The dark gray corrosion layer (patina) formed on the surface of a polished low tin bronze alloy following exposure to a deoxygenated and saturated aqueous solutions of H2S has been characterized by X‐ray photoelectron spectroscopy, scanning electron microscopy‐energy dispersive spectroscopy and X‐ray diffraction. The system represents a model for bronze corrosion in reducing conditions where sulfate‐reducing bacteria in soils or deoxygenated seawater may generate H2S during respiration. The initial surface was dominated by metallic copper together with Sn, Pb and Zn oxides and hydroxides. Surface enrichment of Pb and Zn was noted because of a smearing effect during polishing. At least some of the lead was crystalline. In contrast, the corrosion layer formed by H2S(aq) exposure was dominated by polycrystalline Cu2S (low and high chalcocite) and smaller concentrations of CuSO4 · nH2O. This surface was enriched with Zn as Zn(OH)2. Lead was present as redeposited PbS (galena) crystallites in at least two different morphologies. Unlike bronzes exposed to oxidizing conditions, which develop protective SnO2 layers, the H2S(aq)‐exposed surface was considerably depleted in Sn. Copyright © 2014 John Wiley & Sons, Ltd.
Purpose To report a rare case of bilateral pulmonary emboli following pars plana vitrectomy with postoperative prone positioning. Observations A 60 year-old female presented with a fourmonth history of unilateral distorted vision. Ocular coherence tomography revealed a full thickness macular hole. Two weeks later, the patient underwent a 23-gauge pars plana vitrectomy with internal limiting membrane peeling and 12% perfluoropropane gas tamponade. Postoperatively, she completed two weeks of prone positioning. Five days later, she presented with a two day history of abdominal pain and shortness of breath. Computed tomography angiography revealed bilateral pulmonary emboli. The patient received six months of anticoagulation to prevent further thromboembolic events. Conclusions Life threatening blood clots can form due to prolonged immobilization from prone positioning. Patients should be educated to perform light exercise postoperatively to prevent complications of blood stasis.
Purpose To report a unique presentation of ciliochoroidal effusion syndrome with central serous-like chorioretinopathy and secondary angle closure following exogenous testosterone use. Observations A 37 year-old man presented with a two week history of blurred vision, elevated intraocular pressure, and myopic shift in his right eye. Gonioscopy showed angle closure. After YAG iridotomy, ultrasound biomicroscopy (UBM) showed ciliochoroidal effusion and anterior rotation of the ciliary processes. Subsequent color fundus photography, enhanced depth imaging optical coherence tomography (EDI-OCT) and near-infrared reduced-illuminance autofluorescence imaging (NIR-RAFI) showed macular striae, choroidal folds, and increased choroidal thickness without presence of subretinal fluid (SRF) or pigment epithelial detachment (PED). Further questioning revealed the patient was using dermal testosterone gel for six months for treatment of hypogonadism. The patient stopped using the testosterone gel, and his visual acuity and intraocular pressure significantly improved six weeks later. Follow-up UBM showed significant improvement of the ciliochoroidal effusion, and repeat multimodal images demonstrated resolution of the macular striae and choroidal folds, and slightly improved choroidal thickness. Conclusions and importance Our patient demonstrates a rare case of ciliochoroidal effusion, central serous-like chorioretinopathy, and secondary angle closure that dramatically improved with cessation of testosterone. We believe that this unique clinical constellation is the first to be reported associated with exogenous testosterone use.
Purpose: To describe two cases of catastrophic, bilateral retinal vascular occlusion after intravitreal (IVT) bevacizumab injection.Methods: Case series. Main outcome measures included clinical and fluorescein angiography findings.Results: Case 1-A 65-year-old woman with calcinosis, Raynaud phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasis syndrome developed acute, severe, bilateral visual loss 2 weeks after bilateral IVT bevacizumab injection for proliferative diabetic retinopathy. Examination and fluorescein angiography revealed moderate anterior chamber inflammation, bilateral perivascular retinal hemorrhages, and near total retinal vascular occlusion. Extensive testing revealed moderately elevated anti-B2 glycoprotein (antiphospholipid) antibodies. Case 2-An 85-year-old man with polymyalgia rheumatica and left eye exudative age-related macular degeneration experienced severe, bilateral, sequential visual loss in the left eye and then right eye approximately 3 weeks after IVT bevacizumab left eye injection. Examination revealed bilateral panuveitis, diffuse perivascular exudates, and intraretinal hemorrhages. Fluorescein angiography showed diffuse venous leakage. Extensive testing revealed an elevated antinuclear antibody and mildly elevated anticardiolipin antibody.Conclusion: Patients with underlying retinal vascular vulnerabilities may be at increased risk of catastrophic, bilateral retinal vascular occlusion after treatment with IVT bevacizumab. The moderate-to-severe intraocular inflammation in both cases and the contralateral involvement after unilateral IVT injection in Case 2 suggest a possible delayed immunemediated mechanism.
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