Hydrofluoric Acid and Other Impurities in Toxic Perfluorooctane Batches.

Purpose: The complications with cytotoxic perfluorooctane (PFO) batches reported in 2015 were attributed to reactive underfluorinated impurities whose chemical identity and behavior still need to be clarified.

Material And Methods: We analyzed original packaged samples of Alaocta batches involved in several reported cases of retinal toxicity. (A) The impurity profile was determined.

How to Ward Off Retinal Toxicity of Perfluorooctane and Other Perfluorocarbon Liquids?

Purpose: Reactive and underfluorinated impurities are acknowledged as a source of cytotoxicity of perfluorocarbon liquids (PFCLs) used as blood substitutes. To determine whether this is also a relevant factor in retinal toxicity, we analyzed eight PFO batches associated with adverse ocular events.

Methods: (A) The amount of reactive and underflurinated impurities was analyzed by fluoride-selective potentiometry and expressed as H-value.

[Retinal damage by perfluorocarbon liquids - a question of specific gravity? Intraocular pressure peaks and shearing forces].

Background: Perfluorocarbon liquids (PFCL) cause retinal damage when used as long-term ocular endotamponades. Whether these changes are related to the mechanical or to the chemical properties of PFCL is unclear. The purpose of this study was to evaluate pressure spikes or shearing forces during endotamponade with PFCL and standardised eye movements.

An epidemic of sticky silicone oil at the Rotterdam Eye Hospital. Patient review and chemical analyses.

Purpose: To report and study the phenomenon of abnormal silicone oil adherent to the retina at the time of removal in a number of patients.

Materials And Methods: Chart review was performed to identify possible patient or procedural factors that could predispose to sticky silicone oil formation. Gas chromatography-mass spectroscopy and nuclear magnetic resonance spectroscopy analyses were performed on sticky silicone oil samples, on perfluorocarbon liquid and on silicone oil samples straight from the vial.

The phenomenon of "sticky" silicone oil.

Background: To investigate the reasons for difficulties removing silicone oil from the vitreous cavity due to putative adherence to the retina.

Methods: Gas chromatography-coupled mass spectroscopy of the headspace (GC/MS/HS) and gel permeation chromatography (GPC) were used to detect volatile compounds in silicone oil samples explanted from patients, qualitatively as well as quantitatively. Surface and interfacial tensions of the explanted samples were measured using the pendent-drop technique.

Influence of a new surface modification of intraocular lenses with fluoroalkylsilan on the adherence of endophthalmitis-causing bacteria in vitro.

Introduction: Dynasilan is a fluoroalkylsilan that is able to interact with surface active centres on intraocular lenses (IOL), offering a new way for surface modification of different IOL materials. The purpose of this in vitro study was to investigate the influence of this new surface modification on the adherence of two typical endophthalmitis causing bacteria (Staphylococcus epidermidis, Propionibacterium acnes).

Materials And Methods: In a pilot experiment, the effect of Dynasilan coating on the adherence of S.

Interaction of different ocular endotamponades as a risk factor for silicone oil emulsification.

Purpose: To investigate the influence of other substances used intraoperatively in vitreoretinal surgery on the emulsification of silicone oil in patients' eyes.

Methods: Gas chromatography coupled mass spectroscopy of the headspace (GC/MS/HS) was used to detect volatile compounds in silicone oil samples explanted from patients qualitatively as well as quantitatively. Surface and interfacial tensions of the explanted samples were measured using the pendent drop technique.

Preparation and processing of vitreoretinal instrumentation and equipment as a risk factor for silicone oil emulsification.

Purpose: To investigate possible sources for the induction of silicone oil emulsification in patients' eyes.

Methods: The contaminants on a ready-to-use standard set of vitreoretinal instruments cleaned and sterilized in an eye clinic were determined. The determination of detergents was carried out according to a standardized procedure, which uses ultrapurified water to rinse the equipment in question, followed by a measurement of the conductivity.

