Age-related compaction of lens fibers affects the structure and optical properties of rabbit lenses

Aim: Comparative immunohistochemical study of expression of α A Crystallin in non-cataract lenses and age-related cataract lenses in humans. Methodology: This was an observational cross sectional study. There are two groups in this study. Group A comprised of 121 senile degenerative cataract lenses from diagnosed patients. Group B included of 10 non-cataract lenses from patients who underwent surgeries for enucleation due to trauma and retinoblastoma. Lenses were fixed in 10% Buffered Neutral Formalin and processed to make paraffin blocks. Immunohistochemistry (IHC) staining was performed on sections using primary antibody for α A crystallin. Data was analyzed through SPSS software version 24. Results: Immunohistochemical staining of group A showed 80.2% Strong Positive expression while 19.8% showed Intermediate Positive expression of α A Crystallin. 100% Strong Positive expression of α A Crystallin was seen in group B. Comparison of expression of α A Crystallin in two groups showed significant decrease (p<0.001) in expression. Conclusion: Decreased expression of α A Crystallin in IHC stained senile cataract lens indicates the role of structural alterations of lens fibers in pathogenesis of senile cataract. If mechanism involved in causing these alterations can be identified and targeted so that progression of senile cataract may be delayed. Keywords: Immunohistochemistry, α A crystallin expression, senile cataract, Human eye Lens, Lens Fiber.

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In vivo study of age-related changes in the optical properties of the skin

Lasers in Medical Science ◽

10.1007/s10103-009-0725-9 ◽

2009 ◽

Vol 25 (2) ◽

pp. 269-274 ◽

Cited By ~ 9

Author(s):

Mihaela Antonina Calin ◽

S. V. Parasca

Keyword(s):

Optical Properties ◽

In Vivo Study ◽

Age Related ◽

Age Related Changes

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Crescentic Cataracts in Alderley Park Rats

Veterinary Pathology ◽

10.1177/030098589303000109 ◽

1993 ◽

Vol 30 (1) ◽

pp. 70-74 ◽

Cited By ~ 4

Author(s):

C. M. Lazenby ◽

F. R. Westwood ◽

P. Greaves

Keyword(s):

Lens Capsule ◽

Sex Hormone ◽

Clinical Evolution ◽

Lens Fibers ◽

Age Related ◽

Hormone Status ◽

Microscopic Features ◽

Posterior Direction ◽

Long Term Studies

The ophthalmoscopic appearances and the clinical evolution of a previously poorly documented form of crescentic cataract was studied in over 2,000 untreated Alderley Park rats between 4 and 110 weeks of age. In addition, 401 ex-breeder females, 54 gonadectomized males, and 56 gonadectomized females of the same strain were studied. The light microscopic features of the lenticular changes were also examined in detail. The cataracts, crescentic in shape and originating dorsally at the lens equator, were mostly unilateral. They appeared from about 30 weeks of age and affected 4% of intact males and 14% of intact females by about 2 years of age. Fewer cataracts were found in ex-breeder females, and none were found in male or female gonadectomized rats up to 2 years of age. The cataracts developed rapidly and became fully formed in 3 months. Subsequently, most cataracts scarcely progressed. Only a few extended to involve the entire lens. Some appeared to regress completely. Histologically, affected lens fibers showed swelling, globular disintegration, and liquefaction, most marked in the cortex medial to the lens bow area and extending along the direction of the lens fibers in an anterior and posterior direction but only occasionally reaching the lens capsule. The cause of these age-related lenticular changes in the Alderley Park rat is uncertain, but these changes are important during the conduct of long-term studies with this strain because their incidence can be modulated by agents that alter sex hormone status.

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Analysis of Optical Properties of Posterior Surface of Cornea in Patients after Anterior Radial Keratotomy

Acta biomedica scientifica ◽

10.29413/abs.2019-4.4.3 ◽

2019 ◽

Vol 4 (4) ◽

pp. 24-29

Author(s):

E. K. Tsyrenzhapova ◽

O. I. Rozanova ◽

N. N. Seliverstova

Keyword(s):

