scholarly journals Microscopic Characteristics of Late Intraocular Lens Opacifications

2020 ◽  
Author(s):  
Piotr Kanclerz ◽  
Timur Mert Yildirim ◽  
Ramin Khoramnia
Keyword(s):  
Intraocular Lens ◽  
Room Temperature ◽  
English Language ◽  
Critical Issue ◽  
Intraocular Lenses ◽  
Alizarin Red ◽  
Younger Patients ◽  
X Ray ◽  
International Laboratory ◽  
Hydrophobic Acrylic

Context.— The increases in overall life expectancy and in lens surgeries performed on younger patients have resulted in a significant increase in the anticipated duration of artificial intraocular lenses (IOLs) in the eye. Thus, the physicochemical properties of the IOL become a critical issue, and several types of postoperative IOL opacifications have been reported. Objective.— To describe the microscopic characteristics of opacified IOLs. Glistenings and subsurface nanoglistenings are fluid-related phenomena developing mainly in hydrophobic acrylic IOLs and are associated with aqueous influx into the IOL matrix. Calcification presents in hydrophilic acrylic or silicone IOLs as deposits of hydroxyapatite or other phases of calcium. Snowflake degeneration is less common, and it manifests in older polymethyl methacrylate IOLs. Data Sources.— PubMed and ScienceDirect databases were searched for the following keywords: intraocular lens, IOL, cataract surgery, phacoemulsification, opacification, glistening, subsurface nanoglistenings, calcification, snowflake degeneration. English-language articles published up to October 15, 2019 were included in the study. The manuscript contains mainly a literature review; however, it was supplemented with original investigations from the David J. Apple International Laboratory for Ocular Pathology Conclusions.— Glistenings and subsurface nanoglistenings should be evaluated in hydrated state and at room temperature; they manifest as microvacuoles sized from 1.0 to greater than 25.0 μm and less than 200 nm, respectively. Calcification deposits are situated on or underneath the surface of the IOL and can be stained with a 1% alizarin red solution or with the von Kossa method. Snowflake degeneration manifests as “particles” or “crystals,” causing whitish IOL discoloration. Scanning electron microscopy or energy dispersive X-ray spectroscopy may improve the diagnostic accuracy.

scholarly journals Silicone Oil Adhesion to Hydrophobic Acrylic Intraocular Lenses: A Comparative Laboratory Study of a New versus an Established Hydrophobic Acrylic Intraocular Lens Material

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Gerd U. Auffarth ◽  
Hui Fang ◽  
Qiang Wang ◽  
Fritz Hengerer ◽  
Ramin Khoramnia ◽  
...  
Keyword(s):  
Intraocular Lens ◽  
Room Temperature ◽  
Silicone Oil ◽  
Total Surface Area ◽  
Intraocular Lenses ◽  
Aqueous Sodium Chloride Solution ◽  
In Vitro Assessment ◽  
Lens Material ◽  
Hydrophobic Acrylic

Background. In vitro assessment of silicone oil adhesion to a new hydrophobic acrylic intraocular lens (IOL) material, the Clareon model CNA0T0, compared with the established AcrySof model SN60WF was carried out. Methods. Silicone oil adhesion was assessed for two types of IOLs, Clareon CNA0T0 (n = 10) and AcrySof SN60WF (n = 10). Lenses were immersed in an aqueous sodium chloride solution for 12 hours and then incubated at room temperature in silicone oil for 12 hours. The lenses were washed with distilled water and photographed at 25x magnification using a microscope. The percent coverage was calculated by dividing the area of oil coverage by the total surface area of the lens. Results. Silicone oil adhesion to the surface of the CNA0T0 lens ranged from 4% to 22%, with a mean ± SD coverage of 8% ± 4%. Silicone oil adhesion to the surface of the SN60WF lens ranged from 1% to 17%, with a mean coverage of 9% ± 4%. The silicone oil adhesion of CNA0T0 was equivalent to that of SN60WF ( P > 0.05 ). Conclusions. The new Clareon model CNA0T0 IOL has silicone oil adhesion and interaction that are equivalent to the established AcrySof IOL.

scholarly journals Late Opacification of Foldable Intraocular Lenses

2012 ◽  
Vol 46 (2) ◽  
pp. 95-97
Author(s):  
Nishant Gupta ◽  
Jagat Ram ◽  
Manish Chaudhary ◽  
Jaspreet Singh Sukhija ◽  
Jaidrath Kumar
Keyword(s):  
Diabetes Mellitus ◽  
Intraocular Lens ◽  
Manufacturing Process ◽  
Case Series ◽  
Intraocular Lenses ◽  
Hydrophobic Acrylic ◽  
Iol Exchange

