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2.
Sci Rep ; 14(1): 461, 2024 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-38172170

RESUMEN

Exposure to air pollution is associated with many different health effects, especially cardiovascular and respiratory diseases. Additionally, highly significant links between exposure to air pollution and fertility, particularly male fertility was observed, however the studies regarding exposure to selected air pollutants and female fertility assessed by ovarian reserve are rare. Hence, the main aim of the study was to analyze relationship between exposure to ambient air pollution and ovarian reserve parameters among Polish women. The study population consisted of 511 women, who attended to infertility clinic because of diagnostic purposes. Participants filled in the questionnaire about social-demographic, lifestyle and health factors. Infertility specialists assessed ovarian parameters such as: antral follicle count (AFC) and concentration of hormones: Anti-Müllerian hormone (AMH), follicle stimulating hormone (FSH) and estradiol (E2). The air pollutants level (sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone, particulate matters) were obtained via National Environmental Protection Inspectorate database. Significant negative association between PM2,5 and AHM (p = 0.032) as well as AFC (p = 0.044) was observed. Moreover, SO2 concentrations decrease AFC (p = 0.038). The results also suggest that PM10, PM2.5, SO2 exposure on antral follicle count may be more pronounced among women with a female factor infertility diagnosis. Additionally, exposure to PM2.5 and NOx on AFC and AMH was stronger among older women (> 35 years of age). To conclude, the present study found that air pollution could lead to decrease in follicle antral count and Anti-Müllerian hormone level, especially exposure to PM2,5 and SO2 thus the evidence suggest negative impact to ovarian reserve.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Infertilidad Femenina , Reserva Ovárica , Femenino , Humanos , Masculino , Anciano , Hormona Antimülleriana , Infertilidad Femenina/etiología , Infertilidad Femenina/diagnóstico , Estradiol , Contaminación del Aire/efectos adversos , Contaminantes Atmosféricos/efectos adversos , Material Particulado
3.
Med Pr ; 74(5): 399-407, 2023 Dec 15.
Artículo en Polaco | MEDLINE | ID: mdl-38104340

RESUMEN

BACKGROUND: Central register of data on exposure to carcinogenic or mutagenic chemical substances, their mixtures, agents or technological processes (CRCR) conducted by Nofer Institute of Occupational Medicine (NIOM) enables monitoring of such agents occurrence in working environment in Poland. The NIOM conducts CRCR based on the provisions of the Regulation of the Minister of Health of 24 July 2012 on chemical substances, their mixtures, agents or technological processes with carcinogenic or mutagenic effects in the work environment. The work summarizes the information reported to CRCR in 2018-2021. MATERIAL AND METHODS: The data were extracted from CRCR, to which it was transferred by sanitary inspections. The data were extracted from CRCR. Data in this register is gathered based on employers' notifications to sanitary inspection. The study includes the number of reported agents (chemical substances and technological processes), the number of enterprises and the number of persons exposed to particular groups of agents (chemical substances, technological processes, ionizing radiation). RESULTS: The number of substances notified to the CRCR increases, from 382 reported substances in 2018 to 444 in 2021. Significant increase in the number of enterprises reporting technological processes (from 981 in 2018 to 5422 in 2021) and the number of exposed persons results from the law amendments extending the list of carcinogenic or mutagenic processes. CONCLUSIONS: The CRCR is a unique database on the occurrence and exposure to occupational carcinogens and mutagens, in which data from over 20 years has been collected. The increase in the number of reports to the register was mainly influenced by legislative changes regarding carcinogenic or mutagenic agents. Due to amount and complexity of data, they can be used for analysis in projects and programs aimed at raising awareness and reducing risk of occupational exposure to carcinogens and also during legislative works in Poland and in the EU. Med Pr Work Health Saf. 2023;74(5):399-407.


