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1.
Cureus ; 16(5): e59878, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38854231

RESUMO

Background Psoriasis is a papulosquamous disease with variable morphology, distribution, severity, and course. Chronic plaque psoriasis, or psoriasis vulgaris, is the most common form of psoriasis. Present available preparations for mild to moderate chronic plaque psoriasis for topical use are local corticosteroids, coal tar, dithranol, tazarotene, calcipotriol, tapinarof, and calcineurin inhibitors. However, every preparation has its disadvantages. Calcipotriol, an active form of vitamin D, is available in topical form for dermatological use. Chronic plaque psoriasis is the chief medical use of calcipotriol for mild to moderate form. Methotrexate has dramatic results in psoriasis when used systemically. Now, topical formulation is being advocated in localized psoriasis, which is not associated with the side effects of the systemic form. Therefore, this study aimed to compare the effectiveness of topical calcipotriol and topical methotrexate on the basis of the psoriasis area severity index (PASI) in patients of chronic plaque psoriasis and compare their safety in terms of adverse effects. Methodology The total number of patients included in the study was 60. They were divided into two groups, with 30 patients each. One group was prescribed ointment calcipotriol 0.005% twice daily local application (Group C). The other group was prescribed methotrexate gel 1% twice daily local application (Group M). The patients were followed up on the fourth and eighth weeks, and at each time, thorough clinical examinations were conducted for all patients. The PASI score was calculated in each patient every time. Safety was assessed by biochemical parameters, and tolerability was assessed by the incidence of adverse effects. All the patients included in the study were investigated at baseline, fourth week, and eighth week. The data collected were transferred to a master chart and analyzed. Results For the patients in group C, the mean PASI score at 0 week was 5.93 ± 2.62, while at four weeks, the mean PASI score declined to 1.67 ± 1.13, and at eight weeks, the mean PASI score further declined to 0.67 ± 0.68. For the patients in group M, the mean PASI score at 0 week was 5.91 ± 2.22, while at four weeks, the mean PASI score declined to 1.91 ± 1.11, and at eight weeks, the mean PASI score further declined to 0.89 ± 0.72. Furthermore, there was no significant difference in the mean PASI score at various time points when compared between the two groups (p-value = 0.761, 0.296, 0.079, respectively). Thus, both drugs seem to be effective in treating mild- to moderate-grade chronic plaque psoriasis. Most of the patients in both groups showed marked clearance of the lesions. However, there were six patients in the calcipotriol group showing complete clearance of the lesions having mild-degree plaque psoriasis, as compared to three patients in the methotrexate group. In the present study, based on the comparison of safety and tolerability, four out of 30 patients (13.3%) in the calcipotriol group suffered skin irritation, whereas six out of 30 patients (20%) in the methotrexate group complained of a burning sensation. The adverse effects seen in the patients were transient and mild. Conclusion Topical calcipotriol and methotrexate were effective in reducing lesions in patients with chronic mild to moderate plaque psoriasis. Both drugs were well tolerated with mild and transient adverse effects and did not alter hematological and biochemical parameters.

2.
Phys Rev Lett ; 132(9): 096302, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38489650

RESUMO

The valley Hall effect arises from valley-contrasting Berry curvature and requires inversion symmetry breaking. Here, we propose a nonlinear mechanism to generate a valley Hall current in systems with both inversion and time-reversal symmetry, where the linear and second-order charge Hall currents vanish along with the linear valley Hall current. We show that a second-order valley Hall signal emerges from the electric field correction to the Berry curvature, provided a valley-contrasting anisotropic dispersion is engineered. We demonstrate the nonlinear valley Hall effect in tilted massless Dirac fermions in strained graphene and organic semiconductors. Our Letter opens up the possibility of controlling the valley degree of freedom in inversion symmetric systems via nonlinear valleytronics.

