpolar solids such as paraffins to be electrospun and encapsulated in one step. Shape-stabilized, phase change nanofibers have many potential applications as they are able to absorb, hold, and release large amounts of thermal energy over a certain temperature range by taking advantage of the large heat of fusion of long-chain hydrocarbons. We have focused on compounds with melting points near room temperature (octadecane) and body temperature (eicosane) as these temperature ranges are most valuable in practice. We have produced thermally stable, phase change materials up to 45 wt % octadecane, as measured by differential scanning calorimetry. In addition, the resultant fibers display novel segmented morphologies for the cores due to the rapid solidification of the hydrocarbons driven by evaporative cooling of the carrier solution. Aside from the fabrication of phase change nanofibers, the melt coaxial method is promising for applications related to microencapsulation and controlled release of drugs.
ABSTRACT
Electrospinning provides a simple approach to fabricating nanofibers and assemblies with controllable hierarchical structures. In this communication, we demonstrate that electrospinning can be combined with calcination to further maneuver the morphology and phase structure of nanofibers. More specifically, single-crystal V2O5 nanorods could be grown on rutile nanofibers by carefully calcining composite nanofibers consisting of amorphous V2O5, amorphous TiO2, and poly(vinylpyrrolidone). The size of the resulting V2O5 nanorods could be conveniently controlled by varying the composition of the nanofibers and/or the calcination temperature. In addition to the nanorod-on-nanofiber hierarchical structure, we believe this approach can also be extended to fabricate other more complex architectures.
Subject(s)
Crystallization/methods , Electrochemistry/methods , Nanostructures/chemistry , Nanostructures/ultrastructure , Nanotechnology/methods , Titanium/chemistry , Vanadium Compounds/chemistry , Desiccation , Hot Temperature , Molecular Conformation , Particle Size , RotationABSTRACT
Highly porous fibers of various polymers were created by electrospinning with a modified collector. A bath of liquid nitrogen was used to freeze the fibers, inducing a phase separation between the polymer and the solvent. When the solvent was removed in vacuo, highly porous fibers were obtained. Poly(styrene), poly(acrylonitrile), poly(vinylidene fluoride), and poly(epsilon-caprolactone) were all electrospun into porous fibers using this simple method. These porous fibers have a range of potential applications in encapsulation, controlled release, superhydrophobic coating, and lightweight reinforcement.
ABSTRACT
Electrospinning is a simple, versatile, and useful technique for fabricating nanofibers from a rich variety of functional materials. The nanofibers are usually collected as nonwoven mats, in which the fibers are randomly oriented. We have recently demonstrated that the nanofibers can be uniaxially aligned by introducing an insulating gap into the conductive collector. To elucidate the mechanism of alignment, we have systematically studied the effect of the area and geometric shape of the insulating gap on the deposition of fibers. By modeling the electrostatic forces acting on the fiber, it was established that the fibers tended to be oriented along a direction such that the net torque of electrostatic forces applied to the two ends of a discrete segment of the fiber were minimized. By varying the design of electrode pattern, it was possible to control both alignment and assembly of the electrospun nanofibers.