Asunto(s)
Carcinógenos , Exposición Profesional , Humanos , Carcinógenos/análisis , Mutágenos/toxicidad , Polonia/epidemiología , Exposición Profesional/análisis
4.
Environ Sci Pollut Res Int ; 30(6): 13974-13993, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36564686

RESUMEN

Widespread exposure to persistent pollutants can disrupt the bodies' natural endocrine functions and contribute to reproductive diseases like endometriosis. In this review, we focus at the relationship between endocrine-disrupting chemicals (EDCs), including metals and trace elements, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), poly-brominated diphenyl ethers (PBDEs), polychlorinated dibenzodioxin (PCDDs), polychlorinated dibenzofurans (PCDFs), and per- and polyfluoroalkyl substances (PFAS) exposure and risk of endometriosis. Relevant studies from the last 10 years by November 2022 were identified by searching Pubmed, Web of Science, and Scopus. The cohort and case-control studies that reported effect size with 95% confidence intervals (CIs) of EDC exposure and endometriosis were selected. Twenty three articles examining the relationship between endometriosis and exposure to persistent EDCs were considered. Most of the studies indicated association with exposure to persistent chemicals and development of endometriosis. The consistent results were found in case of lead, PCB-28, PCB-138, PCB-153, PCB-180, PCB-201, 1,2,3,7,8 - PeCDD, 2,3,4,7,8 - PeCDF and all described OCPs, showing the increased risk of endometriosis. These results support that exposure to certain EDCs, including OCPs, PCBs, PBBs, PBDEs, PFAS, and lead increase the risk of endometriosis.


Asunto(s)
Disruptores Endocrinos , Endometriosis , Contaminantes Ambientales , Fluorocarburos , Hidrocarburos Clorados , Plaguicidas , Bifenilos Policlorados , Femenino , Humanos , Bifenilos Policlorados/análisis , Contaminantes Ambientales/análisis , Endometriosis/inducido químicamente , Endometriosis/epidemiología , Éteres Difenilos Halogenados/análisis , Plaguicidas/análisis , Estudios de Casos y Controles
5.
Artículo en Inglés | MEDLINE | ID: mdl-35565013

RESUMEN

Endometriosis is a disease characterized by the presence of the uterine endometrium outside of its normal location. As the etiology of endometriosis is not well known and hormonal imbalance is central to disease pathogenesis, the potential contribution of exposure to endocrine-disrupting chemicals (EDCs) has been hypothesized in endometriosis. A systematic search of the literature was carried out to identify relevant studies using: PubMed, Scopus, Elsevier, Springer; EBSCO, and Web of Science. A total of 22 studies were considered. Most of the studies reviewed in this paper showed an association between exposure to BPA and phthalates and endometriosis. In the case of phthalate exposure, the reviewed studies found an association between the concentration of at least one phthalate metabolite and endometriosis. Only one study was performed to assess the exposure to parabens and a significant relationship with endometriosis was found. Additionally, only one study assessed the relationship of non-persistent pesticide exposure with endometriosis, observing a significant association between endometriosis and the urinary concentration of diazinon, chlorpyrifos, and chlorpyrifos-methyl. Studies struggled to provide a conclusion on the effect of exposure to benzophenones on endometriosis. Despite the numerous limitations of the results, the reviewed studies suggest that exposure to non-persistent endocrine disruptors, especially bisphenol A and phthalates may affect endometriosis. The results of the studies on exposure to parabens, benzophenones, and non-persistent insecticides are inconclusive.


Asunto(s)
Disruptores Endocrinos , Endometriosis , Contaminantes Ambientales , Ácidos Ftálicos , Benzofenonas , Disruptores Endocrinos/toxicidad , Endometriosis/inducido químicamente , Exposición a Riesgos Ambientales/efectos adversos , Exposición a Riesgos Ambientales/análisis , Contaminantes Ambientales/toxicidad , Femenino , Humanos , Parabenos/toxicidad , Ácidos Ftálicos/toxicidad
6.
J Clin Med ; 11(2)2022 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-35054073