ABSTRACT Objective To report opacification of hydrophilic acrylic and silicone foldable intraocular lenses (IOL). Designs Case series. Participants Five patients with IOL opacification. Results We report five eyes of five patients with late opacification of the intraocular lens (IOL). Three patients had hydrophilic acrylic (SC60B-OUV-MDR, Inc), two had silicone IOL (Allergan SI30NB). Two out of the three patients with opacified hydrophilic acrylic IOLs had diabetes mellitus. Three eyes with opacified acrylic IOL underwent IOL exchange with hydrophobic acrylic IOL. Two silicone IOL patients had no visually significant opacification and were managed conservatively. Conclusion IOL optic opacification in hydrophilic acrylic and silicone IOL may be due to defective material, manufacturing process, storage. How to cite this article Ram J, Gupta N, Chaudhary M, Sukhija JS, Gupta A, Kumar J. Late Opacification of Foldable Intraocular Lenses. J Postgrad Med Edu Res 2012;46(2):95-97.

Scanning electron microscopic characteristics of manually loaded and preloaded foldable acrylic intraocular lenses

2018 ◽  
Vol 29 (1) ◽  
pp. 28-32
Author(s):  
Mahmoud Fathy Rateb ◽  
Zeiad Hasan Eldaly ◽  
Walid Saad Eldein Ibrahim ◽  
Ahmed Hasan Eldoghaimy
Keyword(s):  
Intraocular Lens ◽  
Visual Outcome ◽  
Intraocular Lenses ◽  
Common Finding ◽  
Control Group ◽  
Optical Surface ◽  
Electron Microscopic ◽  
The Impact ◽  
Hydrophobic Acrylic ◽  
Scanning Electron

Purpose: To compare surface alterations between preloaded and manually loaded intraocular lens. Methods: Scanning electron microscope was utilized to evaluate surface alteration and deposits in four different types of intraocular lenses: preloaded hydrophobic acrylic, preloaded hydrophilic acrylic, manually loaded hydrophobic acrylic, and manually loaded hydrophilic acrylic. Six lenses with different powers (+6 D, +22 D, and +29 D) were used from each category, to represent different thickness categories of the intraocular lenses. Results: In total, 30 intraocular lenses have been evaluated in this study: 4 from the control group (2 hydrophobic and 2 hydrophilic lenses) and 12 from the preloaded intraocular lens and manually loaded groups (6 hydrophilic and 6 hydrophobic lenses with different powers). Surface deposits were found in eight hydrophobic intraocular lenses compared to a single intraocular lens with scattered deposits on the optical surface of a hydrophilic intraocular lens. In manually loaded intraocular lens group, five hydrophobic and one hydrophilic intraocular lenses showed identifiable marks on the optical surface. In the preloaded intraocular lens group, three hydrophobic intraocular lenses showed identifiable marks on the optical surface and three hydrophobic intraocular lenses showed surface wrinkling. All hydrophilic intraocular lenses revealed no identifiable marks. Conclusion: Surface alterations and deposits are a common finding in both preloaded and manually loaded intraocular lenses. Water content of acrylic intraocular lenses is an important factor predisposing to these changes, and hydrophobic intraocular lenses are more vulnerable than hydrophilic lenses. The impact on the final visual outcome needs further studies.

scholarly journals Opacification of hydrophilic intraocular lenses associated with vitrectomy and injection of intraocular gas

2018 ◽  
Vol 3 (1) ◽  
pp. e000157 ◽  
Author(s):  
Arie L Marcovich ◽  
Tamer Tandogan ◽  
Mor Bareket ◽  
Eva Eting ◽  
Ifat Kaplan-Ashiri ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Gas Injection ◽  
Intraocular Lenses ◽  
Calcium Deposition ◽  
Alizarin Red ◽  
Iol Implantation ◽  
X Ray ◽  
Intraocular Gas ◽  
Pars Plana ◽  
Intravitreal Gas