Optical Properties ◽

Careful Analysis ◽

Radius Of Curvature ◽

Control Group ◽

Posterior Surface ◽

Anterior Surface ◽

Radial Keratotomy ◽

Age Related ◽

Anatomical Properties ◽

Posterior Cornea

Taking into account the constant increase in patients with age-related cataracts after radial keratotomy, a careful analysis of both the optical and anatomical properties of the cornea with the examination of the posterior surface is of particular importance.Aim. To analyze the optical properties of the posterior surface of the cornea in patients after anterior radial keratotomy. Materials and methods. An examination of 24 patients (48 eyes) with age-related cataracts of varying degrees of density, myopia and the presence of a previous anterior radial keratotomy or radial-tangential keratotomy in history. The average age of patients was 59.5 years (from 47 to 68), there were 19 women and 5 men.Results. The radius of curvature of the anterior surface in patients after anterior radial keratotomy was 9.45 ± 0.91 mm on average along the meridians, which is significantly more in comparison with these indices in control patients – 7.70 ± 0.19 mm (p = 0.0001). The ratio of the radii of the posterior cornea curvature to the anterior radius on average along the meridians in patients after anterior radial keratotomy was 1.07 ± 0.70, and in control patients – 1.20 ± 0.02 (p = 0.0001). The keratometric index in patients after anterior radial keratotomy was 1.3538 ± 0.0239, and in the control group – 1.3372 ± 0.0003 (p = 0.23).Conclusion. In patients after anterior radial keratotomy, keratometry of the posterior surface of the cornea is significantly higher than in the control. The ratio of the radius of curvature of the posterior cornea to the radius of curvature of the anterior cornea varies significantly after anterior radial keratotomy, which is due to a more pronounced flattening of the posterior cornea. The standard keratometric index (1.3375) is invalid for patients after anterior radial keratotomy and must be calculated individually for each patient when deciding on the operative treatment of cataracts.

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Design of objective lens for 200-kV high-resolution electron microscopes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075361 ◽

1983 ◽

Vol 41 ◽

pp. 314-315

Author(s):

K. Tsuno ◽

T. Honda ◽

Y. Harada ◽

M. Naruse

Keyword(s):

Optical Properties ◽

Computer Technology ◽

Axial Magnetic Field ◽

Chromatic Aberration ◽

Objective Lens ◽

Resolution Electron ◽

Correction Of Astigmatism ◽

Three Stages ◽

Electron Microscopes ◽

Stage 1

Developement of computer technology provides much improvements on electron microscopy, such as simulation of images, reconstruction of images and automatic controll of microscopes (auto-focussing and auto-correction of astigmatism) and design of electron microscope lenses by using a finite element method (FEM). In this investigation, procedures for simulating the optical properties of objective lenses of HREM and the characteristics of the new lens for HREM at 200 kV are described.The process for designing the objective lens is divided into three stages. Stage 1 is the process for estimating the optical properties of the lens. Firstly, calculation by FEM is made for simulating the axial magnetic field distributions Bzc of the lens. Secondly, electron ray trajectory is numerically calculated by using Bzc. And lastly, using Bzc and ray trajectory, spherical and chromatic aberration coefficients Cs and Cc are numerically calculated. Above calculations are repeated by changing the shape of lens until! to find an optimum aberration coefficients.

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Optical Properties of HVEM Accelerators

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100114529 ◽

1975 ◽

Vol 33 ◽

pp. 180-181

Author(s):

A. Strojnik ◽

J.W. Scholl ◽

V. Bevc

Keyword(s):

Optical Properties ◽

Electron Accelerator ◽

Systematic Investigation ◽

Electron Source ◽

High Brightness ◽

The Past ◽

Wide Range ◽

Optical Behavior

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).

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Differential polarization imaging of sickled cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102390 ◽

1988 ◽

Vol 46 ◽

pp. 62-63

Author(s):

Marcos F. Maestre

Keyword(s):

Optical Properties ◽

Theoretical Approach ◽

Polarized Light ◽

Polarization Microscopy ◽

Spectroscopic Techniques ◽

Polarization Imaging ◽

Circularly Polarized Light ◽

Circularly Polarized ◽

Microscopic Scale ◽

Chiral Structures

Recently we have developed a form of polarization microscopy that forms images using optical properties that have previously been limited to macroscopic samples. This has given us a new window into the distribution of structure on a microscopic scale. We have coined the name differential polarization microscopy to identify the images obtained that are due to certain polarization dependent effects. Differential polarization microscopy has its origins in various spectroscopic techniques that have been used to study longer range structures in solution as well as solids. The differential scattering of circularly polarized light has been shown to be dependent on the long range chiral order, both theoretically and experimentally. The same theoretical approach was used to show that images due to differential scattering of circularly polarized light will give images dependent on chiral structures. With large helices (greater than the wavelength of light) the pitch and radius of the helix could be measured directly from these images.