RESUMEN

Aneurysmal subarachnoid haemorrhages (aSAH) account for 5% of strokes and continues to place a great burden on patients and their families. Cerebral vasospasm (CVS) is one of the main causes of death after aSAH, and is usually diagnosed between day 3 and 14 after bleeding. Its pathogenesis remains poorly understood. To verify whether plasma concentration of amino acids have prognostic value in predicting CVS, we analysed data from 35 patients after aSAH (median age 55 years, IQR 39-62; 20 females, 57.1%), and 37 healthy volunteers (median age 50 years, IQR 38-56; 19 females, 51.4%). Fasting peripheral blood samples were collected on postoperative day one and seven. High performance liquid chromatography-mass spectrometry (HPLC-MS) analysis was performed. The results showed that plasma from patients after aSAH featured a distinctive amino acids concentration which was presented in both principal component analysis and direct comparison. No significant differences were noted between postoperative day one and seven. A total of 18 patients from the study group (51.4%) developed CVS. Hydroxyproline (AUC = 0.7042, 95%CI 0.5259-0.8826, p = 0.0248) and phenylalanine (AUC = 0.6944, 95%CI 0.5119-0.877, p = 0.0368) presented significant CVS prediction potential. Combining the Hunt-Hess Scale and plasma levels of hydroxyproline and phenylalanine provided the model with the best predictive performance and the lowest leave-one-out cross-validation of performance error. Our results suggest that plasma amino acids may improve sensitivity and specificity of Hunt-Hess scale in predicting CVS.

7.
Amino Acids ; 53(1): 119-132, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33398522

RESUMEN

Glioblastoma (GB) is the most common primary brain tumour in adults. The lack of molecular biomarker, non-specific symptoms and fast growth rate often result in a significant delay in diagnosis. Despite multimodal treatment, the prognosis remains poor. Here, we verified the hypothesis that amino acids (AA) regulating the critical metabolic pathways necessary for maintenance, growth, reproduction, and immunity of an organism, may constitute a favourable target in GB biomarker research. We measured the plasma amino acids levels in 18 GB patients and 15 controls and performed the quantitative and qualitative metabolomic analysis of free AA applying high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). We present both the raw data and the results of our statistical analysis. The majority of AA were lowered in the study group in comparison to the control group. Five of these (arginine, glutamic acid, glutamine, glycine, and histidine) differed significantly (all p < 10-5 and AUC > 0.9). Plasma levels of leucine and phenylalanine decreased in the case of GB with lost alpha-thalassemia/mental retardation X-linked (ATRX) expression on immunohistochemistry (p = 0.003 and 0.045, respectively). We demonstrated for the first time that certain plasma-free AA levels of GB patients were significantly different from those in healthy volunteers. Target profiling of plasma-free AA, identified utilizing LC-QTOF-MS, may present prognostic value by indicating GB patients with lost ATRX expression. The on-going quest for glioma biomarkers still aims to determine the detailed metabolic profile and evaluate its impact on therapy and prognosis.


Asunto(s)
Aminoácidos/sangre , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Proteína Nuclear Ligada al Cromosoma X/metabolismo , Anciano , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/metabolismo , Neoplasias Encefálicas/sangre , Neoplasias Encefálicas/diagnóstico , Femenino , Glioblastoma/sangre , Glioblastoma/diagnóstico , Humanos , Masculino , Metabolómica , Persona de Mediana Edad , Pronóstico
8.
Biomolecules ; 10(11)2020 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-33228230

RESUMEN

Extracts from the defatted evening primrose (Oenothera paradoxa Hudziok) seeds are the source of a range of stable polyphenolic compounds, including ellagic acid, gallic acid, and catechin. Our studies evaluate, for the first time, the influence of evening primrose isopropanol extract (EPE) on malignant pleural mesothelioma (MPM) cells. MPM is rarely diagnosed, its high aggressiveness and frequently noted chemoresistance limit its treatment schemes and it is characterized by low prognostic features. Here, we demonstrate that EPE inhibited MPM growth in a dose-dependent manner in cells with increased invasion properties. Moreover, EPE treatment resulted in cell cycle arrest in the G2/M phase and increased apoptosis in invasive MPM cell lines. Additionally, EPE strongly limited invasion and MMP-7 secretion in MPM cancer cells. Our original data provide evidence about the potential anti-invasive effects of EPE in MPM therapy treatment.