[The influence of a new surface treatment of silicone intracoular lenses with fluoralkylsitan on the adherence of endophthalmitic bacteria in vitro]].

Introduction: Dynasilan is a fluoroalkylsilan which is able to bind to surface active molecules of intraocular lenses (IOLs), thereby offering a new option for surface modification of silicone lenses. The purpose of this in vitro study was to investigate the influence of this new surface treatment on the adherence of two typical endophthalmitis-inducing bacteria ( Staphylococcus epidermidis, Propionibacterium acnes).

Materials And Methods: A total of 14 Dynasilan-treated and 14 untreated silicone lenses were incubated at 37 degrees C for 24 h in brain heart infusion broth (10(8) CFU/ml) either with Staphylococcus epidermidis or with Propionibacterium acnes for 1 h.

Determination of the solubility of perfluorocarbon liquids in silicone oil in vitro and in vivo.

Purpose: To investigate the solubility of perfluorocarbon liquids (PFCL) in silicone oil.

Methods: Forty-eight samples of silicone oil (1,300 mPas, n = 22; 5,000 mPas, n = 26) were analyzed for dissolved fluorocarbon molecules after surgical removal from patients who had initially undergone vitreoretinal surgery with (n = 41) and as control without (n = 7) the use of perfluorodecalin in headspace gas chromatography. In vitro, the solubility of three different PFCL-perfluorooctane (PFO), perfluorodecalin (PFD), and fluoromethylcyclohexane (FMCH)-in silicone oil of various viscosities was determined.

Combined use of partially fluorinated alkanes, perfluorocarbon liquids and silicone oil: an experimental study.

Background: Partially fluorinated alkanes (FALKs) are a new class of substances which can be used in vitreoretinal surgery as an intraoperative tool and as a long-term tamponade. The aim of this in vitro study was (1) to investigate the solubility of FALKs in silicone oil during direct exchange, (2) to study their combined use and solubility in PFCLs, (3) to evaluate their lipophilic properties and (4) to investigate the possibility of preparing "heavy silicone oil".

Methods: (1) Four different FALKs (F6H6, F6H8, O44 and O62) were directly exchanged with silicone oil (5,000 mPas).

Use of O44 as a solvent for silicone oil adhesions on intraocular lenses.

Purpose: To describe a solvent that removes silicone oil adhesions on intraocular lenses (IOLs).

Method: The solvent O44 is a partially fluorinated alcane that dissolves silicone oil. Silicone oil adhesions on silicone and poly(methyl methacrylate) IOLs were treated with O44.

[O44--a solvent for silicone oil adhesions on intraocular lenses].

Aim: To examine the efficiency of O44, a partial fluorinated octane, as a solvent for silicone oil adhesions on intraocular lenses.

Materials And Methods: After placing silicone- and PMMA-lenses in silicone oil, the adhesions were treated with O44. The extent of silicone oil adhesions and the effectiveness of O44 were studied by gross microscopy by scanning electrone microscopy (SEM) and combined energy dispersive spectrometry (EDX).

Temporary vitreous gas tamponade by perfluoromethylcyclopentane.

Using perfluoromethylcyclopentane (FMCP; US patent no. 5,441,989, granted 1995) we have developed a new vitreous gas tamponade in a rabbit model that allows complete filling of the vitreous cavity without vitrectomy and without a significant increase in intraocular pressure. In humans this procedure would allow the blockage of inferior and posterior retinal holes without special positioning of the patient.

[Amplitude changes in distortion products of otoacoustic emissions after acute noise exposure].

Background: The inner ear responds to acute impact of high-intensity noise with a temporary threshold shift (TTS), which represents a reaction of the outer hair cells. That is why TTS should be detectable as changes of distortion-product otoacoustic emissions (DPOAE).

Methods: DPOAE were measured in 102 ears in 59 test subjects with normal hearing before and after definitive noise exposure (20 min of "white noise" at 90 dB HL).