Methods contrast sensitivity. Medical search. Frequent questions

The contrast sensitivity was measured in mesopic and photopic background luminances, with glare (G) levels of 0-2 (G0, G1, and G2, respectively) and spatial frequencies at 1.5, 3, 6, 12, and 18 cycles per degree (cpd). (jkos.org)
However, there was no change in contrast sensitivity at any glare level at 12 and 18 cpd after PTK. (jkos.org)
Visual acuity, contrast sensitivity, glare sensitivity and kinetic visual fields were measured at each test session. (bmj.com)
Binocular contrast sensitivity function was measured with the Optec 6500 FACT contrast sensitivity chart at distance and at three lighting conditions (85 cd/m2 and 3 cd/m2 with and without glare) in 36 eyes of 18 patients implanted with the AcrySof ReSTOR aspheric SN6AD3 IOL and 40 eyes of 20 patients implanted with the Acri.LISA 366D IOL. (fernandez-vega.com)
ISRCTN13894787 ) were assessed using a range of psychophysical measures of visual function, including best corrected visual acuity (BCVA), letter contrast sensitivity (CS), mesopic and photopic CS, mesopic and photopic glare disability (GD), photostress recovery time (PRT), reading performance and subjective visual function, using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). (bmj.com)
Purpose: To determine whether contrast sensitivity (CS) can represent photophobia in intermittent exotropia (IXT) by comparingthe CS test with and without glare stimulus, and to analyze the factors of IXT affecting CS. (kyobobook.co.kr)
However, there are some concerns regarding the visual quality provided by MIOLs, such as glare, halos or reduced contrast sensitivity (CS). (scirp.org)

The accommodating group had better contrast sensitivity under photopic conditions at all spatial frequencies ( P ≤.04). (lww.com)
Both IOLs provided contrast sensitivity within the normal range in photopic conditions. (fernandez-vega.com)
The AcrySof ReSTOR SN6AD3 and Acri.LISA aspheric IOLs provided contrast sensitivity within normal range under photopic conditions and a reduction in contrast sensitivity under mesopic conditions, with no significant differences between the two brands. (fernandez-vega.com)
Contrast sensitivity measurements were performed under photopic conditions (85 cd/m 2 ) with the Visual Contrast Test Sensitivity 6500 chart, allowing for the evaluation of five spatial frequencies with sine wave grating charts: 1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree (cpd). (aboonline.org.br)

Contrast sensitivity increased after surgery in all spatial frequencies. (bvsalud.org)
Contrast sensitivity increased after posterior chamber phakic intraocular lens implantation (Staar ICL) in all spatial frequencies when compared to preoperative contrast sensitivity (best spectacle-corrected). (bvsalud.org)
Contrast detection thresholds for Gabor stimuli (SD, 0.75°) of four spatial frequencies (0.5, 1.0, 2.0, and 4.0 c/deg) were first measured at 10° eccentricity, both within and outside of visual field defects for participants with glaucoma. (brad.ac.uk)
Under low lighting conditions, a reduction in contrast sensitivity for both lenses, particularly at higher spatial frequencies, was noted. (fernandez-vega.com)
Was measured FSC for linear sine-wave grating stimuli with spatial frequencies of 0.25, 1.0, 2.0 and 8.0 cpd, using the forced-choice psychophysic method with two alternatives temporal. (bvsalud.org)
These results suggest that the process of development and maturation of the visual perception of contrast interacts differently with the mechanisms that process spatial frequencies. (bvsalud.org)

Major parameters were monocular and binocular uncorrected (UDVA) and corrected (CDVA) distance, uncorrected (UIVA) and distance corrected (DCIVA) intermediate (80 cm), and uncorrected (UNVA) and distance corrected (DCNVA) near (40 cm) visual acuities (UNVA), contrast sensitivity (CS), defocus curve as well as patient satisfaction and spectacle use. (scirp.org)

The change in contrast sensitivity after surgery was the best predictor of the improvements in driving performance in patients with cataract. (bmj.com)

All patients were able to perform both tests, and almost all patients showed moderate or profound deficits in contrast sensitivity (normal value, ~1.70 log units) despite near-normal visual acuity. (arvojournals.org)
and crash involvement is predicted by deficits in contrast sensitivity. (bmj.com)

