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Silicone Oil (silicone + oil)
Kinds of Silicone Oil Selected AbstractsHighly Purified 1000-cSt Silicone Oil for Treatment of Human Immunodeficiency Virus-Associated Facial Lipoatrophy: An Open Pilot TrialDERMATOLOGIC SURGERY, Issue 10 2004Derek H. Jones MD Background. Among human immunodeficiency virus-infected individuals, facial lipoatrophy has become epidemic. Those affected are stigmatized, leading to psychological distress, social and career impediments, and impaired compliance to human immunodeficiency virus medications. Temporary treatment options are limited by excessive cost, necessity of frequent treatments, and lack of a natural look or feel beneath the skin. Affected patients require more persistent, affordable, safe, and effective treatment options. Objective. The objective was to evaluate the safety and efficacy of highly purified 1000-cSt silicone oil injected by microdroplet serial puncture technique for the treatment of human immunodeficiency virus-associated lipoatrophy. Methods. Data on 77 patients with a complete correction were analyzed to determine the number of treatments, amount of silicone, and time required to reach complete correction, relative to initial severity. Results. The volume of silicone, number of treatments, and time required to reach a complete correction were directly related to initial severity of lipoatrophy (p < 0.0001). Supple, even facial contours were routinely restored, with all patients tolerating treatments well. No adverse events were noted. Conclusion. In this pilot trial, we have demonstrated that highly purified 1000-cSt silicone oil is a safe and effective treatment option for human immunodeficiency virus facial lipoatrophy. Longer-term safety and efficacy in human immunodeficiency virus patients remain to be proven. [source] Silicone oil: An effective absorbent for the removal of hydrophobic volatile organic compoundsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2010Guillaume Darracq Abstract BACKGROUND: Hydrophobic volatile organic compounds (VOCs), such as toluene, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), are poorly soluble in water and classical air treatment processes like chemical scrubbers are not efficient. An alternative technique involving an absorption step in an organic solvent followed by a biodegradation phase was proposed. The solvent must fulfil several characteristics, which are key factors of process efficiency, and a previous study allowed polydimethylsiloxane (or PDMS, i.e. silicone oil) to be selected for this purpose. The aim of this paper was to determine some of its characteristics like absorption capacity and velocity performances (Henry's constant, diffusivity and mass transfer coefficient), and to verify its non-biodegradability. RESULTS: For the three targeted VOCs, Henry's constants in silicone oil were very low compared to those in water, and solubility was infinite. Diffusivity values were found to be in the range 10,10 to 10,11 m2 s,1 and mass transfer coefficients did not show significant differences between the values in pure water and pure silicone oil, in the range 1.0 × 10,3 to 4.0 × 10,3 s,1 for all the VOCs considered. Silicone oil was also found to be non-biodegradable, since its biological oxygen demand (BOD5) value was zero. CONCLUSION: Absorption performances of silicone oil towards toluene, DMS and DMDS were determined and showed that this solvent could be used during the first step of the process. Moreover, its low biodegradability and its absence of toxicity justify its use as an absorbent phase for the integrated process being considered. Copyright © 2010 Society of Chemical Industry [source] Passage of a bubble through a liquid,liquid interfaceAICHE JOURNAL, Issue 3 2008N. Dietrich Abstract The aim of this study is to investigate the bubble passage at a liquid,liquid interface using a high-speed video camera (950 images per second) and a Particle Image Velocimetry (PIV) system. Experiments were conducted in a square Plexiglas column of 0.1 m. Bubbles were generated through a submerged orifice (D = 1 × 10,3 m). The Newtonian Emkarox (HV45) solution was employed for the heavy phase whereas two different organic liquids of different viscosity (Silicone oil 10 mPa s and 100 mPa s) were used as light phase. Experimental results show the effect of the bubble size and the viscosity of the light phase on the retention time, the length of the column of fluid entrained behind the bubble, the bubble velocity as well as the velocity fields at the liquid,liquid interface. © 2008 American Institute of Chemical Engineers AIChE J, 2008 [source] Highly Purified 1000-cSt Silicone Oil for Treatment of Human Immunodeficiency Virus-Associated Facial Lipoatrophy: An Open Pilot TrialDERMATOLOGIC