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In this study, we investigated the integration of an NdFeB N35 permanent magnet into an electromagnetic chuck to maintain its magnetic force continuously. By energizing or deenergizing the coil wrapped around the chuck, the surface magnetic force was increased or decreased, achieving either stronger adhesion or easy detachment of the attached object, respectively. ANSYS Maxwell software was utilized to simulate the initial model, the results of which were then compared with physical measurements. Keeping the external dimensions unchanged, the yoke's dimensions were used as the parameters to analyze the effect of changes in dimensions at different positions on the electromagnetic chuck's surface adhesion force. Differences between simulated and measured results for the initial model after energizing the electromagnetic chuck were within 6%. Among the simulations with different parameters, changes in the thickness of the outer frame base and inner diameter did not significantly affect the magnetic flux on the surface of the electromagnetic chuck. Therefore, these results were not shown in this study. Alterations in the yoke's dimensions affected the relative position and size of the coil or created new magnetic flux paths. A distance of less than 1 mm between the coil and the chuck surface significantly affected the surface magnetic flux density. [ABSTRACT FROM AUTHOR]

In this study, we conducted stress and strain analyses on the eyeball under pressure using the finite element simulation software Ansys. The eyeball model was constructed using SolidWorks, and additionally, it simulates a contact-type tonometer, applying pressure to the eyeball through probe force variations and calculating the pressure changes inside the eyeball. Initially, the cornea, sclera, ciliary body, suspensory ligaments, aqueous humor, and vitreous humor were combined using SolidWorks. Subsequently, the model was imported into Ansys for meshing, boundary setting, and simulation calculation. Finally, the analysis results were extracted using the Ansys postprocessor and the simulated data were validated against actual measurement data to ensure accuracy. Material properties necessary for the eyeball under pressure analyses were configured, with the Mooney-Rivlin hyperelastic material being selected. During compression, the cornea and sclera primarily absorbed the concentrated load after compression. Pressure was applied using a probe to observe variations in stress and strain concerning the applied force and intraocular pressure. Three probe materials (rubber, titanium alloy, and glass) were chosen for comparative simulation analyses. [ABSTRACT FROM AUTHOR]

Purpose: Simulation techniques are used in healthcare education to support the development of clinical skills. The aim of this study was to investigate the perceived value of a tonometry model eye (TME) when used in teaching and learning the clinical skill of Goldmann applanation tonometry (GAT) in optometric education in the UK. Methods: A retrospective two‐armed cross‐sectional study was conducted to investigate the perceived value of using a model eye for teaching and learning GAT in optometric education. Focus group discussion (FGD) was employed to explore the views of academic experts experienced in teaching GAT using a TME. Semi‐structured surveys were conducted to elicit the opinions of optometry students following GAT simulation training. Qualitative thematic analysis of the FGD and open‐ended survey questions was undertaken. Quantitative data based on rated student responses was assessed using Chi‐square analysis to examine differences between year‐group responses. Results: The TME was reported to be a useful experiential tool, facilitating a safe learning environment for students to develop the technical skills required to perform GAT before moving on to real‐eye experiences. Whilst limitations of the model eye were noted, these did not diminish the value of the model eye as an instructional tool. Students reported improved confidence (86%) and would highly recommend (82%) the TME to other students. Conclusion: The model eye for tonometry was perceived by academic tutors and optometry students to be a valuable instruction tool as part of a scaffolded process for learning GAT. Irrespective of their learning stage, students reported a range of benefits from the model eye, such as being able to make mistakes, taking repeat measurements and getting used to the equipment, all whilst not having to worry about patient safety. [ABSTRACT FROM AUTHOR]

Objective Animal Studied Procedures Results Conclusions To evaluate whether intracameral tissue plasminogen activator (tPA) injection is effective in regulating posterior capsular opacification (PCO), fibrin formation and intraocular pressure (IOP) after cataract surgery.Prospective study involving 30 eyes of 21 dogs that underwent phacoemulsification.Thirty eyes were randomly divided into two groups of 15 eyes (control and tPA groups). Intracameral tPA (25 μg/0.1 mL) was injected into tPA group eyes before corneal incision closure but not into the eyes of the control group. The grades of anterior fibrin formation and PCO were compared based on slit lamp biomicroscope examination at 1 and 2 weeks, 1 month, and 2–3 months postoperatively. IOP was measured using applanation tonometry every 30 min for 4 h immediately after operation and on the following morning. The IOP of the two groups at each time was compared.The grade of anterior fibrin formation and that of PCO were not significantly different between the two groups at any time point (p > .05). However, the IOP of the tPA group was significantly lower than that of the control group at each point on the day of surgery (p < .05). No complications were observed with tPA injection, except for temporary hyphema (for 3 days) in one eye.Although the intracameral tPA injection did not affect anterior fibrin formation and PCO, it effectively maintained normal IOP immediately after phacoemulsification. Thus, our findings provide valuable insights into the potential benefits of intracameral tPA injection in achieving immediate IOP control after phacoemulsification. [ABSTRACT FROM AUTHOR]