For osteonecrosis of the femoral head, MRI has become the imaging modality of choice because of its high sensitivity and specificity. (medscape.com)
That finding contrasts with ELISAs that use crude Taenia antigens and have reduced sensitivity and specificity ( 10 , 11 ). (cdc.gov)
however, it has low sensitivity and specificity. (medscape.com)

To investigate contrast sensitivity (CS) in glaucoma patients with advanced visual field damage from glaucoma, and to evaluate the precision of two clinical CS tests. (arvojournals.org)
Contrast sensitivity should be routinely evaluated alongside visual acuity to monitor foveal visual function in patients with advanced glaucoma. (arvojournals.org)
Glaucoma raises contrast detection thresholds, but our natural visual environment is dominated by high contrast that may remain suprathreshold in early to moderate glaucoma. (brad.ac.uk)
This study investigates the effect of glaucoma on the apparent contrast of visible stimuli. (brad.ac.uk)
Despite decreased contrast sensitivity, people with glaucoma perceive the contrast of visible suprathreshold stimuli similarly to healthy controls. (brad.ac.uk)
Bham HA, Dewsbery SD and Denniss J (2020) Unaltered perception of suprathreshold contrast in early glaucoma despite sensitivity loss. (brad.ac.uk)
Afterwards, the best corrected ocular diseases, including optic neuritis and visual acuity was determined on a subjec- glaucoma, where contrast sensitivity can be tive basis. (who.int)

By exploiting the Bayesian foundation of the quick CSF method (Lesmes, Lu, Baek, & Albright, 2010), we developed and evaluated metrics for detecting CSF changes at both the individual and group levels. (adaptivesensorytech.com)

These results make it plausible to apply the method to monitor the progression of visual diseases or treatment effects on individual patients and greatly reduce the time, sample size, and costs in clinical trials at the group level. (adaptivesensorytech.com)
Supported in part by a grant from the Spanish Ministry of Health, Instituto Carlos III, Red Temática de Investigación Cooperativa en Salud Patología Ocular del Envejecimiento, Calidad Visual y Calidad de Vida, Subproyecto de Calidad Visual (RD07/0062). (lww.com)
Optical quality is a subjective construct that can only be described indirectly by objective metrics such as wavefront error measurements and visual quality metrics or functional data like visual acuity and contrast sensitivity. (hindawi.com)
Binocular visual acuity and contrast sensitivity at 2.5% contrast were also measured. (bmj.com)
The vision was blurred in all subjects and visual acuity and contrast sensitivity had decreased in three of the four subjects. (bmj.com)
Contrast sensitivity was tested with best spectacle-corrected visual acuity preoperatively and 3, 6, 12, 18, and 24 months postoperatively. (bvsalud.org)
Contrast sensitivity, the ability to distinguish the relative difference in luminance of an object from its surrounding or adjacent objects, is a useful measure of visual function. (jkos.org)
We compared the contrast sensitivity of GCD2 patients before and after phototherapeutic keratectomy (PTK) to evaluate the perioperative visual function in these patients. (jkos.org)
The visual acuity and contrast sensitivity were measured before and after PTK. (jkos.org)
Visual measures including visual acuity, contrast sensitivity and stereopsis were assessed and cognitive tests administered. (bmj.com)
Prior to assessing contrast sensitivity (CS) determine distance vision/visual acuity using the Snellen chart. (academy.org.uk)
and with MnB for executive function, cognitive flexibility, visuo-spatial construction ability, and visual contrast sensitivity. (cdc.gov)
Children with brain tumors can present visual impairments like decreased visual acuity and contrast sensitivity (CS), loss of color vision, and visual field loss such as hemianopias ( 1 - 5 ). (frontiersin.org)
These results suggest possible compensation for sensitivity loss in the visual system. (brad.ac.uk)
Comparison between the role of spatial and temporal contrast sensitivities in the association with reading may provide insight into how visual tasks (such as reading) are related to primary optical or neural (or both) effects. (amplifyeye.care)
Avaliação da sensibilidade ao contraste foi realizada sob condições fotópicas (85 cd/m2) com tabela Visual Contrast Test Sensitivity 6500, permitindo avaliação de cinco frequências espaciais medidas com redes senoidais: 1.5, 3.0, 6.0, 12.0 e 18.0 ciclos por grau de ângulo visual (cpd). (aboonline.org.br)
Kolkata, May 25: Visual parameters such as colour vision, depth perception and contrast sensitivity of drivers influence crash involvement rates in India, says a recent study which also has laid bare the absence of protocols and testing methods in the country to assess the visual capabilities of drivers during their licensing process. (sentinelassam.com)
HOAs such as spherical aberration and secondary astigmatism, however, can reduce contrast sensitivity, and coma and trefoil can reduce visual resolution. (crstodayeurope.com)
Visual acuity charts only measure the eases, history of previous ocular surgery high frequency component of the contrast or photocoagulation and systemic diseases sensitivity function and are markedly af- other than diabetes. (who.int)
The G2 and NEO can be equipped with an automated assessment of a patient's visual sensitivity to contrast. (micromedinc.com)