Asunto(s)
Mesotelioma Maligno/patología , Oenothera biennis , Extractos Vegetales/farmacología , Pleura/efectos de los fármacos , Pleura/patología , Polifenoles/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Relación Dosis-Respuesta a Droga , Humanos , Mesotelioma Maligno/tratamiento farmacológico , Invasividad Neoplásica/patología , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/uso terapéutico , Polifenoles/aislamiento & purificación , Polifenoles/uso terapéutico , Semillas
9.
Beilstein J Org Chem ; 13: 451-494, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28382183

RESUMEN

This comprehensive review describes methods for the preparation of 1-indanones published in original and patent literature from 1926 to 2017. More than 100 synthetic methods utilizing carboxylic acids, esters, diesters, acid chlorides, ketones, alkynes, alcohols etc. as starting materials, have been performed. This review also covers the most important studies on the biological activity of 1-indanones and their derivatives which are potent antiviral, anti-inflammatory, analgesic, antimalarial, antibacterial and anticancer compounds. Moreover, they can be used in the treatment of neurodegenerative diseases and as effective insecticides, fungicides and herbicides.

10.
Mini Rev Med Chem ; 16(14): 1167-74, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27457212

RESUMEN

In recent years, metabolomics has become a necessary tool for understanding the impact of external and pathological factors on the operation of biological systems. The first reports of metabolomics date back to the 1970s, however, the area only began to develop dynamically at the beginning of this century and has proved effective only during the present decade. The five primary tools used in this form of analysis are NMR spectrometry, HPLC, TLC-UV, GC-MS and LC-MS/MS, with MS as the most universal approach, particularly when used together with chromatographic separation and NMR. Diabetes mellitus type 2 (T2DM) is a rapidly growing problem with global consequences. The metabolomic approach has been extensively applied to examining T2DM, insulin resistance and obesity, not only to assess the development of the disease, but also to discover its potential biomarkers. The presented review summarizes current studies on lipidomic and proteomic profiles in the context of different types of diabetes mellitus disease (T1DM, T2DM and GDM), as determined by chromatography-coupled mass spectrometry.


Asunto(s)
Diabetes Mellitus/metabolismo , Espectrometría de Masas/métodos , Metabolómica/métodos , Proteómica/métodos , Animales , Humanos , Metabolismo de los Lípidos , Lípidos/análisis , Proteínas/análisis , Proteínas/metabolismo
11.
ChemistryOpen ; 1(1): 33-8, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24551490

RESUMEN

Quaternary ammonium and phosphonium salts have been screened for their toxic effect on HeLa and K562 cancer cell lines, as well as on normal HUVEC cells. Tri-n-butyl-n-hexadecylphosphonium bromide, the first phosphonium salt with a halogen anion tested against HeLa cells, was 12 times more potent (IC50 <5 µm after 24 and 48 h) than the clinically used reference compound cisplatin and 17 times more potent than tri-n-hexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide, which, to the best of our knowledge, is the first phosphonium salt to be evaluated in HeLa cells. However, it was inactive against K562 cells (24 and 48 h). According to a caspase-3/7 assay, its toxicity has not been connected with the induction of apoptosis. In contrast, triphenylalkylphosphonium iodides with shorter C1-5 alkyl chains were inactive against HeLa cells but very active against K562 cells (IC50=6-10 µm after 48 h). Phosphonium cations with halide counterions proved to be more potent than those with (CF3SO2)2N(-) as the anion, as in the anticancer agent NSC 747251, or other anions in molecules with similar alkyl chain lengths. On the other hand, a series of ammonium salts containing a short methylthiomethyl or methoxymethyl side chain revealed low cytotoxicity (IC50 >500 µm after 24 and 48 h) against both HeLa and K562 cancer cell lines as well as normal HUVEC cells, showing that the nontoxic N(+)CH2YMe (Y=S, O) structural motif in ammonium salts could be suitable for further optimization and development, especially in transfection experiments.