SURGERY, Issue 10 2004Derek H. Jones MD Background. Among human immunodeficiency virus-infected individuals, facial lipoatrophy has become epidemic. Those affected are stigmatized, leading to psychological distress, social and career impediments, and impaired compliance to human immunodeficiency virus medications. Temporary treatment options are limited by excessive cost, necessity of frequent treatments, and lack of a natural look or feel beneath the skin. Affected patients require more persistent, affordable, safe, and effective treatment options. Objective. The objective was to evaluate the safety and efficacy of highly purified 1000-cSt silicone oil injected by microdroplet serial puncture technique for the treatment of human immunodeficiency virus-associated lipoatrophy. Methods. Data on 77 patients with a complete correction were analyzed to determine the number of treatments, amount of silicone, and time required to reach complete correction, relative to initial severity. Results. The volume of silicone, number of treatments, and time required to reach a complete correction were directly related to initial severity of lipoatrophy (p < 0.0001). Supple, even facial contours were routinely restored, with all patients tolerating treatments well. No adverse events were noted. Conclusion. In this pilot trial, we have demonstrated that highly purified 1000-cSt silicone oil is a safe and effective treatment option for human immunodeficiency virus facial lipoatrophy. Longer-term safety and efficacy in human immunodeficiency virus patients remain to be proven. [source] Injecting 1000 Centistoke Liquid Silicone With Ease and PrecisionDERMATOLOGIC SURGERY, Issue 3 2003Anthony V. Benedetto DO, FACP BACKGROUND Since the Food and Drug Administration approved the use of the 1000 centistoke liquid silicone, Silikon 1000, for intraocular injection, the off-label use of this injectable silicone oil as a permanent soft-tissue filler for facial rejuvenation has increased in the United States. Injecting liquid silicone by the microdroplet technique is the most important preventive measure that one can use to avoid the adverse sequelae of silicone migration and granuloma formation, especially when injecting silicone to improve small facial defects resulting from acne scars, surgical procedures, or photoaging. OBJECTIVE To introduce an easy method for injecting a viscous silicone oil by the microdroplet technique, using an inexpensive syringe and needle that currently is available from distributors of medical supplies in the United States. METHOD We suggest the use of a Becton Dickinson 3/10 cc insulin U-100 syringe to inject Silikon 1000. This syringe contains up to 0.3 mL of fluid, and its barrel is clearly marked with an easy-to-read scale of large cross-hatches. Each cross-hatch marking represents either a unit value of 0.01 mL or a half-unit value of 0.005 mL of fluid, which is the approximate volume preferred when injecting liquid silicone into facial defects. Because not enough negative pressure can be generated in this needle and syringe to draw up the viscous silicone oil, we describe a convenient and easy method for filling this 3/10 cc diabetic syringe with Silikon 1000. RESULTS We have found that by using the Becton Dickinson 3/10 cc insulin U-100 syringe, our technique of injecting minute amounts of Silikon 1000 is facilitated because each widely spaced cross-hatch on the side of the syringe barrel is easy to read and measures exact amounts of the silicone oil. These lines of the scale on the syringe barrel are so large and clearly marked that it is virtually impossible to overinject the most minute amount of silicone. CONCLUSION Sequential microdroplets of 0.01 cc or less of Silikon 1000 can be measured and injected with the greatest ease and precision so that inadvertent overdosing and complications can be avoided. [source] A pilot-scale demonstration of a membrane-based absorption- stripping process for removal and recovery of volatile organic compoundsENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2001S. Majumdar A new membrane-based continuous absorption-stripping process has been developed to separate gas/vapor mixtures, such as volatile organic compounds (VOCs), from a nitrogen/air stream. Two different hollow fiber membrane modules are needed in this process to remove the VOCs. In the first module, VOC-laden nitrogen/air stream flows through the bore of the hollow fibers. A suitable absorbent liquid with a high solubility for the VOC and essentially no solubility for nitrogen/air is pumped countercurrently over the outside of the fibers. This liquid is an inert, nontoxic, and essentially nonvolatile, organic solvent. The VOCs are effectively removed from nitrogen/air to a very low level and are concentrated in the