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Saudi Journal of Ophthalmology :... 2022Aqueous flare and cells are inflammatory parameters of anterior chamber inflammation resulting from disruption of the blood-ocular barrier. The ocular inflammation...
Aqueous flare and cells are inflammatory parameters of anterior chamber inflammation resulting from disruption of the blood-ocular barrier. The ocular inflammation related to anterior chamber cells and flare is assessed by conventional clinical grading systems through using the slit-lamp examination. However, a more quantitative and objective assessment is needed for more precise and reproducible inflammatory assessment in uveitis. Laser flare photometer (LFP) was introduced as a noninvasive, objective, and quantitative evaluation of aqueous flare intensity and number of cells in the anterior chamber with good accuracy and repeatability. The success of LFP allowed clinicians to further evaluate the pathophysiology of intra-ocular inflammation and to incorporate LFP measurements to their routine clinical practice for diagnosis, management, and treatment of uveitis cases. In this review, we will discuss the importance of clinical utilization of LFP and the correlation between LFP and clinical grading systems along with some technical aspects. Furthermore, we will give a literature summary on the current applications of LFP in clinical practice of cases which present with various types of uveitis and diverse ocular conditions with or without inflammation.
PubMed: 36618569
DOI: 10.4103/sjopt.sjopt_119_22 -
Japanese Journal of Ophthalmology Jan 2017A slit-lamp examination is an indispensable and essential clinical evaluation method in ophthalmology, but, it is qualitative subjective. To complement its weaknesses in... (Review)
Review
A slit-lamp examination is an indispensable and essential clinical evaluation method in ophthalmology, but, it is qualitative subjective. To complement its weaknesses in making a quantitative evaluation of flare intensity and number of cells in the aqueous humor in the eye, we invented the laser flare-cell photometer in 1988. The instrument enables a non-invasive quantitative evaluation of flare intensity and number of cells in the aqueous with good accuracy and repeatability as well as maneuverability equal to slit-lamp microscopy. The instrument can elucidate the pathophysiology in the blood-aqueous barrier (BAB) function in a variety of ocular disorders. The accuracy of the instrument makes it possible to investigate not only the pathophysiology of intraocular disorders but also the effects of various drugs and surgical procedures in BAB. The instrument does not only lighten the burden on patients in clinical examinations and study but it also helps minimize the sacrifice of experimental animals and improves the reliability of the results by minimizing inter-individual variations through its good repeatability. Here I shall relate how the instrument has been applied to clinical and basic studies in ophthalmology and what novel knowledge its application contributed to pathophysiology in ophthalmology.
Topics: Animals; Aqueous Humor; Humans; Lasers; Ophthalmology; Photometry; Reproducibility of Results
PubMed: 27888376
DOI: 10.1007/s10384-016-0488-3 -
Diagnostics (Basel, Switzerland) Jan 2023This article systematizes available data from the literature on biliary gastritis (BG) in order to increase the awareness of specialists about the latest possibilities... (Review)
Review
This article systematizes available data from the literature on biliary gastritis (BG) in order to increase the awareness of specialists about the latest possibilities for diagnosing the disease. BG occurs as a result of pathological duodenogastric reflux. In patients with a preserved duodenogastric junction, the dominant factor is represented by motor disorders of the upper digestive tract (primary biliary gastritis), while in patients recovering from surgical interventions it is represented by structural changes (secondary biliary gastritis). Progressive BG can lead to atrophy of the gastric mucosa, intestinal metaplasia, epithelial dysplasia, and eventually to gastric cancer. Diagnostic methods for BG are carried out to identify risk factors, exclude alarm symptoms and identify persistent motor disorders and pathological reflux (24 h pH-impedancemetry, hepatobiliary scintigraphy, 24 h monitoring of bilirubin content in the reflux using a Bilitec 2000 photometer), as well as to diagnose gastritis itself (esophagogastroduodenoscopy, morphological gastrobiopsy examination). The diagnosis of BG should be based on a multidisciplinary approach that combines a thorough analysis of a patient's complaints, an anamnesis of the disease, and the results of endoscopic and histological research methods.