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A transmission electron microscopic study of structural transitions in fast ionic conductors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100125713 ◽

1987 ◽

Vol 45 ◽

pp. 156-157

Author(s):

R. B. Queenan ◽

P. K. Davies

Keyword(s):

Optical Properties ◽

Ionic Conduction ◽

Recent Observation ◽

Ionic Conductivities ◽

Sodium Aluminate ◽

Two Dimensions ◽

Ionic Conductors ◽

Electron Microscopic ◽

Transmission Electron ◽

Trivalent Cations

Na ß“-alumina (Na1.67Mg67Al10.33O17) is a non-stoichiometric sodium aluminate which exhibits fast ionic conduction of the Na+ ions in two dimensions. The Na+ ions can be exchanged with a variety of mono-, di-, and trivalent cations. The resulting exchanged materials also show high ionic conductivities.Considerable interest in the Na+-Nd3+-ß“-aluminas has been generated as a result of the recent observation of lasing in the pulsed and cw modes. A recent TEM investigation on a 100% exchanged Nd ß“-alumina sample found evidence for the intergrowth of two different structure types. Microdiffraction revealed an ordered phase coexisting with an apparently disordered phase, in which the cations are completely randomized in two dimensions. If an order-disorder transition is present then the cooling rates would be expected to affect the microstructures of these materials which may in turn affect the optical properties. The purpose of this work was to investigate the affect of thermal treatments upon the micro-structural and optical properties of these materials.

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Spindle shaped bodies in foveolar cones of the baboon retina

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015678x ◽

1989 ◽

Vol 47 ◽

pp. 960-961

Author(s):

W. Krebs ◽

I. Krebs

Keyword(s):

Cross Sections ◽

Inclusion Bodies ◽

Photoreceptor Cells ◽

Papio Anubis ◽

Retinal Photoreceptor ◽

Age Related ◽

Cone Cells ◽

Membrane Bound ◽

Oriented Parallel ◽

Shaped Inclusion

Various inclusion bodies occur in vertebrate retinal photoreceptor cells. Most of them are membrane bound and associated with phagocytosis or they are age related residual bodies. We found an additional inclusion body in foveal cone cells of the baboon (Papio anubis) retina.The eyes of a 15 year old baboon were fixed by immersion in cacodylate buffered glutaraldehyde (2%)/formaldehyde (2%) as described in detail elsewhere . Pieces of retina from various locations, including the fovea, were embedded in epoxy resin such that radial or tangential sections could be cut.Spindle shaped inclusion bodies were found in the cytoplasm of only foveal cones. They were abundant in the inner segments, close to the external limiting membrane (Fig. 1). But they also occurred in the outer fibers, the perikarya, and the inner fibers (Henle’s fibers) of the cone cells. The bodies were between 0.5 and 2 μm long. Their central diameter was 0.2 to 0. 3 μm. They always were oriented parallel to the long axis of the cone cells. In longitudinal sections (Figs. 2,3) they seemed to have a fibrous skeleton that, in cross sections, turned out to consist of plate-like (Fig.4) and tubular profiles (Fig. 5).

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Practical Correction of Three Fold Astigmatism in the Philips CM TEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164556 ◽

1996 ◽

Vol 54 ◽

pp. 418-419

Author(s):

Arno J. Bleeker ◽

Mark H.F. Overwijk ◽

Max T. Otten

Keyword(s):

Optical Properties ◽

Phase Contrast ◽

The Other ◽

Objective Lens ◽

Symmetric Part ◽

A Posteriori ◽

Contrast Transfer Function ◽

High Brightness ◽

Rotationally Symmetric ◽

Brightness Field

With the improvement of the optical properties of the modern TEM objective lenses the point resolution is pushed beyond 0.2 nm. The objective lens of the CM300 UltraTwin combines a Cs of 0. 65 mm with a Cc of 1.4 mm. At 300 kV this results in a point resolution of 0.17 nm. Together with a high-brightness field-emission gun with an energy spread of 0.8 eV the information limit is pushed down to 0.1 nm. The rotationally symmetric part of the phase contrast transfer function (pctf), whose first zero at Scherzer focus determines the point resolution, is mainly determined by the Cs and defocus. Apart from the rotationally symmetric part there is also the non-rotationally symmetric part of the pctf. Here the main contributors are not only two-fold astigmatism and beam tilt but also three-fold astigmatism. The two-fold astigmatism together with the beam tilt can be corrected in a straight-forward way using the coma-free alignment and the objective stigmator. However, this only works well when the coefficient of three-fold astigmatism is negligible compared to the other aberration coefficients. Unfortunately this is not generally the case with the modern high-resolution objective lenses. Measurements done at a CM300 SuperTwin FEG showed a three fold-astigmatism of 1100 nm which is consistent with measurements done by others. A three-fold astigmatism of 1000 nm already sinificantly influences the image at a spatial frequency corresponding to 0.2 nm which is even above the point resolution of the objective lens. In principle it is possible to correct for the three-fold astigmatism a posteriori when through-focus series are taken or when off-axis holography is employed. This is, however not possible for single images. The only possibility is then to correct for the three-fold astigmatism in the microscope by the addition of a hexapole corrector near the objective lens.

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