The tester records the results to produce a contrast sensitivity function (CSF) or curve. (academy.org.uk)
Therefore, the diabetes, mode of control and last blood contrast sensitivity function curve gives glucose level, checked in the past month. (who.int)

The low frequencies test sensitivity to very large objects, while on the other end, high frequencies measure sensitivity to very small objects. (academy.org.uk)

David has 15+ years experience in X-ray Fluorescence Microscopy and fast efficient scanning and XRF methods. (lu.se)
Chris is a world expert in X-ray microscopy and leads a research group focused on developing new methods in x-ray microscopy, and applying them to interesting problems in biology, environmental science, and materials science. (lu.se)
X-ray microscopy and micro-tomography (μCT) are valuable non-destructive examination methods in many disciplines such as bio-medical research, archaeometry, material science and paleontology. (lu.se)

Each row or circular grouping of patches tests at a specific spatial frequency (cycles per degree), which measures the observer's sensitivity to a particular object size. (academy.org.uk)

After surgery, contrast sensitivity and wavefront measurements as well as tilt and decentration measurements were performed. (hindawi.com)
Measurements were performed to determine PET stability under varying MR conditions using the following metrics: sensitivity, scatter fraction, contrast recovery, uniformity, count rate performance, and image quantitation. (snmjournals.org)

50% of the variance in contrast sensitivity. (arvojournals.org)
Representing continuous optimization variables by uniform distributions without variable interactions, variance based sensitivity analysis quantifies the contribution of the optimization variables for a possible improvement of the model responses. (wikipedia.org)
In contrast to local derivative based sensitivity methods, the variance based approach quantifies the contribution with respect to the defined variable ranges. (wikipedia.org)

Our results indicate that the contrast sensitivity rhythm is modulated by D4Rs via a signaling pathway that involves NPAS2-mediated circadian regulation of Adcy1 . (jneurosci.org)
Cataract surgery results in marked improvements in driving performance, which are related to concurrent improvements in contrast sensitivity. (bmj.com)
Also techniques and results of reducing speckle contrast by averaging multiple B-scans will be presented. (spie.org)
Following a mixed method approach in this pragmatic study of two cases, we collected quantitative and qualitative data on feasibility and potential effectiveness and compared the results pre- and post-treatment. (frontiersin.org)
The method has demonstrated remarkable sensitivity detecting as few as 10 target molecules and rapid results under one hour, using a compact, motionless system. (nanotech-now.com)
Based on the results, we introduced related basic definitions, some neurodegenerative diseases, methods of examining iron deposition in these diseases, and their advantages and disadvantages. (springeropen.com)
This observational-descriptive article explains the main pathological factors in neurodegenerative diseases and how they work and move step by step to diagnostic imaging methods for these pathological factors and their advantages/disadvantages by summarizing the results of different articles. (springeropen.com)

To evaluate contrast sensitivity after posterior chamber phakic intraocular lens (PIOL) implantation for the correction of high myopia . (bvsalud.org)
To evaluate contrast sensitivity in non-high-risk, treatment-naïve proliferative diabetic retinopathy patients treated with panretinal photocoagulation and intravitreal injections of ranibizumab) versus panretinal photocoagulation alone. (aboonline.org.br)
This Narrative Review article aims to evaluate the performance of QSM compared to other methods of assessing iron deposition in the clinical field. (springeropen.com)
QSM is a new and non-invasive method that works based on these changes to evaluate the values of iron accumulations. (springeropen.com)