Background and Aim: Measuring intraocular pressure (IOP) is crucial for identifying potentially damaging changes in the eyes, including diseases as glaucoma and uveitis. This study compared intraocular pressure (IOP) measurements in cats using the Tonovet and Tonovet Plus (rebound), Tono-Pen Avia Vet (applanation), and Kowa HA-2 (Goldman’s methodology applanation) tonometers. Materials and Methods: 55 healthy cats (108 eyes) were assessed through three distinct studies: An ex vivo experiment (10 eyes of five cats) to correlate IOP manometry and tonometry values and ascertain the correlation coefficient (r2); an in vivo study (10 eyes of five sedated cats) to contrast manometer and tonometer readings; and an outpatient clinical trial (80 eyes of 45 cats) to analyze only tonometer measurements. Results: The r2 values observed in the ex vivo study were Tonovet (0.923), Tonovet Plus (0.925), Tono-Pen Avia Vet (0.877), and Kowa HA-2 (0.901). The IOP values in mmHg in the in vivo study were as follows: Manometer (16.1 ± 2.7), Tonovet (21.1 ± 3.6), Tonovet Plus (19.7 ± 7.2), Tono-Pen Avia Vet (17.6 ± 7.9), and Kowa HA-2 (16.8 ± 2.0). In the outpatient clinical study, the IOP values in mmHg were as follows: Tonovet (19.7 ± 6.6), Tonovet Plus (17.1 ± 5.4), Tono-Pen Avia Vet (16.3 ± 4.3), and Kowa HA-2 (14.5 ± 2.2). Conclusion: IOP and manometry readings were strongly correlated by all tonometers. In the clinical setting, the most and least IOP measurements were recorded using Tonovet and Kowa HA-2, respectively, stressing the importance of an IOP reference table for each tonometer in feline practice.

Background and Aim: Measuring intraocular pressure (IOP) is crucial for identifying potentially damaging changes in the eyes, including diseases as glaucoma and uveitis. This study compared intraocular pressure (IOP) measurements in cats using the Tonovet and Tonovet Plus (rebound), Tono-Pen Avia Vet (applanation), and Kowa HA-2 (Goldman's methodology applanation) tonometers. Materials and Methods: 55 healthy cats (108 eyes) were assessed through three distinct studies: An ex vivo experiment (10 eyes of five cats) to correlate IOP manometry and tonometry values and ascertain the correlation coefficient (r²); an in vivo study (10 eyes of five sedated cats) to contrast manometer and tonometer readings; and an outpatient clinical trial (80 eyes of 45 cats) to analyze only tonometer measurements. Results: The r² values observed in the ex vivo study were Tonovet (0.923), Tonovet Plus (0.925), Tono-Pen Avia Vet (0.877), and Kowa HA-2 (0.901). The IOP values in mmHg in the in vivo study were as follows: Manometer (16.1 ± 2.7), Tonovet (21.1 ± 3.6), Tonovet Plus (19.7 ± 7.2), Tono-Pen Avia Vet (17.6 ± 7.9), and Kowa HA-2 (16.8 ± 2.0). In the outpatient clinical study, the IOP values in mmHg were as follows: Tonovet (19.7 ± 6.6), Tonovet Plus (17.1 ± 5.4), Tono-Pen Avia Vet (16.3 ± 4.3), and Kowa HA-2 (14.5 ± 2.2). Conclusion: IOP and manometry readings were strongly correlated by all tonometers. In the clinical setting, the most and least IOP measurements were recorded using Tonovet and Kowa HA-2, respectively, stressing the importance of an IOP reference table for each tonometer in feline practice. [ABSTRACT FROM AUTHOR]