3.
Nano Lett ; 23(15): 6792-6798, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37477991

RESUMO

In this Letter, we provide experimental evidence of the time-reversal symmetric Hall effect in a mesoscopic system, namely, high-mobility graphene-WSe2 heterostructures. This linear, dissipative Hall effect, whose sign depends on the sign of the charge carriers, persists up to room temperature. The magnitude and the sign of the Hall signal can be tuned using an external perpendicular electric field. Our joint experimental and theoretical study establishes that the strain induced by lattice mismatch, or alignment angle inhomogeneity, produces anisotropic bands in graphene while simultaneously breaking the inversion symmetry. The band anisotropy and reduced spatial symmetry lead to the appearance of a time-reversal symmetric Hall effect. Our study establishes graphene-transition metal dichalcogenide-based heterostructures as an excellent platform for studying the effects of broken symmetry on the physical properties of band-engineered two-dimensional systems.

4.
Phys Rev Lett ; 129(22): 227401, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36493457

RESUMO

Nonlinear responses are actively studied as probes of topology and band geometric properties of solids. Here, we show that second harmonic generation serves as a probe of the Berry curvature, quantum metric, and quantum geometric connection. We generalize the theory of second harmonic generation to include Fermi surface effects in metallic systems, and finite scattering timescale. In doped materials the Fermi surface and Fermi sea cause all second harmonic terms to exhibit resonances, and we identify two novel contributions to the second harmonic signal: a double resonance due to the Fermi surface and a higher-order pole due to the Fermi sea. We discuss experimental observation in the monolayer of time reversal symmetric Weyl semimetal WTe_{2} and the parity-time reversal symmetric topological antiferromagnet CuMnAs.


Assuntos
Microscopia de Geração do Segundo Harmônico , Feminino , Gravidez , Humanos , Frutas , Vibração
5.
Opt Express ; 30(15): 27140-27148, 2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-36236891

RESUMO

Light emitting diodes (LEDs) have become a major source of lighting conditions. The increased prevalence of LED light sources introduces new concerns for the spectral effects of positive dysphotopsia (PD) or glare type photic phenomena for pseudo-phakic patients with intraocular lenses (IOLs). A significant amount of work has been published in the area of spectral discomfort and sensitivity of LEDs as well as automotive lighting. The wavelength dependence or spectral properties of PD due to LEDs for IOLs has not been reported. This study, to our knowledge, is the first one to assess the glare characteristics of four commercially available IOL models with different material types and design features using an optical bench and non-sequential ray trace simulations with LEDs of different wavelengths. A novel approach of representing the reflected and transmitted IOL glare utilizing Fresnel coefficients is found to be in close agreement with the measurements.


Assuntos
Ofuscação , Lentes Intraoculares , Humanos , Lentes Intraoculares/efeitos adversos , Desenho de Prótese , Transtornos da Visão/diagnóstico , Transtornos da Visão/etiologia
6.
RSC Adv ; 12(33): 21493-21502, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35975067

RESUMO

A highly efficient trans-esterification of ß-keto methyl/ethyl esters with primary, secondary, allylic, benzylic and chiral alcohols has been carried out in excellent yields under solvent-free conditions using silica supported boric acid as a heterogeneous catalyst. The surface morphology of the silica-boric acid catalyst (fresh and recycled) has been characterized by SEM and EDX techniques. This sustainable protocol resulted in a remarkable enhancement in the synthetic efficiency (87-95% yield) with high purity and eliminating the use of an environmentally toxic solvent. The work up procedure is very simple and the catalyst has been successfully recovered and recycled. The present methodology is also applicable for trans-esterification with chiral alcohols on a multi-gram scale without compromising the yield. Noteworthy features of this protocol are simple operational procedure, minimizing production of chemical waste, mild reaction conditions, easy preparation of the catalyst and its recyclability up to five cycles without any appreciable loss of catalytic activity.

7.
J Phys Condens Matter ; 32(42): 425002, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32590365

RESUMO

We report a metal-insulator like transition in single-crystalline 3D topological insulator Bi2Te3 at a temperature of 230 K in the presence of an external magnetic field applied normal to the surface. This transition becomes more prominent at larger magnetic field strength with the residual resistance value increasing linearly with the magnetic field. At low temperature, the magnetic field dependence of the magnetoresistance shows a transition from logarithmic to linear behavior and the onset magnetic field value for this transition decreases with increasing temperature. The logarithmic magnetoresistance indicates the weak anti-localization of the surface Dirac electrons while the high temperature behavior originates from the bulk carriers due to intrinsic impurities. At even higher temperatures beyond ∼230 K, a completely classical Lorentz model type quadratic behavior of the magnetoresistance is observed. We also show that the experimentally observed anomalies at ∼230 K in the magneto-transport properties do not originate from any stacking fault in Bi2Te3.

