Search results for "silicone"

Granulomatous reactions from silicone: a diagnostic trap for the dermatophalogist.

2011

Microfabrication of hybrid fluid membrane for microengines

2015

International audience; This paper describes the microfabrication and dynamic characterization of thick membranes providing a technological solution for microengines. The studied membranes are called hybrid fluid-membrane (HFM) and consist of two thin membranes that encapsulate an incompressible fluid. This work details the microelectromechanical system (MEMS) scalable fabrication and characterization of HFMs. The membranes are composite structures based on Silicon spiral springs embedded in a polymer (RTV silicone). The anodic bonding of multiple stacks of Si/glass structures, the fluid filling and the sealing have been demonstrated. Various HFMs were successfully fabricated and their dyna…

Solvent for removing silicone oil from intraocular lenses: experimental study comparing various biomaterials.

2000

Abstract Purpose To evaluate the effectiveness of a perfluorocarbon—perfluorohexyloctane (PFHO)—in removing silicone oil from different intraocular lenses (IOLs) and determine whether any removal technique enhances the removal of silicone oil. Methods Six IOL materials were analyzed: standard poly(methyl methacrylate) (PMMA), heparin-surface-modified (HSM) PMMA, AcrySof, 2 polyHEMAs with different water contents, and a second-generation SLM-2 silicone. One or 2 μL of a highly viscous silicone oil (5700 cs) was applied to the center of each IOL optic. Perfluorohexyloctane (2 mL) was then used to remove the silicone oil by 1 of 3 techniques: immersion of the IOL in PFHO; irrigation of the sil…

Development of a long-lasting ventricular catheter impregnated with a combination of antibiotics.

2003

A ventricular silicone catheter impregnated with a combination of rifampin and a quinolone was developed in order to prevent ventricular shunt related infections. As model substance for the quinolones we used sparfloxacin, because of its specific physicochemical properties resulting in a quantitative detection also in the presence of a second antibiotic. In our study we focused especially on an optimization of the antibiotic release out of the impregnated catheters in order to develop long lasting devices with a broad antimicrobial spectrum. A release-optimized catheter was tested with an in vitro colonization test and additionally with a method developed to examine the spread of bacteria o…

Improved method for cannula fixation for long-term intracerebral brain infusion

2017

Abstract Background Implanted osmotic minipumps are commonly used for long-term, brain-targeted delivery of a wide range of experimental agents by being connected to a catheter and a cannula. During the stereotactical surgery procedure, the cannula has to be placed correctly in the x-y directions and also with respect to the injection point in the z-direction (deepness). However, the flat fixation base of available cannula holders doesn’t allow an easy, secure fixation onto the curve-shaped skull. New method We have developed a modified method for a better fixation of the cannula holder by using an easy-to-produce, skull-shaped silicone spacer as fixation adapter. Results We describe the ap…

Silicone-Silver Penile Prosthesis: Description, Operative Approach and Results

1980

A silicone penile prosthesis in which silver wires are embedded to allow for voluntary bending of the penis for urination and resting position and for straightening for intercourse is described. The implantation is done via a hemicircular incision on the dorsum of the penis in the sulcus coronarius. Buck's fascia is identified and opened, and the corpora are dilated up to 30F. After the exact length is determined with a special sizer the prosthesis is slipped into each corpus cavernosum. The advantage of this approach is the optimal insertion of the prosthesis distal to the sulcus coronarius, thereby preventing kinking of the glans during intercourse. Our experiences with the implantation i…

TREATMENT OF PERSISTENTLY OPEN MACULAR HOLES WITH HEAVY SILICONE OIL (DENSIRON 68) VERSUS C2F6. A PROSPECTIVE RANDOMIZED STUDY

2016

Abstract PURPOSE: To compare the efficacy of a mixture of silicone oil and perfluorohexyloctane (Densiron 68) with C2F6 gas endotamponade in the retreatment of persistently open full-thickness macular holes. METHODS: In this prospective randomized study, 21 consecutive patients who were unsuccessfully operated on for large idiopathic full-thickness macular hole were randomly assigned to undergo a second vitrectomy with 20% perfluoroethane gas (C2F6, Group A) or with Densiron 68 tamponade (Group B). PRIMARY OUTCOMES: Endpoint (12 months) full-thickness macular hole closure rate by spectral domain optical coherence tomography and logMAR corrected distance visual acuity. SECONDARY OUTCOMES: po…

Heavy versus standard silicone oil in the management of retinal detachment with macular hole in myopic eyes

2011

PURPOSE: The purpose of this study was to compare pars plana vitrectomy (PPV) with 1000 cSt silicone oil endotamponade and PPV with densiron endotamponade for retinal detachment with macular hole and posterior staphyloma in highly myopic eyes. PATIENTS AND METHODS: In a prospective study, 30 eyes of 30 patients were randomly assigned to PPV and densiron (n = 15) or PPV with silicone oil (n = 15). All eyes had laser photocoagulation of the macular hole rim after PPV. Silicone oil or densiron was removed 12 weeks after surgery. Patients were followed-up for 6 months after oil removal. RESULTS: In the densiron group, the retinal reattachment rate was 100% with densiron in situ and 87% after it…

A New Model of Skull Base Reconstruction following Expanded Endonasal or Transoral Approaches – Long-Term Results in Primates

2007

<i>Objective:</i> The direct endonasal or transoral transclival approaches to the skull base permit effective minimally invasive surgery along the clivus region. Developing consistently effective techniques to prevent cerebrospinal fluid (CSF) leaks and their consequences (infections and healing processes with long and complicated recoveries) remains a major challenge. In this study, we tested over a long period a method of bone reconstruction newly developed by us, which makes use of a specially designed elastic silicone plug that can be employed for bone replacement after minimally invasive skull base surgery without risk of postoperative CSF leaks. After acute testing of plug…

Effect of head position on refraction in aphakic and phakic silicone-filled eyes.

1997

BACKGROUND The refraction of the eye is altered significantly after the instillation of silicone oil into the vitreous cavity because of the silicone oil's high refractive index. The degree of the refractive change shows diurnal variation and depends on the patient's head position. PATIENTS AND METHODS To analyze the degree and time course of refractive changes with respect to head position, the authors performed objective refraction in five aphakic and five phakic silicone oil-instilled eyes with attached maculae using an automatic hand-held refractometer. In each patient, 25 measurements were taken at short intervals using a hand-held autorefractometer with the patient in different positi…