Objectives Animals Studied Methods Results Conclusions To determine normal ocular parameters of the MacQueen's bustard (Chlamydotis macqueenii) and describe ophthalmic lesions in a captive bred population.Captive breeding population of 257 Macqueen's bustards.All birds were screened for ocular abnormalities using direct ophthalmoscopy. Abnormalities were photographed. Normative values for Schirmer tear test‐1 (STT‐1), applanation tonometry, aerobic and anaerobic bacterial culture, fungal culture, and transcorneal ocular ultrasonography were derived from multiple cohorts of clinically normal adult birds. Five birds with ocular pathology also underwent transcorneal ultrasonography. Statistical comparisons for normative values between OD and OS, and males and females were made using a paired t‐test or Mann–Whitney U‐test, with a significance level of p < .05.Mean tear production based on Schirmer tear test 1 (STT‐1) was 10.16 ± 4.61 mm/min (3–21 mm/min). Mean intraocular pressure (IOP) was 12.42 ± 4.94 mm Hg (5–26 mm Hg). Staphylococcus species were the most isolated bacteria from the conjunctival surfaces of normal birds (85%). Significant differences were found in transcorneal ultrasonographic measurements between males and females for axial globe length (p = .032), vitreous body depth (p = .049) and lens thickness (p = .0428). Corneal fibrosis was the most observed ocular abnormality amongst eyes with pathological changes (39%).Schirmer tear testing, tonometry and transcorneal ultrasound can easily be utilized in MacQueen's bustards and provide reproducible results. Normal parameters for these tests were determined, and common pathological ocular changes were described in this species. [ABSTRACT FROM AUTHOR]

Background: Intraocular pressure (IOP) measurement should be accurate in a paediatric population with primary congenital glaucoma (PCG). Aim: This study aims to investigate the difference between the change in IOP measurements using rebound tonometry (RBT) and handheld applanation tonometry (AT) (Perkins applanation tonometer [PAT]) in patients with and without PCG. Setting: Johannesburg, South Africa. Methods: Measurements were taken under anaesthesia, using RBT and AT at 0 min, 5 min and 10 mins after induction and prior to intubation. Corneal pachymetry and corneal diameters were measured. Results: Sixty-five children were included, 19 with PCG and 46 without PCG. The mean age (standard deviation [s.d.]) was 3.2 (2.25) years and 4.8 (2.4) years, respectively. The overall mean difference in IOP between RBT and PAT across both PCG and non-PCG groups was found to be 4.92 mmHg (95% confidence interval [CI]: 2.80 – 7.03) p 0.001, with RBT having higher readings. This difference was greater in the PCG group, with the IOP difference of 9.05 mmHg (95% CI: 2.6 – 15.5) p = 0.004. Mean corneal pachymetry (s.d.) was 585.6 (81.48) µm in the PCG group and 518.31 (39.9) µm in the non-PCG group. Univariate analysis showed that IOP was significantly related to corneal pachymetry, with a 11 mmHg increase in IOP for every 100 μm change in corneal thickness for measurements done with RBT (p 0.001), compared to 4 mmHg using PAT (p = 0.008). Conclusion: Intraocular pressure measurements done with RBT in children with and without PCG were overestimated compared to PAT. Contribution: This difference was more pronounced in PCG patients. In addition, IOP was significantly related to corneal thickness.

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Purpose: To compare intraocular pressure (IOP) measurements between Easyton transpalpebral tonometry and Perkins, iCare iC100 and Corvis ST. Also, to assess the influence of corneal characteristics and anterior scleral thickness (AST) on the IOP measurements. Methods: Sixty-nine eyes from 69 healthy subjects were included. IOP was measured by Easyton, Perkins, iC100 and Corvis ST (corrected IOP, bIOP; and non-corrected IOP, IOPnct). Other variables studied were AST, axial length (AL), and Corvis parameters: Length 1, velocity 1, length 2, velocity 2, peak distance, radius, deformation amplitude, and central corneal thickness (CCT). Pearson correlation, limits of agreement (LoA), and multiple regression analysis were calculated. Results: No significant differences in IOP between Easyton and Perkins, iC100, and bIOP were observed (all p > 0.05), being significant only between Perkins and IOPnct (− 1.49 mmHg, p < 0.001). Bland–Altman graphs showed that the mean difference between Perkins and Easyton was 0.07 mmHg (p < 0.001), and LoA − 7.49 to + 7.39 mmHg. Significant correlations were found between the measurements of Perkins and iC100, IOPnct, bIOP (r = 0.710, 0.628, 0.539; p < 0.001 respectively), iC100 and IOPnct, bIOP (r = 0.627, 0.513; p < 0.001, respectively). The multivariate regression analysis revealed that differences between Perkins and Easyton (adjusted R2 = 0.25) were influenced by AL (B = 1.28, p < 0.008), length 1 (B = 3.13, p < 0.018), and the radius (B = 1.26, p < 0.010). Differences between Perkins and bIOP (adjusted R2 = 0.21) were affected by the CCT (B = 0.029, p < 0.003). Conclusions: There are no significant differences in the IOP measurements between Perkins and Easyton, iC100 or bIOP. Length 1, radius, and CCT have limited influence on these differences, while AST did not show any effect. [ABSTRACT FROM AUTHOR]