PubMed: 36672996
DOI: 10.3390/diagnostics13020186 -
The Analyst May 2021During the past few decades, there has been a growing trend towards the use of smartphone-based analysis systems. This is mainly due to its ubiquity, its increasing... (Review)
Review
During the past few decades, there has been a growing trend towards the use of smartphone-based analysis systems. This is mainly due to its ubiquity, its increasing computing capacity, its relatively low cost and the ability to acquire and process data at the same time. Furthermore, there are many sensors integrated into a smartphone, for example a complementary metal-oxide semiconductor (CMOS) sensor. A CMOS sensor enables optical analysis for example by using it as a colorimeter, photometer or spectrometer. This review explores the current state-of-the-art smartphone-based optical analysis systems in various areas of application. It is organized into three sections, each of which investigates one class of smartphone-based devices: (i) smartphone-based colorimeters (ii) smartphone-based photo- and spectrometers and (iii) smartphone-based fluorimeters.
PubMed: 33949421
DOI: 10.1039/d1an00025j -
Ophthalmic & Physiological Optics : the... Sep 2021To compare real-world measures of illumination obtained with the Actiwatch-2 and Clouclip-M2 with 'gold standard' photometry measures and to evaluate the ability of...
PURPOSE
To compare real-world measures of illumination obtained with the Actiwatch-2 and Clouclip-M2 with 'gold standard' photometry measures and to evaluate the ability of Actiwatch-2 to correctly identify photometer-defined conditions: scotopic (≤0.01 lux), mesopic (0.02-3 lux), indoor photopic (>3-1,000 lux) and outdoor photopic (>1,000 lux); and Clouclip to correctly identify photometer-defined conditions within its operating range (>1 lux). Inter-device reliability of Clouclip for illumination and viewing distance measures was also investigated.
METHODS
A Hagner-S2 photometer was used as reference. Measures of illumination were obtained from a range of real-world conditions. To investigate inter-device reliability, five Clouclips were simultaneously exposed to varied light conditions and object distances.
RESULTS
Strong correlations existed between illumination measured with the photometer and both Actiwatch-2 (ρ = 0.99, p < 0.0001) and Clouclip (ρ = 0.99, p < 0.0001). However, both devices underestimated illumination compared to the photometer; disparity increased with increasing illumination and was greater for Actiwatch-2 than Clouclip measures. Actiwatch-2 successfully categorised illumination level (scotopic, mesopic, indoor and outdoor photopic) in 71.2% of cases. Clouclip successfully categorised illumination levels as scotopic/mesopic (≤3 lux) and indoor and outdoor photopic in 100% of cases. Mean differences and limits of agreement (LOA) were 430.92 ± 1,828.74 and 79.35 ± 407.33 lux, between the photometer and Actiwatch-2 and photometer and Clouclip, respectively. The Intra-class Correlation Coefficients for illumination and viewing distance measured with five Clouclips were 0.85 and 0.96, respectively.
CONCLUSION
These data illustrate that different Clouclip devices produce comparable measures of viewing distance and illumination in real-world settings. Both Actiwatch-2 and Clouclip underestimate illumination in the field compared to gold standard photometer measures. The disparity increases at higher levels of illumination and the discrepancy was greater for Actiwatch-2 measures. For researchers interested in categorising light exposure, Clouclip classifies illumination levels >2 lux more accurately than Actiwatch-2 but cannot discriminate between scotopic and low mesopic light.