absorbent for recovery, while the absorbent is regenerated by heating and subjecting it to vacuum in a separate hollow fiber membrane module called the stripping module. A pilot-scale membrane-based absorption-stripping unit was located next to a paint spray booth at Robins Air Force Base, Warner Robins, GA. Tests were performed on slip-streams of real-time air emissions from scheduled intermittent painting operations, so the concentration of VOC in the exhaust air fluctuated with time. The VOC removal efficiency was determined as a function of the feed air flow rate and the absorbent (silicone oil) flow rate. Depending on the gas/liquid flow rates and the inlet VOC concentration, the process successfully removed as much as 95+% of the VOC present. The experimental results have been compared with theoretical predictions. [source] Silicone oil: An effective absorbent for the removal of hydrophobic volatile organic compoundsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2010Guillaume Darracq Abstract BACKGROUND: Hydrophobic volatile organic compounds (VOCs), such as toluene, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), are poorly soluble in water and classical air treatment processes like chemical scrubbers are not efficient. An alternative technique involving an absorption step in an organic solvent followed by a biodegradation phase was proposed. The solvent must fulfil several characteristics, which are key factors of process efficiency, and a previous study allowed polydimethylsiloxane (or PDMS, i.e. silicone oil) to be selected for this purpose. The aim of this paper was to determine some of its characteristics like absorption capacity and velocity performances (Henry's constant, diffusivity and mass transfer coefficient), and to verify its non-biodegradability. RESULTS: For the three targeted VOCs, Henry's constants in silicone oil were very low compared to those in water, and solubility was infinite. Diffusivity values were found to be in the range 10,10 to 10,11 m2 s,1 and mass transfer coefficients did not show significant differences between the values in pure water and pure silicone oil, in the range 1.0 × 10,3 to 4.0 × 10,3 s,1 for all the VOCs considered. Silicone oil was also found to be non-biodegradable, since its biological oxygen demand (BOD5) value was zero. CONCLUSION: Absorption performances of silicone oil towards toluene, DMS and DMDS were determined and showed that this solvent could be used during the first step of the process. Moreover, its low biodegradability and its absence of toxicity justify its use as an absorbent phase for the integrated process being considered. Copyright © 2010 Society of Chemical Industry [source] Extractive bioconversion in a four-phase external-loop airlift bioreactorAICHE JOURNAL, Issue 7 2000Lidija Sajc The integration of biosynthesis and product separation can increase the productivity of immobilized plant cells in airlift bioreactors. Extractive bioconversion of anthraquinones was studied in an external-loop airlift bioreactor consisting of a riser, a downcomer, and two horizontal sections, while containing alginate-immobilized Frangula alnus cells, a continuous aqueous phase (nutrient solution), dispersed solvent phase (n-hexadecane or silicone oil), and gas bubbles. A simple mathematical model was developed to describe the cocurrent liquid-liquid extraction in the riser section of the bioreactor and to rationalize the measured product concentrations in the aqueous and solvent phase. The model equations were solved analytically in a dimensionless form and used to study the effects of flow conditions, solvent properties, product formation rate, droplet size, and contactor length on the extraction efficiency and product concentration profiles in the continuous and dispersed phase. [source] In Situ Cube-Corner Indentation of Soda,Lime Glass and Fused SilicaJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2004Dylan J. Morris Indentation fracture with a cube-corner diamond pyramid on soda,lime silicate glass and fused silica is investigated during the entire indentation cycle in both silicone oil and ambient-air environments. Radial cracks form immediately on loading in all cases. The two-component, elastic-contact + elastic-plastic mismatch (residual) stress field model that has been used successfully to describe radial crack evolution at Vickers indentations fails to describe the fracture response with the cube-corner. The amplitudes of both elastic-contact and residual stress-intensity factors as deduced from these cube-corner experiments are up to a factor of 10 greater than have been previously observed. [source] Synthesis of New Cellobiose-Based Glycopolysiloxanes and their Use as Polymer Stabilizers in Miniemulsion PolymerisationMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 