The investigation of arterial stiffening is a promising approach to estimating cardiovascular risk. Despite the widespread use of different methods, the dynamic nature of measured and calculated stiffness parameters is marginally investigated. We aimed to determine the stability of large artery elasticity parameters assessed via commonly used, ultrasound-based and oscillometric methods in relation to peripheral resistance modulation. A human experimental environment was composed, and fifteen young males were investigated at rest after extremity heating and external compression. Functional vascular parameters were monitored in each session, and several arterial stiffness parameters were analysed. The distensibility coefficient (DC) did not show significant changes during heat provocation and extremity compression, while DC's stability seemed to be acceptable. The same stability of carotid–femoral pulse wave velocity (PWV) was detected with ultrasound measurement (5.43 ± 0.79, 5.32 ± 0.86 and 5.28 ± 0.77, with p = 0.38, p = 0.27 and p = 0.76, respectively) with excellent intersession variability (intraclass correlation coefficient of 0.90, 0.88 and 0.91, respectively). However, the oscillometric PWV (oPWV) did change significantly between the heating and outer compression phase of the study (7.46 ± 1.37, 7.10 ± 1.18 and 7.60 ± 1.21, with p = 0.05, p = 0.68 and p < 0.001, respectively), the alteration of which is closely related to wave reflection, represented by the changes in reflection time. Our results indicate the good stability of directly measured elastic parameters such as DC and PWV, despite the extreme modulation of peripheral resistance. However, the oscillometric, indirectly detected PWV might be altered by physical interventions, which depend on wave reflection. The effective modulation of wave reflection was characterized by changes in the augmentation index, detected using both oscillometry and applanation tonometry. Thus, the environment during oscillometric measurement should be rigorously standardized. Furthermore, our results suggest the dynamic nature of the reflection point, rather than being a fixed anatomical point, proposed previously as aortic bifurcation. [ABSTRACT FROM AUTHOR]

Objectives: To determine the accuracy, precision, and clinical applicability of the ICare® TONOVET Plus (TVP) in cats. Animals and Procedures: IOP readings obtained with the TVP were compared to values obtained concurrently with the original TONOVET (TV01) and Tono‐Pen Vet™ (TP) in 12 normal cats (24 eyes) and 8 glaucomatous LTBP2‐mutant cats (13 eyes) in vivo. Reproducibility of TVP readings was also assessed for three observers in the above cats. The anterior chambers of five different normal cat eyes were cannulated ex vivo. IOP was measured with the TVP, TV01, and TP at manometric IOPs ranging from 5 to 70 mmHg. Data were analyzed by linear regression, ANOVA and Bland–Altman plots. ANOVA was used to assess reproducibility of TVP readings obtained by different observers and an ANCOVA model controlled for variation of individual cats. p <.05 was considered significant. Results: TVP values strongly correlated with TV01 values (y = 1.045x + 1.443, R2 =.9667). The TP significantly underestimated IOP relative to the TVP and TV01, particularly at high IOP. IOP values obtained by 1 observer were significantly higher (~1 mmHg average) compared to the other 2 observers via ANCOVA analysis (p =.0006479 and p =.0203). Relative to manometry, the TVP and TV01 were significantly more accurate (p <.0001) and precise (p <.0070) than the TP in ex vivo eyes. Conclusions: IOP readings obtained with the TVP and TV01 are broadly interchangeable between models and between observers, but subtle differences may be important in a research context. TP readings vastly underestimate high IOP in feline glaucoma. [ABSTRACT FROM AUTHOR]