8.
J Genet ; 98(2)2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31204696

RESUMO

Evaluation of sequence variations in the internal transcribed spacer (ITS) region of 19 accessions, comprising of 11 accessions of Chenopodium quinoa, eight accessions of Chenopodium album and 165 retrieved sequences of different species of Chenopodium belonging to subfamily Chenopodioideae revealed a higher intraspecific genetic diversity in Himalayan C. album than that in C. quinoa. ITS and amplified fragment-length profiles of the accessions suggest the existence of accessions of Himalayan C. album as heteromorphs of the same species rather than a heterogenous assemblage of taxa. While the evolutionary relationship reconstructed from variations in 184 sequences of ITS region from species belonging to Chenopodiaceae, Amaranthaceae, Polygonaceae and Nelumbonaceae established a paraphyletic evolution of family Chenopodiaceae, it also revealed a monophyletic evolution of Chenopodieae I. The reconstruction also established five independent lineages of the subfamily Chenopodioideae with C. album as a sister clade of C. quinoa within the tribe Chenopodieae I. The results also indicate a much younger age for Himalayan chenopods (C. album) than the reported crown age of Chenopodieae I.


Assuntos
Chenopodium/classificação , Chenopodium/genética , DNA Espaçador Ribossômico/genética , Evolução Molecular , Variação Genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Biologia Computacional/métodos , Conformação de Ácido Nucleico , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
9.
J Cataract Refract Surg ; 45(4): 501-506, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30686704

RESUMO

PURPOSE: To compare mechanical characteristics and stability of Clareon CNA0T0 intraocular lens (IOL) with 4 currently marketed monofocal IOLs and to evaluate axial displacement and simulated dioptric power shift using a range of compression diameters. SETTING: Alcon Laboratories, Inc., Fort Worth, Texas, USA. DESIGN: Experimental study. METHODS: Clareon CNA0T0, AcrySof SN60WF, enVista MX60, Tecnis ZCB00, and Vivinex iSert XY1 IOLs (10 per group) were assessed using standardized methods for axial displacement, optic decentration, and optic tilt per the International Organization for Standardization ISO11979-3. Axial displacement was also measured over a range of compression diameters (9.0 to 11.0 mm). RESULTS: At 10.0 mm compression, the mean axial displacement for the CNA0T0 IOL (0.02 mm ± 0.01 [SD]) was significantly lower than for the MX60, ZCB00, and XY1 IOLs (P < .005). At all compression diameters, the CNA0T0 and SN60WF IOLs had the lowest levels of axial displacement and corresponding simulated dioptric power shift at the corneal plane versus other IOL models. At 10.0 mm compression, the mean optic decentration was within ±0.06 mm for all models, and there were no significant differences between the CNA0T0 IOL and other IOLs. At 10.0 mm compression, the mean optic tilt was no greater than 1.2 degrees for all IOL models evaluated; however, the mean optic tilt for the CNA0T0 IOL was significantly lower than for the MX60 IOL (P < .005). CONCLUSION: The CNA0T0 and SN60WF IOLs showed the lowest levels of axial displacement and corresponding simulated dioptric power shift over all tested compression diameters, indicating they might provide the most consistent refractive outcomes.


Assuntos
Fenômenos Biomecânicos , Lentes Intraoculares , Óptica e Fotônica , Resistência à Tração , Humanos , Refração Ocular/fisiologia , Acuidade Visual/fisiologia
10.
Heredity (Edinb) ; 122(1): 120-132, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29725078