Among the sampled drivers, colour vision, vertical field of vision, depth perception, contrast sensitivity, acuity and phoria were found to influence their crash involvement rates. (sentinelassam.com)
The chart luminance was regularly checked acuity and Cambridge low-contrast grating using a spot photometer. (who.int)

X-ray grating interferometry is an excellent technique for X-ray phase contrast imaging and X-ray wavefront sensing with applications in materials science, biology and medical diagnosis. (lu.se)

In eyes of patients with non-high-risk proliferative diabetic retinopathy, panretinal photocoagulation treatment with ranibizumab appears to cause less damage to contrast sensitivity compared with panretinal photocoagulation treatment alone. (aboonline.org.br)
Thus, our evaluation of contrast sensitivity may support the use of ranabizumab as an adjuvant to panretinal photocoagulation for the treatment of proliferative diabetic retinopathy. (aboonline.org.br)

Abnormal contrast sensitivity was ob- retinopathy, mild, moderate, severe, or very served in 27.1% of eyes with diabetic retin- severe non-proliferative diabetic retinopa- opathy, compared with 9.0% in unaffected thy (NPDR), early proliferative diabetic eyes. (who.int)

Four hour exposure to a TEA concentration of 3.0 mg/m3 seemed to cause no effects, whereas exposure to 6.5 mg/m3 for the same period caused blurred vision and a decrease in contrast sensitivity. (bmj.com)
The fluctuations decrease the contrast of the built 2D activity map and worsen sensitivity and resolution of the dynamic speckle method. (spie.org)

[ 28 ] EUS has been shown to be the most accurate preoperative method of localizing and detecting insulinomas. (medscape.com)

A number of studies have shown that aspherical IOLs perform better compared to conventional spherical ones in terms of contrast sensitivity (CS), particularly under mesopic conditions [ 2 , 3 ]. (hindawi.com)
Method: Prospective study including 150 patients with implantation of three IOLs: trifocal diffractive IOL AT LISA tri 839 MP (ATLISA, n = 50), trifocal diffractive IOL PhysIOL FineVision (FineVision, n = 50) and the extended range of vision IOL Tecnis Symfony ZRX00 (Symfony, n = 50). (scirp.org)

There is still controversy about the effec- correction of the refractive error, the con- tiveness of contrast sensitivity as a screen- trast sensitivity was evaluated with a Cam- ing tool for diabetic retinopathy [12-17]. (who.int)

There were no symptoms or decreases in contrast sensitivity after exposure to a TEA concentration of 3.0 mg/m3. (bmj.com)
The contrast decreases from one triplet to the next. (academy.org.uk)

A more user friendly approach is to score in terms of contrast percentage. (academy.org.uk)

The contrast sensitivity function (CSF) has shown promise as a functional vision endpoint for monitoring the changes in functional vision that accompany eye disease or its treatment. (adaptivesensorytech.com)
In optiSLang, random sampling methods are used to generate discrete samples of the joined probability density function of the given random variables. (wikipedia.org)
The aim of this study was to characterize the contrast sensitivity function (CSF) of adolescents and young adults. (bvsalud.org)
Assess for a variety of conditions using an advanced analysis of color vision function and detecting subtle changes missed by other methods, available on the G2 and NEO. (micromedinc.com)

The method also has the benefit that high sensitivity can be obtained with moderate absorption contrast for the spectral holes. (optica.org)

When the first postoperative examination was not considered, there were no statistically significant differences in contrast sensitivity values at different postoperative periods . (bvsalud.org)
The differences in coefficients of repeatability and reproducibility could be explained by the psychometrical differences between methods. (amplifyeye.care)
The contrast is represented by a numeric value named average gradient, and can be determined by density differences in two areas of a radiograph. (bvsalud.org)