17 2008Solenn Berson Abstract New glycopolysiloxanes were synthesized from cellobiose and commercially available reactive silicone oils or MD,M precursors. Their synthesis is based on the hydrosilylation of allyl-functionalized cellobiose onto the reactive silicone oil, after protection of the hydroxyl functions. The subsequent deprotection step leads to a redistribution of the silicon chain to yield oligomers with around 5 or 6 silicon atoms. Two water-dispersible glycosiloxanes were used for the steric stabilisation of vinyl acetate (VAc) miniemulsion polymerisation with up to 10% Miglyol® as the hydrophobic component. The best performances were obtained by using a mixture of non-ionic triblock copolymer and glycopolysiloxane. Poly(vinyl acetate) (PVAc) latex with particle sizes around 200 nm were obtained, displaying colloidal stabilisation upon long-time storage. [source] Dispersion-Polymerized Carbon Nanotube/Poly(methyl methacrylate) Composite Particles and their Electrorheological CharacteristicsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 5 2007Sung Tae Kim Abstract An in situ dispersion polymerization method was adopted to synthesize particulate composites of MWNTs and PMMA, mainly for the investigation of their electrorheological characteristics. The morphology of the PMMA microparticles synthesized in the presence of the MWNTs was examined by both SEM and TEM, showing that the MWNTs were not only grafted onto the surface of the PMMA microbeads, but were also embedded inside the synthesized microbeads. The synthesized MWNT/PMMA particulate composites were also characterized by zeta-potential measurements and TGA for electric and thermal stability studies, respectively. A suspension of the MWNT/PMMA microparticles dispersed in silicone oil was found to show enhanced electrorheological properties on the increase of shear stresses when subjected to an external electric field, exhibiting high yield stresses despite the tiny amount of the MWNT associated. [source] Langjährige Messung von Kraft- und Verformungsgrößen in Neotopf-Gleitlagern einer Spannbetonstraßenbrücke.BETON- UND STAHLBETONBAU, Issue 12 2006Brückenlager-Monitoring Zwei Lager der dreifeldrigen Spannbeton-Straßenbrücke über den Aasee in Münster wurden beim Bau in den Jahren 1987/88 als Neotopf-Gleitlager mit Meßeinrichtungen ausgestattet, die den Gleitspalt und den Kippspalt messen. Außerdem ist eine Druckmeßdose eingebaut worden, die den Druck des Silikonöls im Stahltopf unter dem Elastomer mißt. Mit diesen Meßeinrichtungen wurde die Lastgeschichte der Lager während der Bauzeit festgestellt. Im Laufe der 18jährigen Standzeit der Brücke wurden die Lager mit diesen Meßeinrichtungen überwacht. Nach der Fertigstellung der Brücke und in Abständen von einigen Jahren sind Zustandgrößen der Lager im Sinne eines Monitoring auch durch Überfahren der Brücke mit Lastkraftwagen gemessen worden. Die Lager weisen nach 18 Jahren nur geringfügige Abnutzung auf. Longterm Measuring of Forces and Displacements in Elastomer Pot Sliding Bearings of a Prestressed Concrete Road Bridge. Monitoring of Bridge Bearings Two bearings of a three span prestressed concrete road bridge over the lake Aa in the City of Münster were equipped with elastomer pot sliding bearings with measuring devices during the erection in 1987/88, that are able to measure the distance between sliding slab and covering slab and the rotation of the covering slab. Moreover there are dynamometers, which measure the compression stress of the silicone oil in the pot under the elastomer. With these measuring devices the load history of the bearings during the time of erection of the bridge was monitored. In the 18 years that the bridge is in operation, the bearings have been monitored with these measuring devices. Following the completion of the bridge and further in intervals of some years the loads and displacements of the bearings were monitored especially during lorries were crossing the bridge. The bearings show only minimal attrition after 18 years in use. [source] Improved reactor performance and operability in the biotransformation of carveol to carvone using a solid,liquid two-phase partitioning bioreactorBIOTECHNOLOGY & BIOENGINEERING, Issue 5 2008Jenna L.E. Morrish Abstract In an effort to improve reactor performance and process operability, the microbial biotransformation of (,)- trans -carveol to (R)-(,)-carvone by hydrophobic Rhodococcus erythropolis DCL14 was carried out in a two phase partitioning bioreactor (TPPB) with solid polymer beads acting as the partitioning phase. Previous work had demonstrated that the substrate and product become inhibitory to the organism at elevated aqueous concentrations and the use of an immiscible second phase in the bioreactor was intended to provide