RESUMO

Dioecy and the dynamics of its evolution are intensely investigated aspects of plant reproduction. Seabuckthorn (Hippophae rhamnoides ssp. turkestanica) is an alpine shrub growing wild in certain parts of western Himalaya. The previous studies have reported heteromorphic sex chromosomes in the species and yet marker-based studies indicate high similarity between the male and female genomes. Lack of information on sexual system in the species has further complicated the situation. A systematic study was thus undertaken to understand the sexual system in seabuckthorn and to discern the extent of similarity/dissimilarity between the male and female genomes by generating a large number of markers using amplified fragment length polymorphism and representational difference analysis. Floral biology and regular monitoring of species revealed the presence of polygamomonoecious (PGM) plants in most populations at a low percentage (~2-4%). PGM plants showed low pollen production and overall low fertility, suggesting a monoecy-paradioecy pathway at function. The results of the marker study demonstrated that there are limited differences between male and female genomes and these differences were not uniform across the populations in the Leh-Ladakh region, especially when the geographical distance increases. Results also suggest that a dynamic partitioning of genomes is operational between the two genders of seabuckthorn and differences are not homogenized across the populations. Both reproductive biology-based and DNA marker-based studies indicate that genders have separated recently. The present study proposes seabuckthorn as a promising model system to study evolution of dioecy and sex determination.


Assuntos
Genoma de Planta/genética , Hippophae/genética , Cromossomos Sexuais/genética , Processos de Determinação Sexual/genética , Evolução Molecular , Genes de Plantas/genética , Marcadores Genéticos/genética , Hippophae/crescimento & desenvolvimento , Polimorfismo Genético
11.
J Cataract Refract Surg ; 45(2): 219-227, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30471850

RESUMO

PURPOSE: To compare the glare-type photic phenomena for a new intraocular lens (IOL) to other monofocal IOLs, and to investigate how IOL design features might affect these phenomena. SETTING: Alcon Laboratories, Inc., Fort Worth, Texas; John A Moran Eye Center, University of Utah, Salt Lake City, USA. DESIGN: Schematic model eye evaluation and in vitro study. METHODS: Five monofocal IOL models (Clareon CNA0T0, Tecnis ZCB00, enVista MX60, Eternity W-60, and Vivinex XY1) were used to evaluate glare or positive dysphotopsia-type phenomena. Optical simulations of incoming light were generated using nonsequential ray-tracing software based on a collimated light source for various off-axis angles of illumination. The simulation analyses were verified using a laboratory in vitro bench-top glare measurement system. RESULTS: The Clareon and Vivinex IOLs produced focused off-axis images with negligible peripheral glare characteristics. The Tecnis and enVista IOLs produced dispersed images with additional glare characteristics at 45 degrees of off-axis illumination and higher. The Eternity IOL showed the highest edge-reflected glare characteristic, likely because of its straight optic edge geometry. The laboratory bench images and glare intensity profiles were consistent with the simulation data. CONCLUSIONS: In vitro and nonsequential ray-tracing evaluations showed that straight optic edges and peripheral nonimaging optic geometry might contribute to positive dysphotopsia. The IOL designs with optic edge curvature and full functional optics demonstrated the lowest level of glare-type photic phenomena. Only clinical studies can confirm whether the differences observed between the IOLs in vitro are clinically significant.


Assuntos
Catarata/fisiopatologia , Lentes Intraoculares , Luz , Óptica e Fotônica , Ofuscação , Humanos , Desenho de Prótese , Espalhamento de Radiação
12.
Protoplasma ; 254(2): 1063-1077, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27542084