12.
Eye Contact Lens ; 37(6): 342-7, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21876438

RESUMEN

OBJECTIVES: Evaluating precorneal tear film is one of important clinical measurements for assessing health of anterior eye. Contact lens wear is known to influence the quality of tear film. The aim was to evaluate the applicability of lateral shearing interferometry technique in the noninvasive assessment of the effects of contact lens replacement modality and its water content on tear film stability. METHODS: Sixteen regular soft contact lens wearers took place in the study. Lateral shearing interferometry measurements, in suppressed blinking conditions, were taken in the mornings and afternoons, after a minimum of 5 hours of lens wear for the daily lenses, and after 2 weeks and 1 month for the fortnightly and monthly lens replacement modalities, respectively. RESULTS: Significant differences (paired bootstrap-based Behrens-Fisher test, P < 0.05) in the tear film surface quality were found between all considered pairs of replacement modalities except for the daily and fortnightly lenses measured in the afternoon of the first day of wear. Significant worsening (paired bootstrap-based Behrens-Fisher test, P < 0.001) of tear film quality was found for the low water content materials. CONCLUSIONS: Lateral shearing interferometry is a powerful method for the noninvasive assessment of tear film surface quality on soft contact lenses that may find, in future, its use in the clinical assessment of anterior eye's health.


Asunto(s)
Lentes de Contacto Hidrofílicos , Interferometría/métodos , Lágrimas/química , Adolescente , Adulto , Femenino , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato , Interferometría/normas , Masculino , Siliconas , Lágrimas/fisiología , Adulto Joven
13.
Invest Ophthalmol Vis Sci ; 52(2): 751-6, 2011 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-20881295

RESUMEN

PURPOSE: To measure tear film surface quality in healthy and dry eye subjects using three noninvasive techniques of tear film quality assessment and to establish the ability of these noninvasive techniques to predict dry eye. METHODS: Thirty-four subjects participated in the study and were classified as dry eye or normal, based on standard clinical assessments. Three noninvasive techniques were applied for measurement of tear film surface quality: dynamic-area high-speed videokeratoscopy (HSV), wavefront sensing (DWS), and lateral shearing interferometry (LSI). The measurements were performed in both natural (NBC) and suppressed (SBC) blinking conditions. RESULTS: To investigate the capability of each method to discriminate dry eye subjects from normal subjects, the receiver operating curve (ROC) was calculated and then the area under the curve (AUC) was extracted. The best result was obtained for the LSI technique (AUC = 0.80 in SBC and AUC = 0.73 in NBC), which was followed by HSV (AUC = 0.72 in SBC and AUC = 0.71 in NBC). The best result for DWS was an AUC of 0.64 obtained for changes in vertical coma in SBC, whereas for NBC, the results were poorer. CONCLUSIONS: Noninvasive techniques of tear film surface assessment can be used for predicting dry eye, and such an assay can be achieved in NBC as well as SBC. In this study, LSI showed the best detection performance, closely followed by the dynamic-area HSV. The DWS technique was less powerful, particularly in NBC.


Asunto(s)
Técnicas de Diagnóstico Oftalmológico , Síndromes de Ojo Seco/diagnóstico , Lágrimas/fisiología , Aberrometría , Adulto , Anciano , Parpadeo/fisiología , Síndromes de Ojo Seco/metabolismo , Femenino , Fluoresceína/metabolismo , Humanos , Interferometría , Colorantes Verde de Lisamina/metabolismo , Masculino , Persona de Mediana Edad , Curva ROC , Adulto Joven
14.
J Biomed Opt ; 15(3): 037005, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20615034

RESUMEN

There are several noninvasive techniques for assessing the kinetics of tear film, but no comparative studies have been conducted to evaluate their efficacies. Our aim is to test and compare techniques based on high-speed videokeratoscopy (HSV), dynamic wavefront sensing (DWS), and lateral shearing interferometry (LSI). Algorithms are developed to estimate the tear film build-up time T(BLD), and the average tear film surface quality in the stable phase of the interblink interval TFSQ(Av). Moderate but significant correlations are found between T(BLD) measured with LSI and DWS based on vertical coma (Pearson's r(2)=0.34, p<0.01) and higher order rms (r(2)=0.31, p<0.01), as well as between TFSQ(Av) measured with LSI and HSV (r(2)=0.35, p<0.01), and between LSI and DWS based on the rms fit error (r(2)=0.40, p<0.01). No significant correlation is found between HSV and DWS. All three techniques estimate tear film build-up time to be below 2.5 sec, and they achieve a remarkably close median value of 0.7 sec. HSV appears to be the most precise method for measuring tear film surface quality. LSI appears to be the most sensitive method for analyzing tear film build-up.