a reservoir for substrates to be delivered to the aqueous phase based on the metabolic rate of the cells, while also acting as a sink to uptake the product as it is produced. The biotransformation was previously undertaken in a two liquid phase TPPB with 1-dodecene and with silicone oil as the immiscible second phase and, although improvement in the reactor performance was obtained relative to a single phase system, the hydrophobic nature of the organism caused the formation of severe emulsions leading to significant operational challenges. In the present work, eight types of polymer beads were screened for their suitability for use in a solid,liquid TPPB for this biotransformation. The use of selected solid polymer beads as the second phase completely prevented emulsion formation and therefore improved overall operability of the reactor. Three modes of solid,liquid TPPB operation were considered: the use of a single polymer bead type (styrene/butadiene copolymer) in the reactor, the use of a mixture of polymer beads in the reactor (styrene/butadiene copolymer plus Hytrel® 8206), and the use of one type of polymer beads in the reactor (styrene/butadiene copolymer), and another bead type (Hytrel® 8206) in an external column through which fermentation medium was recirculated. This last configuration achieved the best reactor performance with 7 times more substrate being added throughout the biotransformation relative to a single aqueous phase benchmark reactor and 2.7 times more substrate being added relative to the best two liquid TPPB case. Carvone was quantitatively recovered from the polymer beads via single stage extraction into methanol, allowing for bead re-use. Biotechnol. Bioeng. © 2008 Wiley Periodicals, Inc. [source] The Mixing Efficiency of an Eccentric-Disc Kneading Zone in Intermeshing Co- and Counter-Rotating Twin-Screw ExtrudersCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 3 2004H. Brod Abstract The distributive mixing efficiency of a twin-screw extruder kneading zone consisting of eccentric disc elements was measured using an online video technique. Both co- and counter-rotation were examined. Viscous Newtonian silicone oil was used as model liquid and black iron oxide pigment served as tracer substance. Under isoviscous, creeping flow and non-diffusive conditions and for a fixed flow rate ratio of the colored and uncolored feed streams, the intensity of segregation S is only a function of the kinematic parameter , (the ratio of the imposed extruder throughput and the throughput at zero axial pressure gradient). The measured dependency of S on , is in qualitative agreement with the results of Pawlowski for a single screw extruder. The data was also plotted against the dimensionless speed of rotation, i.e. the product of the screw speed and the average residence time within the mixing section. This brings the abscissa ranges for mixers with different conveying capacity closer together, and differences in mixing efficiency between the tested configurations can be better interpreted. The energetic efficiency of the mixers investigated is compared by applying the concept of specific action. This helps to decide which mixer geometry and operating conditions produce a given homogeneity with the lowest amount of work done by viscous forces. [source] 3315: Transconjunctival sutureless 20GACTA OPHTHALMOLOGICA, Issue 2010CJ POURNARAS Purpose To evaluate a trocar system that allows the use of the regular 20-gauge vitrectomy instruments for a transconjunctival sutureless surgery for the treatment of various surgically treated vitreo-retinal pathologies. Methods The 20-gauge trocar system uses a 10° self-sealing tunneled incision made with trocars introduced with a inserter blade of 0.9 mm diameter. Incisions are radially made at 3.5 mm from the limbus and tunnels are made limbus-parallel. Evaluation of the surgical procedure, sclerotomies closure by OCT, anatomical and visual outcomes in various vitreoretinal pathologies treated in current vitreoretinal practice. Results Postoperative patient comfort and less eye inflammation are provided by the sutureless technique, allthough small conjunctival hemorrhage caused by the grasping forceps used to hold the eye during the insertion of the trocars may occur. The 20-gauge trocar system using 10° self-sealing tunneled incision remains very stable in the eye even during peripheral vitrectomy with indentation and they also decrease the surgical induced trauma at the entry sites. The use of nonflexible instruments, the same as in 20-gauge conventional vitrectomy, provides easy access to the entire periphery.thus the system can be used in almost all vitreoretinal surgeries. It allows the use of phragmatome and is easy to work even with 5,000 centistokes silicone oil. Conclusion In the