RESUMO

Hippophae rhamnoides L. ssp. turkestanica (Elaeagnaceae) is a predominantly dioecious and wind-pollinated medicinal plant species. The mature fruits of the species possess antioxidative, anti-inflammatory, antimicrobial, anticancerous, and antistimulatory properties that are believed to improve the immune system. The identification of male and female plants in H. rhamnoides ssp. turkestanica is quite difficult until flowering which usually takes 3-4 years or more. A sex-linked marker can be helpful in establishing the orchards through identification of genders at an early stage of development. Therefore, we studied the genetic diversity of populations in Ladakh with the aim to identify a gender-specific marker using ISSR markers. Fifty-eight ISSR primers were used to characterize the genome of H. rhamnoides ssp. turkestanica, of which eight primers generated 12 sex-specific fragments specific to one or more populations. The ISSR primer (P-45) produced a fragment which faithfully segregates all the males from the female plants across all the three valleys surveyed. This male-specific locus was converted into a SCAR. Forward and reverse primers designed from this fragment amplified a 750-bp sequence in males only, thus specifying it as an informative male-specific sex-linked marker. This SCAR marker was further validated for its capability to differentiate gender on an additional collection of plants, representing three geographically isolated valleys (Nubra, Suru, and Indus) from Ladakh region of India. The results confirmed sex-linked specificity of the marker suggesting that this conserved sequence at the Y chromosome is well preserved through the populations in Ladakh region. At present, there are no reliable markers which can differentiate male from female plants across all the three valleys of Ladakh region at an early stage of plant development. It is therefore envisaged that the developed SCAR marker shall provide a reliable molecular tool for early identification of the sex in this commercial crop. The genetic diversity of populations as surveyed by ISSR primers revealed 85.71 % polymorphism at the population level. The dendrogram obtained divided the genotypes into three different clusters, and the distribution of male and female genotypes in all the clusters was random. The Nei's genetic similarity index was in the range of 0.63-0.96.


Assuntos
Altitude , Hippophae/crescimento & desenvolvimento , Hippophae/genética , Repetições de Microssatélites/genética , Sequência de Bases , DNA de Plantas/genética , Marcadores Genéticos , Genética Populacional , Geografia , Índia , Filogenia , Polimorfismo Genético , Análise de Componente Principal , Reprodutibilidade dos Testes
13.
Invest Ophthalmol Vis Sci ; 57(7): 3239-47, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27315539

RESUMO

PURPOSE: To evaluate light scatter and stray light in intraocular lenses (IOLs) explanted because of postoperative opacification (13 calcified hydrophilic acrylic, 1 calcified silicone, and 4 polymethylmethacrylate [PMMA] lenses with snowflake degeneration), as well as effect of opacification on other optical quality/performance indicators, in comparison with controls. METHODS: The Complete Angle Scatter Instrument (CASI) scatterometer was used to measure the forward light scattering (FLS) of the IOLs, and the stray light values at various angles were calculated from the measured FLS. Modulation transfer function (MTF) was obtained with an optical bench, and a Badal optometer was used to obtain letter chart images through the lenses. Back light scatter and light transmittance were also measured. RESULTS: Average stray light values (Log (s)) at a scattered angle of 10° were 1.79 ± 0.37 for hydrophilic acrylic IOLs (controls 0.36 ± 0.05), 1.53 for the silicone lens (control 0.41), and 1.62 ± 0.46 for PMMA IOLs (control 0.25). Stray light was significantly higher for explanted opacified lenses (N = 18) in comparison with controls (N = 7; two-tail P < 0.001 at 10°). Modulation transfer function and Badal image contrast were drastically reduced in lenses with calcification and snowflake degeneration. CONCLUSIONS: Different studies described the impact of stray light in human vision, with serious hindrance above 1.47 Log (s). Lenses explanted from patients because of clinically significant opacification are associated with a considerable increase in light scatter and stray light, as well as with a decline of other optical quality/performance indicators.


Assuntos
Resinas Acrílicas , Calcinose/diagnóstico , Lentes Intraoculares , Polimetil Metacrilato , Espalhamento de Radiação , Elastômeros de Silicone , Acuidade Visual/fisiologia , Materiais Biocompatíveis , Calcinose/cirurgia , Remoção de Dispositivo , Análise de Falha de Equipamento , Humanos , Luz , Óptica e Fotônica , Complicações Pós-Operatórias , Falha de Prótese
14.
J Cataract Refract Surg ; 42(1): 148-56, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26948790