The VCTS uses highly controlled advanced photographic and printing techniques to present a series of sine-wave gratings at carefully calibrated levels of contrast. (academy.org.uk)
The size of the sine-wave gratings, the contrast levels, and their tilt are all based on current vision science and empirical data. (academy.org.uk)
Among other requirements, the method depends on the availability of highly X-ray absorbing metallic gratings. (lu.se)

This includes also the evaluation of robustness, i.e. the sensitivity towards scatter of design variables or random fluctuations of parameters. (wikipedia.org)

We assessed the sensitivity of a slightly different combination of antigens representing the 3 families of proteins (GP50, T24H, and Ts18var3) used in the EITB assay in a traditional ELISA by using samples known to be EITB-positive or EITB-negative. (cdc.gov)
Rapid diagnostic tests for malaria have been developed that employ immunochromatographic methods based on the detection of malarial antigens present in peripheral blood. (cdc.gov)
In contrast, responses to antigens administered by a Mantoux-type procedure, in which a known quantity of a known concentration of a standardized antigen is deposited in the skin, may be more accurate indicators of a waning or increasing cellular hypersensitivity. (cdc.gov)

Contrast sensitivity comparison between AcrySof ReSTOR and Acri.LISA aspheric intraocular lenses. (fernandez-vega.com)

Usage of 2D optical sensors to capture sequences of correlated 2D speckle patterns allows for building a pointwise estimate of a given statistical measure which should give a quantitative high contrast detailed 2D map of the spatial distribution of activity across the object surface. (spie.org)
Laser speckle contrast imaging (LSCI) uses a 780 nm laser for illumination and a high-sensitivity image sensor. (lu.se)

A specialist eye centre in London has found that 56 per cent of those who underwent LASIK surgery had suffered loss of contrast sensitivity (the inability to distinguish objects in poor light). (healthy.net)

Based on these samples, which are evaluated by the solver similarly as in the sensitivity analysis, the statistical properties of the model responses as mean value, standard deviation, quantiles and higher order stochastic moments are estimated. (wikipedia.org)
SPSS, version 11.5 was used and contrast sensitivity were checked inde- for all statistical calculations. (who.int)

In GCD2 patients, the contrast sensitivity increased significantly after PTK. (jkos.org)

Although the sensitivity of these tests may be high, their use as quantitative tools for assessment of anergy is limited. (cdc.gov)

Brain pathological changes during neurodegenerative diseases and their identification methods: How does QSM perform in detecting this process? (springeropen.com)
From the final cases, articles were selected that provided more relevant and complete explanations about the relationship between iron and neurodegenerative diseases and its imaging methods. (springeropen.com)

This article aims to obtain sufficient information about the first brain changes in the early stages of cognitive disorders and their imaging methods and understand the QSM technique and its clinical applications. (springeropen.com)

Subsequently, the contrast of a central Gabor was matched to that of a peripheral Gabor with contrast fixed at two times or four times the detection threshold. (brad.ac.uk)
For reference stimuli at four times the detection contrast, matched contrast ratios were similar across all three groups (P = 0.58). (brad.ac.uk)
This new method, offering label-free detection could hasten the rollout of new diagnostic kits. (nanotech-now.com)

Each correct letter has a contrast threshold value of 0.05 log units however scoring in terms of log units is reserved for research. (academy.org.uk)

Determine the CS thresholds in terms of a contrast percentage under the following conditions. (academy.org.uk)

Our study demonstrates a circadian rhythm of contrast sensitivity that peaks during the daytime, and that its regulation involves interactions of D4Rs, the clock gene Npas2 , and the clock-controlled gene adenylyl cyclase 1 ( Adcy1 ) in a subset of retinal ganglion cells (RGCs). (jneurosci.org)
The aim of this study was to gain insight into the association between optical and neural components of contrast sensitivity (CS), operationalized as spatial CS (optical and neural) or temporal CS (solely neural), and reading speed in a clinical sample of participants with macular pathologies. (amplifyeye.care)
The typical method involves "scanning patients before contrast and at multiple phases after the administration of IV contrast," says Lawrence Chow, MD, lead author of the study. (mddionline.com)