Asunto(s)
Algoritmos , Topografía de la Córnea/métodos , Interferometría/métodos , Lágrimas/fisiología , Adulto , Análisis de Varianza , Parpadeo , Distribución de Chi-Cuadrado , Córnea/fisiología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Propiedades de Superficie
15.
Optom Vis Sci ; 87(7): 513-7, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20473236

RESUMEN

PURPOSE: To date, there have been no measuring techniques available that could clearly identify all phases of tear film surface kinetics in one interblink interval. METHODS: Using a series of cases, we show that lateral shearing interferometry equipped with a set of robust parameter estimation techniques is able to characterize up to five different phases of tear film surface kinetics that include: (i) initial fast tear film build-up phase, (ii) further slower tear film build-up phase, (iii) tear film stability, (iv) tear film thinning, and (v), after a detected break-up, subsequent tear film deterioration. RESULTS: Several representative examples are given for estimating tear film surface kinetics in measurements in which the subjects were asked to blink and keep their eyes open as long as they could. CONCLUSIONS: Lateral shearing interferometry is a noninvasive technique that provides means for temporal characterization of tear film surface kinetics and the opportunity for the analysis of the two-step tear film build-up process.


Asunto(s)
Interferometría/métodos , Lágrimas/metabolismo , Adulto , Anciano , Femenino , Humanos , Cinética , Masculino , Factores de Tiempo , Adulto Joven
16.
Ophthalmic Physiol Opt ; 29(3): 211-8, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19422551

RESUMEN

The lateral shearing interferometer was applied to the in vivo dynamic investigation of the external surface of the pre-corneal tear film after an eye blink. Sequences of interferograms were recorded at a sampling frequency of 25 Hz. Immediately after every eye blink, a bright pattern was observed under the interference fringes. This disappeared after a short time interval (around 0.5-2 s): smooth interference fringes were then observed, corresponding to the creation of a smooth anterior optical surface over the cornea. The purpose of this study is to describe in detail the kinetics of pre-corneal tear film stability and to propose quantitative measures of the stabilisation process in healthy eyes during the 3 s period after a blink. Two methods of quantitative assessment of the tear film build-up time are presented. The first is based upon the evaluation of the inhomogeneity of the background of the interferogram; the second evaluates the orientation of the structure of the background by the analysis of the zero order of the Fast Fourier Transform (FFT) spectrum. The quasi-vertically oriented bright line patterns observed in interferograms immediately after a blink and the mirror-symmetry of their tilts for right and left eyes indicate that the pattern is related to the wiping movements of the upper eyelids during the eye blink.


Asunto(s)
Análisis de Fourier , Lágrimas/fisiología , Humanos , Interferometría/métodos , Lágrimas/metabolismo , Factores de Tiempo
17.
J Biomed Opt ; 14(6): 064029, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20059267

RESUMEN

A lateral shearing interferometer was used to examine the smoothness of the tear film. The information about the distribution and stability of the precorneal tear film is carried out by the wavefront reflected from the surface of tears and coded in interference fringes. Smooth and regular fringes indicate a smooth tear film surface. On corneae after laser in situ keratomileusis (LASIK) or radial keratotomy (RK) surgery, the interference fringes are seldom regular. The fringes are bent on bright lines, which are interpreted as tear film breakups. The high-intensity pattern seems to appear in similar location on the corneal surface after refractive surgery. Our purpose was to extract information about the pattern existing under the interference fringes and calculate its shape reproducibility over time and following eye blinks. A low-pass filter was applied and correlation coefficient was calculated to compare a selected fragment of the template image to each of the following frames in the recorded sequence. High values of the correlation coefficient suggest that irregularities of the corneal epithelium might influence tear film instability and that tear film breakup may be associated with local irregularities of the corneal topography created after the LASIK and RK surgeries.