Topics: Color Vision; Humans; Lighting; Reproducibility of Results
PubMed: 34387902
DOI: 10.1111/opo.12860 -
Science (New York, N.Y.) Jun 2023Understanding the causes and potential mitigations of light pollution requires measuring and monitoring artificial light at night (ALAN). We review how ALAN is measured,... (Review)
Review
Understanding the causes and potential mitigations of light pollution requires measuring and monitoring artificial light at night (ALAN). We review how ALAN is measured, both from the ground and through remote sensing by satellites in Earth orbit. A variety of techniques are described, including single-channel photometers, all-sky cameras, and drones. Spectroscopic differences between light sources can be used to determine which are most responsible for light pollution, but they complicate the interpretation of photometric data. The variability of Earth's atmosphere leads to difficulty in comparisons between datasets. Theoretical models provide complementary information to calibrate experiments and interpret their results. Here, we identify several shortcomings and challenges in current approaches to measuring light pollution and suggest ways forward.
Topics: Atmosphere; Earth, Planet; Light Pollution; Models, Theoretical; Environmental Monitoring; Remote Sensing Technology
PubMed: 37319204
DOI: 10.1126/science.adg0473 -
Scientific Reports Oct 2022The growing concern about the negative impact of artificial light at night on biodiversity and human health increases the need of defining a general indicator that could...
The growing concern about the negative impact of artificial light at night on biodiversity and human health increases the need of defining a general indicator that could be used for characterizing light pollution as well as performing both spatial and temporal comparisons. In this paper, we show that the traditional indicators based on direct numerical measurements of sky brightness suffer from significant limitation due to calibration bias and lack of reproducibility. Furthermore, these measures are most often performed in periods of clear sky. They do not reflect the wide variety of meteorological conditions that can produce highly inhomogeneous levels of light pollution on a given site. To overcome these issues, we propose a statistical indicator called NSB Dispersion Ratio. This indicator is derived from a statistically significant number of individual night sky brightness measurements, under various meteorological conditions. It is independent of any absolute photometer calibration. It only requires on-time precise corrections of the contribution of natural light sources such as the Galactic plane.
Topics: Calibration; Humans; Light Pollution; Reproducibility of Results
PubMed: 36220856
DOI: 10.1038/s41598-022-21460-5 -
Current Research in Biotechnology 2022We catalog and summarize evidence of the analytical performance of portable quantitative and semi-quantitative devices for the assessment of vitamin A status and vitamin... (Review)
Review
BACKGROUND
We catalog and summarize evidence of the analytical performance of portable quantitative and semi-quantitative devices for the assessment of vitamin A status and vitamin A deficiency (VAD) in various biological samples-including whole blood, plasma, serum, and milk-in addition to VAD determination by functional indicators such as pupillary response.
METHODS
We searched the literature for published research articles, patents, and information from manufacturers of mobile devices, particularly those appropriate for low-resource settings. The included devices were required to be portable (lightweight and ideally not needing a power outlet) and to measure vitamin A as well as define VAD. Eligible studies compared a portable device to a reference standard of high-performance liquid chromatography for blood and milk, or a Goldmann-Weekers dark adaptometer for eyes/vision. Where available, identified devices were compared with reference methods across several performance criteria. When possible, we compared the device's performance reported in published studies against the stated performance criteria from the manufacturers' websites.
RESULTS
We catalogued 25 portable devices for measuring vitamin A and/or VAD via biological samples. We also identified 18 comparison studies (plus associated reports) assessing nine methods: the iCheck Fluoro, iCheck Carotene, CRAFTi, Tidbit with or without the HYPER filtration system, custom field-friendly immunoassays, and microfluidic assays for blood; the iCheck Fluoro and iCheck Carotene for milk; and the Scotopic Sensitivity Tester-1 for eye function.
CONCLUSIONS
The iCheck Fluoro and iCheck Carotene are commercially available for use and are acceptable for measuring vitamin A in blood and milk samples, according to the available validation data. Many of the other identified devices, including other portable fluorometers, photometers, immunoassays, microfluidics-based devices, and dark adaptometers, were proofs of concept and not yet commercially available. Furthermore, none of these other devices included manufacturer-described device performance criteria to compare with descriptions from experimental studies. Several gaps remain, including studies comparing the other portable devices against a reference standard, particularly for functional indicators of vitamin A status/deficiency; available manufacturer-reported device performance criteria against which to compare future results of investigations; and more comprehensive reporting of validation metrics including sensitivity, specificity, precision, and Bland-Altman analysis.