era of sutureless surgeries, the 20-gauge trocar system is a safe, comfortable, convinient with current instrumentation and less expensive alternative to 25- and 23-gauge vitrectomy. [source] Use of heavy silicone oil (Densiron-68®) in the treatment of persistent macular holesACTA OPHTHALMOLOGICA, Issue 8 2009Alexandra Lappas Abstract. Purpose:, In this retrospective case series, we studied the effect of ,heavy' silicone oil on persisting macular holes. Patients with macular holes that failed to close after conventional macular hole surgery were retreated with the longterm internal tamponade Densiron-68®. Methods:, Twelve patients with primary macular holes that persisted after pars plana vitrectomy, peeling of the internal limiting membrane and internal gas tamponade with SF6 (sulphur hexafluoride) were retreated with heavy silicone oil, Densiron-68®, in the University Eye Hospital, Cologne. After 1.5,4 months the Densiron-68® was removed. Best corrected visual acuity (VA), slit-lamp examination, binocular fundus examination and optical coherence tomography (OCT) were used for evaluation pre- and postoperatively. The follow-up period was 3,7 months. Results:, Preoperatively, all patients displayed full-thickness macular holes, with a mean size of 502.25 ,m (± 129.39 ,m). Postoperatively, 11 of 12 macular holes were closed. One patient experienced a reopening of the macular hole. Mean VA was 20/250 (1.07 ± 0.22 logMAR) prior to treatment with Densiron-68® and 20/160 (0.84 ± 0.24 logMAR) postoperatively. Visual acuity increased from baseline in nine patients and decreased in one. Conclusions:, Retreatment of persisting macular holes with the heavy, longterm tamponade Densiron-68® resulted in anatomical closure of the hole in 11 of 12 cases. This result was accompanied by a functional improvement in VA in nine of 12 patients. [source] In vitro antimicrobial effect of vitreous endotamponading substancesACTA OPHTHALMOLOGICA, Issue 2009JA MONTERO MORENO Purpose To demonstrate the in vitro bactericidal, bacteriostatic or inert role of endotamponading substances. Methods Clinical isolates of Staphylococcus epidermidis, Staphylococcus aureus and Clostridium sp were cultured on blood agar plates in sulphur hexafluoride (SF6)and perfluoropropane (C3F8)atmospheres and under silicone oil (SO) and liquid perfluorocarbon (LPFC). The same germs were cultured under aerobic and anaerobic atmospheres as controls. Results SO, SF6 and C3F8 did not significantly inhibit the growth of anaerobic bacteria but markedly reduced the growth of aerobic germs, as compared with aerobic conditions. The growth of the bacteria under SO and SF6 and C3F8 was very similar to that observed under anaerobic conditions. LPFC did not affect the growth of aerobic or anaerobic bacteria. Conclusion Endotamponading gases and liquids seem to improve the visual and anatomical outcome of infected eyes and may limit the proliferation of aerobic germs in vitro. It is not known to what extent the antimicrobial effect of these substances would appear in vivo since oxygen diffusion from the blood could allow the growth of aerobic germs. [source] Heavy silicone oil versus standard silicone oil as vitreous tamponade in inferior PVR (HSO Study): design issues and implicationsACTA OPHTHALMOLOGICA, Issue 6 2007Antonia M. Joussen Abstract. Purpose:, Proliferative vitreoretinopathy (PVR) is the most important reason for blindness following retinal detachment. Presently, vitreous tamponades such as gas or silicone oil cannot contact the lower part of the retina. A heavier-than-water tamponade displaces the inflammatory and PVR-stimulating environment from the inferior area of the retina. The Heavy Silicone Oil versus Standard Silicone Oil Study (HSO Study) is designed to answer the question of whether a heavier-than-water tamponade improves the prognosis of eyes with PVR of the lower retina. Methods:, The HSO Study is a multicentre, randomized, prospective controlled clinical trial comparing two endotamponades within a two-arm parallel group design. Patients with inferiorly and posteriorly located PVR are randomized to either heavy silicone oil or standard silicone oil as a tamponading agent. Three hundred and fifty consecutive patients are recruited per group. After intraoperative re-attachment, patients are randomized to either standard silicone oil (1000 cSt or 5000 cSt) or Densiron® as a tamponading agent. The main endpoint criteria are complete retinal attachment at 12 months and change of visual acuity (VA) 12 months postoperatively compared with the preoperative VA. Secondary endpoints include complete retinal attachment before endotamponade removal, quality of life analysis and the number of retina affecting re-operation within 1 year of follow-up. Results:, The design and early recruitment