Asunto(s)
Córnea/fisiología , Procesamiento de Imagen Asistido por Computador/métodos , Interferometría/métodos , Queratomileusis por Láser In Situ , Lágrimas/fisiología , Adulto , Córnea/cirugía , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
18.
J Biomed Opt ; 14(6): 064039, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20059277

RESUMEN

Interferometry is a sensitive technique for recording tear film surface irregularities in a noninvasive manner. At the same time, the technique is hindered by natural eye movements resulting in measurement noise. Estimating tear film surface quality from interferograms can be reduced to a spatial-average-localized weighted estimate of the first harmonic of the interference fringes. However, previously reported estimation techniques proved to perform poorly in cases where the pattern fringes were significantly disturbed. This can occur in cases of measuring tear film surface quality on a contact lens on the eye or in a dry eye. We present a new estimation technique for extracting the first harmonic from the interference fringes that combines the traditional spectral estimation techniques with morphological image processing techniques. The proposed technique proves to be more robust to changes in interference fringes caused by natural eye movements and the degree of dryness of the contact lens and corneal surfaces than its predecessors, resulting in tear film surface quality estimates that are less noisy.


Asunto(s)
Interferometría/métodos , Lágrimas/fisiología , Lentes de Contacto , Síndromes de Ojo Seco/fisiopatología , Análisis de Fourier , Humanos
19.
Acta Ophthalmol Scand ; 85(2): 202-8, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17305735

RESUMEN

PURPOSE: This study describes a non-invasive method for the in vivo assessment of precorneal tear film stability. METHODS: A lateral shearing interferometer (LSI) is used for the measurement. The interference fringes obtained from the tear film layer are analysed using the fast Fourier transform (FFT) technique. The method is based on evaluating the degree of fringe disturbance by calculation of the second momentum of Fourier spectra on the interferogram pattern. RESULTS: This method points to the occurrence of dynamic changes in the tear film surface over time. We propose four different parameters. One of them is presented here. The less smooth the tear film, the more disturbed the interference fringes and the higher the value of the calculation parameters. Clear differences were discerned between tear film quality in healthy eyes, dry eyes and eyes with various contact lenses. The benefits of artificial tears used by patients with dry eye or contact lenses were also noted. Examination of dry eyes before and after applying fluorescein revealed significant differences in tear film stability. CONCLUSIONS: Lateral shearing interferometry is a suitable method for assessing the stability of the tear film on the cornea and on contact lenses. Evident differences can be demonstrated in tear film quality between normal eyes and dry eyes or eyes with soft contact lenses.


Asunto(s)
Lentes de Contacto Hidrofílicos , Córnea/metabolismo , Técnicas de Diagnóstico Oftalmológico , Síndromes de Ojo Seco/metabolismo , Interferometría/métodos , Lágrimas/metabolismo , Síndromes de Ojo Seco/tratamiento farmacológico , Humanos , Interpretación de Imagen Asistida por Computador , Luz , Soluciones Oftálmicas/uso terapéutico
20.
J Biomed Opt ; 11(3): 34028, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16822077

RESUMEN

Tear film stability plays an important role in the quality of vision. We present an interferometric method for assessing the stability of precorneal tear film in real time. A lateral shearing technique is applied as a noninvasive and sensitive method for investigating tear film stability and the smoothness of the tear film surface by quantitative evaluation of the interference fringe pattern. The evaporation of tears and the appearance of tear film break-up between blinks cause changes in the fringe geometry. For quantitative assessment of the fringe smoothness and consequently of the tear film structure, the fast Fourier transform (FFT) is applied. Four parameters are used to quantitatively estimate dynamic changes in the tear film stability of the cornea 20 s after the eye blink. Examples of examined interferograms recorded in patients with healthy eyes, patients suffering from dry-eye syndrome, and patients wearing contact lenses are given. Significant differences between the stability of the tear film in the healthy eye and that in the dry eye and the eye with a contact lens are observed. The favorable influence of artificial tears applied in patients with dry-eye syndrome or contact lenses is also discussed.


Asunto(s)
Síndromes de Ojo Seco/diagnóstico , Síndromes de Ojo Seco/fisiopatología , Interferometría/instrumentación , Enfermedades del Aparato Lagrimal/diagnóstico , Enfermedades del Aparato Lagrimal/fisiopatología , Refractometría/instrumentación , Lágrimas/química , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Interferometría/métodos , Cinética , Refractometría/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
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