ObjectiveTo report 11 cases of intraocular lens (IOL) opacification after pars plana vitrectomy (PPV) involving intravitreal gas injection.Methods and analysisEleven cases of hydrophilic IOLs that opacified following PPV with intravitreal gas injection are described. Eight IOLs were explanted and analysed by light microscopy and scanning electron microscopy. Staining with alizarin red and von Kossa stains, as well as energy dispersive X-ray spectroscopy (EDX) were performed. Three IOLs were not explanted. The surgeons attached the clinical data.ResultsThe IOLs were hydrophilic acrylic produced by six manufacturers. Six patients underwent primarily phacoemulsification with IOL implantation. PPV with intravitreal gas injection was performed 3 months–6 years afterwards. The other five patients underwent combined phacoemulsification with IOL implantation and PPV with intravitreal gas injection. IOL opacification was recorded 1 month –6 years after PPV. In eight patients, the IOLs were explanted 1 month–9 years after opacification was noticed. In three patients, the opacified IOL was not explanted. IOLs had opacified mainly anteriorly at the pupillary entrance or capsulorhexis opening. Light microscopy demonstrated granular surface deposits on the IOLs that stained positive for calcium by alizarin red and von Kossa stains. EDX analysis of the deposits detected calcium and phosphorus.ConclusionsHydrophilic acrylic IOLs can opacify due to calcium deposition after PPV and intravitreal gas injection and may require IOL explantation. A hydrophobic IOL may be preferred when a simultaneous phacoemulsification and vitrectomy with intravitreal gas is performed.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

Opening images of synaptic vesicles and calcium localization by means of microwave fixation method

1990 ◽  
Vol 48 (2) ◽  
pp. 182-183
Author(s):  
Vinci Mizuhira ◽  
Hiroshi Hasegawa
Keyword(s):  
Synaptic Vesicles ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Sampling Procedure ◽  
Fixation Method ◽  
Potassium Oxalate ◽  
X Ray ◽  
Cacodylate Buffer ◽  
Ultrathin Sections ◽  
Microwave Fixation

Microwave irradiation (MWI) was applied to 0.3 to 1 cm3 blocks of rat central nervous system at 2.45 GHz/500W for about 20 sec in a fixative, at room temperature. Fixative composed of 2% paraformaldehyde, 0.5% glutaraldehyde in 0.1 M cacodylate buffer at pH 7.4, also contained 2 mM of CaCl2 , 1 mM of MgCl2, and 0.1% of tannic acid for conventional observation; and fuether 30-90 mM of potassium oxalate containing fixative was applied for the detection of calcium ion localization in cells. Tissue blocks were left in the same fixative for 30 to 180 min after MWI at room temperature, then proceeded to the sampling procedure, after postfixed with osmium tetroxide, embedded in Epon. Ultrathin sections were double stained with an useal manner. Oxalate treated sections were devided in two, stained and unstained one. The later oxalate treated unstained sections were analyzed with electron probe X-ray microanalyzer, the EDAX-PU-9800, at 40 KV accelerating voltage for 100 to 200 sec with point or selected area analyzing methods.

Evidence for ordered Fe3Ni

1987 ◽  
Vol 45 ◽  
pp. 216-217
Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Experimental Data ◽  
Martensitic Transformation ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Direct Evidence ◽  
Transformation Product ◽  
Iron Meteorites ◽  
X Ray ◽  
Ni Content ◽  
Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

Electron Microscope study of commensurate-incommensurate phase transition in BaZnGeO4

1990 ◽  
Vol 48 (4) ◽  
pp. 172-173
Author(s):  
Naoki Yamamoto ◽  
Makoto Kikuchi ◽  
Tooru Atake ◽  
Akihiro Hamano ◽  
Yasutoshi Saito
Keyword(s):  
Phase Transition ◽  
Electron Microscope Study ◽  
Room Temperature ◽  
Hexagonal Lattice ◽  
Ferroelectric Materials ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Periodic Arrays ◽  
Modulation Wave Vector

BaZnGeO4 undergoes many phase transitions from I to V phase. The highest temperature phase I has a BaAl2O4 type structure with a hexagonal lattice. Recent X-ray diffraction study showed that the incommensurate (IC) lattice modulation appears along the c axis in the III and IV phases with a period of about 4c, and a commensurate (C) phase with a modulated period of 4c exists between the III and IV phases in the narrow temperature region (—58°C to —47°C on cooling), called the III' phase. The modulations in the IC phases are considered displacive type, but the detailed structures have not been studied. It is also not clear whether the modulation changes into periodic arrays of discommensurations (DC’s) near the III-III' and IV-V phase transition temperature as found in the ferroelectric materials such as Rb2ZnCl4.At room temperature (III phase) satellite reflections were seen around the fundamental reflections in a diffraction pattern (Fig.1) and they aligned along a certain direction deviated from the c* direction, which indicates that the modulation wave vector q tilts from the c* axis. The tilt angle is about 2 degree at room temperature and depends on temperature.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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