phase of the study are described. Conclusions:, The results of this study will uncover whether or not heavy silicone oil improves the prognosis of eyes with PVR. [source] Effect of topical steroids on corneal epithelial healing after vitreoretinal surgeryACTA OPHTHALMOLOGICA, Issue 3 2006Fatma Yülek Abstract. Purpose:,Topical steroid use is usually avoided in cases of corneal epithelial defect. We evaluated the effect of topical steroid treatment on corneal epithelial healing after epithelial debridement in vitreoretinal surgery. Methods:,Our study population included 85 eyes undergoing vitreoretinal surgeries in our clinic. We prospectively compared the duration of corneal epithelial wound healing in 43 eyes in which topical dexamethasone was used with that in 42 eyes in which topical dexamethasone was not used in the early postoperative period after epithelial debridement. Factors that may retard corneal epithelial healing, including pre- and intraoperative topical solutions, median operative time, the presence of diabetes mellitus, prior ocular surgeries, pseudophakia, aphakia and the presence of intraocular gas or silicone oil in aphakic patients, were not significantly different between the two groups. Results:,The mean corneal epithelial defect closure time was 59.7 ± 2.6 hours (mean ± SEM) in the group receiving topical steroid treatment, and 61.9 ± 2.6 hours in the group that did not receive steroids. Conclusion:,Topical dexamethasone administered five times/day did not significantly retard corneal epithelial healing in subjects undergoing vitreoretinal surgery with postoperative topical steroid treatment, compared with subjects who did not receive steroid treatment. [source] Densiron intraocular tamponade: a case seriesCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 3 2008Beng Liam Lim MBBS(Hons) MPH Abstract Purpose:, To report on the use of Densiron (heavy silicone oil), a new endotamponade agent with proposed benefits in complex retinal detachments involving inferior proliferative vitreoretinopathy. Method:, Retrospective case note review. Results:, Ten cases (10 eyes) in which Densiron was used in eyes which had failed initial retinal detachment surgery. The overall success rate of long-term total reattachment was 70%. Mean preoperative visual acuity was logMAR 2.03 (SD 0.406), which improved to a mean postoperative visual acuity of logMAR 1.00 (SD 0.571) (P = 0.001). Conclusion:, Densiron was well tolerated with few side-effects and appears to be a useful agent in patients with inferior proliferative vitreoretinopathy. [source] Suicide-related perforating injury of globe with nail gunCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 3 2005Marc Rofail MB BS Abstract A case is reported of nail gun injury due to suicide attempt involvingboth orbits, frontal lobe and abdomen, which resulted in an unusualposterior perforation of the left globe. Injury was inflicted witha total of eight nails. Three nails entered the left orbit, oneof which perforated the posterior aspect of the left globe. Onenail entered the right orbit involving the optic nerve and crossedthe midline to finish in the left sphenoid sinus. Three nails enteredthe frontal lobe near the midline and the final nail pierced theleft lobe of the liver. The left eye underwent primary repair, lensectomyand vitrectomy with silicone oil and achieved a visual acuity of 6/60,3 months post removal of oil with sutured posterior chamberintraocular lens. The right eye suffered traumatic optic neuropathyand currently has a visual acuity of 6/36 due to senilecataract formation. No other serious sequelae resulted from theother injuries and the patient has recovered from his episode ofdepression. [source] Synthesis of New Cellobiose-Based Glycopolysiloxanes and their Use as Polymer Stabilizers in Miniemulsion PolymerisationMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 17 2008Solenn Berson Abstract New glycopolysiloxanes were synthesized from cellobiose and commercially available reactive silicone oils or MD,M precursors. Their synthesis is based on the hydrosilylation of allyl-functionalized cellobiose onto the reactive silicone oil, after protection of the hydroxyl functions. The subsequent deprotection step leads to a redistribution of the silicon chain to yield oligomers with around 5 or 6 silicon atoms. Two water-dispersible glycosiloxanes were used for the steric stabilisation of vinyl acetate (VAc) miniemulsion polymerisation with up to 10% Miglyol® as the hydrophobic component. The best performances were obtained by using a mixture of non-ionic triblock copolymer and glycopolysiloxane. Poly(vinyl acetate) (PVAc) latex with particle sizes around 200 nm were obtained, displaying colloidal stabilisation upon long-time storage. [source] | |||||||||||||||||||