RESUMO

PURPOSE: To evaluate forward light scattering and straylight in single-piece hydrophobic acrylic intraocular lenses (IOLs) (Acrysof) removed from cadaver eyes and design- and power-matched controls, as well as the effect of subsurface nanoglistenings on other optical quality and performance indicators. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Seventeen single-piece IOLs (11 blue light-filtering; 6 without blue-light filter) with subsurface nanoglistenings were removed from cadaver eyes. The Complete Angle Scatter Instrument scatterometer was used to measure the forward-scattered light; straylight values at various angles were calculated. The modulation transfer function (MTF) and Badal images were also obtained. Backscatter was measured with a Scheimpflug camera (EAS-1000) and light transmittance with a spectrophotometer (Lambda 35 UV-VIS) to confirm findings in previous studies. RESULTS: The mean straylight values at a scattered angle of 10 degrees were 1.06 ± 0.23 log(s) for blue light-filtering IOLs, 0.97 ± 0.28 log(s) for IOLs without a blue-light filter, and 0.22 ± 0.22 log(s) for controls. The MTF and Badal image contrast of IOLs removed from cadaver eyes were similar to control values (no subsurface nanoglistenings). Backscatter was significantly higher in IOLs from cadaver eyes, although light transmittance was similar to that of controls. CONCLUSION: Straylight in hydrophobic IOLs resulting from subsurface nanoglistenings was well below the value of straylight hindrance and would not cause noticeable visual impairments. FINANCIAL DISCLOSURE: Dr. Das is an employee of Alcon Laboratories, Inc. The Complete Angle Instrument scatterometer was developed by Dr. Stover at the Scatterworks, Inc. Neither of the other authors has a financial or proprietary interest in any method or material mentioned.


Assuntos
Ofuscação , Lentes Intraoculares , Óptica e Fotônica , Espalhamento de Radiação , Vacúolos , Resinas Acrílicas , Cadáver , Remoção de Dispositivo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Luz
15.
J Biol Res (Thessalon) ; 22(1): 10, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26361608

RESUMO

The present review attempted to emphasize on the microbiological quality of the commonly used cosmetics item by the majority of the Bangladeshi community. The abundance of contaminating microorganisms has been quantitatively discussed and the possible health risk has been focused upon usage of these items. Only a very few research efforts have been conducted on the cosmetic items in Bangladesh so far. The microbiological contamination aspects have been portrayed in this review using the information collected from a substantial number of cosmetic items which were earlier subjected to extensive microbiological and biochemical analyses. The prevalence of bacteria, fungi and the specific pathogenic microorganisms has been discussed based on research so far locally conducted on the finished items sold in markets, especially within the Dhaka metropolis. The laboratory scale experiments revealed the presence of enormous number of bacteria, actinomycetes and fungi within the commonly used cosmetics. Conversely, the anti-bacterial activity was noticed in some of the products which might be in favor of the user safety. The prevalence of pathogenic microorganisms in the cosmetic items certainly raises a substantial public health issue. The necessity of the routine microbiological testing of the commonly used cosmetic items as well as the legislative measures to mitigate the contamination problem is thus of great significance.

16.
J Cataract Refract Surg ; 39(5): 770-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23395325

RESUMO

PURPOSE: To develop a technique for measuring the forward light scattering of intraocular lenses (IOLs). SETTING: The Scatter Works, Tucson, Arizona, USA. DESIGN: Evaluation of diagnostic technique. METHODS: A scatterometer with laser sources of 488 nm and 633 nm was used to directly measure the forward-scattered light of IOLs. These sources illuminated balanced salt solution-immersed IOLs within a cylindrical wet cell. The wet cell was placed at the center of rotation of a goniometer arm. On the end of the arm was a detector that measured the amount of laser light scattered from the IOL as a function of incident-beam angle. The measurements provided a profile of the scatter distribution for regions outside the directly transmitted beam. Forward and back light scatter was measured in new and artificially aged IOLs. RESULTS: Forward light scatter was increased in artificially aged IOLs compared with that in new unaged IOLs. The artificially aged IOLs developed sub-wavelength-diameter water nanoglistenings in the bulk material just below the surface. The measured scatter profiles were consistent with these subsurface droplets, suggesting Rayleigh-type scatter in the aged IOLs. The amount of light scatter from nanoglistenings does not appear to be sufficient to impair vision. Although the severely aged IOLs showed increased scatter, the level of increase was within 1 standard deviation of what is found in the normal population. CONCLUSION: A technique was developed enabling quantification of forward-scattered and back-scattered light from IOLs.


Assuntos
Técnicas de Diagnóstico Oftalmológico , Lentes Intraoculares , Espalhamento de Radiação , Densitometria , Humanos , Luz
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