PubMed: 36033130
DOI: 10.1016/j.crbiot.2022.04.003 -
Journal Francais D'ophtalmologie Sep 2021To study the effect of ocular inflammation in active uveitis on the corneal endothelium.
PURPOSE
To study the effect of ocular inflammation in active uveitis on the corneal endothelium.
MATERIALS AND METHODS
This is a prospective cross-sectional study involving 63 eyes of 38 patients with active newly-diagnosed uveitis. Eighty-four eyes of 42 non-uveitic subjects served as a control group. All patients underwent detailed ophthalmic examination, laser flare photometry, and non-contact specular microscopy. Eyes with uveitis had a follow-up visit at one month after initiation of treatment, including laser flare photometry and specular microscopy.
RESULTS
The mean age of the active uveitis patients was 33 (range: 9-67 years) with 21 men (55%) and 17 women (45%). For the uveitis patients at baseline, the mean flare value was 32ph/ms (range: 15-100ph/ms) with flare photometry value ≥50ph/ms in 13 eyes (21%) and<50ph/ms in 50 eyes (79%). At baseline, cell density (CD) of the uveitis patients was similar to CD in control eyes (p꞊0.16). The percent of hexagonality was significantly lower (p<0.0001), and the coefficient of variance (CV) (p<0.0001) and central corneal thickness (CCT) (p<0.0001) were significantly higher than in the control group. After one month, there was a significant decrease in flare photometry values (p<0.0001), with a mean flare value of 14.5ph/ms (range: 4-60ph/ms). In the active uveitis group, the overall results of specular microscopy did not significantly vary between the initial examination and the 1-month examination. For eyes with flare photometry value ≥50ph/ms at baseline, CD and hexagonal cell count significantly increased on the 1-month examination (p꞊0.01 and p꞊0.02 respectively), while CV and CCT decreased significantly at the one-month follow-up visit (p꞊0.007/p꞊0.03 respectively). For eyes with flare photometry value at baseline <50ph/ms, there was no significant differences in specular microscopy results between the initial examination and the 1-month examination.
CONCLUSIONS
In eyes with newly-diagnosed uveitis and active anterior chamber inflammation, specular microscopy shows transient qualitative abnormalities of the corneal endothelium that depend on the severity of the anterior chamber inflammation as measured by the laser flare meter.
Topics: Adolescent; Adult; Aged; Child; Cross-Sectional Studies; Endothelium, Corneal; Female; Humans; Male; Microscopy; Middle Aged; Prospective Studies; Uveitis; Uveitis, Anterior; Young Adult
PubMed: 34172297
DOI: 10.1016/j.jfo.2020.10.024 -
Journal of Aerosol Medicine and... Dec 2020The method section of this chapter on regional lung deposition highlights a nonradioactive method to measure regional deposition, which uses a photometer to quantify...
The method section of this chapter on regional lung deposition highlights a nonradioactive method to measure regional deposition, which uses a photometer to quantify inhaled and exhaled particles and in that way is able to estimate the lung region from which the particles are exhaled and to what amount. The radioactive methods cover the measurement of clearance of the deposited particles as well as different imaging techniques to determine regional deposition. The result section reviews trials in human subjects. It also addresses different parameters that influence the regional deposition in the lungs: particle size, inhalation maneuver, carrier gas, disease, and inhalation device. All of these factors can affect regional deposition significantly. By choosing specific values of these parameters, it should be feasible to target different regions of the lungs for the therapy of different diseases.
Topics: Aerosols; Humans; Lung; Particle Size; Positron-Emission Tomography; Tomography, Emission-Computed, Single-Photon
PubMed: 33021414
DOI: 10.1089/jamp.2020.29032.sh