Cataract surgery has evolved from a simple procedure of removing the opacified crystalline lens to a method that additionally aims to correct all refractive errors. (scirp.org)
Various treatment methods are available but extraocular muscle surgery remains the treatment of choice for permanent correction. (lu.se)
Furthermore, patients that are considered to have high risk of developing anterior segment ischemia are often not offered surgery at all or operated on with a suboptimal surgical method when a perfusion examination might show that standard procedures could be performed. (lu.se)

Contrast sensitivity after posterior chamber phakic intraocular lens implantation for high myopia. (bvsalud.org)

After exposure to TEA at 6.5 mg/m3 two subjects experienced symptoms, and contrast sensitivity had decreased in three of the four subjects. (bmj.com)
He says this typical method increases radiation exposure. (mddionline.com)
however, the authors commented on the greater sensitivity of blood than urine as a marker of indium exposure (in contrast to gallium and arsenic, the other metals evaluated). (who.int)
In contrast to many other MHP materials this scintillator shows good stability under continuous X-ray exposure and changing environmental conditions over extended time spans of several weeks. (lu.se)

Contrast recovery and uniformity were comparable for PET images acquired simultaneously with multiple MR conditions. (snmjournals.org)

2 ⇓ ⇓ ⇓ ⇓ ⇓ ⇓ ⇓ - 10 Although DSA is the criterion standard for follow-up imaging studies, TOF-MRA is also an accurate method for detecting recanalization in cerebral aneurysms treated with coil embolization. (ajnr.org)
The imaging method devised by Chow and his team, which included radiologists from both Stanford University and the VA Palo Alto Health Care System, identifies all pathologies present in the patients. (mddionline.com)
Quantitative susceptibility mapping (QSM) is one of the newest magnetic resonance imaging (MRI)-based methods for assessing iron accumulation in target areas. (springeropen.com)
This is aimed at researchers who are interested in this exciting method, but have little or no experience with X-ray Fluorescence imaging. (lu.se)
David will describe some of the latest XFM methods and techniques such as XANES imaging and advice on best sample preparation and data analysis methods. (lu.se)
To improve the image contrast for small and low-density samples, it is possible to introduce a propagation distance between sample and detector to perform propagation-based phase contrast imaging (PB-PCI). (lu.se)

This contrast mode relies on a sufficiently coherent illumination and is characterised by the appearance of an additional intensity modulations ('edge enhancement fringes') around interfaces in the image. (lu.se)

Methods Ninety nine drivers aged 55 years and older with bilateral cataract were recruited from three public hospitals in WA. (bmj.com)

The stronger association between temporal CS and reading speed is suggested to reflect a high sensitivity for neural integrity of temporal CS. (amplifyeye.care)

In 50 trials, the quick CSF method can detect a medium 0.30 log unit area under log CSF change with 94.0% accuracy at the individual observer level. (adaptivesensorytech.com)

In contrast, nucleic acid-based approaches offer greater ease of development, enhanced sensitivity, and inherent flexibility, according to the researchers. (nanotech-now.com)

Anatomy18

Organisms5

Diseases32

Chemicals and Drugs6

Analytical, Diagnostic and Therapeutic Techniques and Equipment44

Psychiatry and Psychology39

Phenomena and Processes32

Disciplines and Occupations3

Anthropology, Education, Sociology and Social Phenomena1

Technology, Industry, Agriculture1

Humanities1

Information Science2

Named Groups1

Health Care10

Geographicals1

Glare7

Photopic conditions4

Spatial frequencies6

Defocus curve1

Change in contrast sensitivity1

Deficits2

Specificity3

Glaucoma7

Evaluated metrics1

Visual20

Curve2

Test sensitivity1

Microscopy3

Cycles per degree1

Measurements2

Variance3

Results7

Evaluate4

Acuity2

Wavefront1

Photocoagulation2

Proliferative diabetic1

Decrease2

Preoperative1

IOLs2

Diabetic retinopathy1

Decreases2

Terms of contrast1

Function4

Moderate1

Differences3

Gratings3

Scatter1

Antigens3

Intraocular lenses1

Speckle2

Distinguish1

Statistical2

Significantly1

Assessment1

Diseases2

Cognitive1

Detection3

0.051

Thresholds1

Study3

Surgery3

Myopia1

Exposure4

Conditions1

Imaging6

Illumination1

Cataract1

Temporal1

Detect1

Flexibility1