Abstract Background Both long-term glycaemic variability and arterial stiffness have been recognized as cardiovascular risk factors. This study aims to investigate whether an association between these phenomena exists in individuals with type 1 diabetes. Methods This cross-sectional study included 673 adults (305 men, 368 women) with type 1 diabetes and combined available retrospective laboratory data on HbA1c from the preceding 10 years with outcome data on arterial stiffness and clinical variables from a comprehensive study visit. HbA1c variability was calculated as adjusted standard deviation (adj-HbA1c-SD), coefficient of variation (HbA1c-CV) and average real variability (HbA1c-ARV). As measures of arterial stiffness, carotid-femoral pulse wave velocity (cfPWV; n = 335) and augmentation index (AIx; n = 653) were assessed using applanation tonometry. Results The study population had a mean age of 47.1 (± 12.0) years and a median duration of diabetes of 31.2 (21.2–41.3) years. The median number of HbA1c assessments per individual was 17 (12–26). All three indices of HbA1c variability were significantly correlated with both cfPWV and AIx after adjustment for sex and age (p

PurposeTo assess the validity of and compare applanation and rebound tonometry readings of intraocular pressure in alert normal chicks from ages 3 to 45 days.MethodsIntraocular pressures (IOPs) were measured weekly in awake White Leghorn chicks, from ages 3-45 days (n = 22-30 per age group), with both applanation Tono-Pen and rebound TonoLab tonometers. Three repeated measurements on individual eyes were used to derive variance data for both instruments at each age. Calibration curves were also derived for each instrument and each age, weekly from ages 10-45 days (n = 3-4 per age group), from in situ manometry data collected over IOP settings of 0 to 100 mmHg in 5 mmHg steps in cannulated eyes.ResultsThe TonoLab showed less within measurement variability, but more variability with age, than the Tono-Pen. The coefficient of variation ranged from 3.8-8.3% for the TonoLab, compared to 11.0-19.7% for the Tono-Pen across all ages. For the youngest, 3 day-old chicks, mean IOPs recorded with the Tono-Pen and TonoLab were not significantly different (17.0 ± 5.6 and 15.2 ± 3.7 mmHg, respectively, P = .27). However, with increasing age, IOP readings significantly increased for the TonoLab (P

We test a new wireless soft capacitance sensor (CAP) based on applanation tonometry at the radial and dorsalis pedis arteries against the gold standard, invasive arterial line (A-Line), for continuous beat to beat blood pressure (BP) measurements in the Operating Room during surgical procedures under anesthesia in 17 subjects with the mean age and body mass index (BMI) of 57. 35 ± 18.72 years and 27.36 ± 4.20 kg/m2, respectively. We have identified several parameters to monitor in order to compare how well the CAP sensor tracks the entire hemodynamic waveform as compared to the A-Line. This includes waveform similarity, heart rate (HR), absolute systolic BP (SBP), diastolic BP (DBP), and temporal response to a vasopressor. Overall, the CAP sensor shows good correlations with A-Line with respect to hemodynamic shape (r > 0.89), HR (mean bias = 0.0006; SD = 0.17), absolute SBP, and DBP in a line of best fit (slope = 0.98 in SBP; 1.08 in DBP) and the mean bias derived from Bland-Altman method to be 1.92 (SD = 12.55) in SBP and 2.38 (SD = 12.19) in DBP across body habitus and age in OR patients under general anesthesia. While we do observe drifts in the system, we still obtain decent correlations with respect to the A-Line as evidenced by excellent linear fit and low mean bias across patients. When we post-process using a different calibration method to account for the drift, the mean bias and SD improve dramatically to -1.85 and 7.19 DBP as well as 1.43 and 7.43 SBP, respectively, indicating a promising potential for improvement when we integrate strategies to account for movement identified by our integrated accelerometer data.

BackgroundSystolic blood pressure amplification (SBPA) and pulse pressure amplification (PPA) can independently predict cardiovascular damage and mortality. A wide range of methods are used for the non-invasive estimation of SBPA and PPA. The most accurate non-invasive method for obtaining SBPA and/or PPA remains unknown.AimThis study aims to evaluate the agreement between the SBPA and PPA values that are invasively and non-invasively obtained using different (1) measurement sites (radial, brachial, carotid), (2) measuring techniques (tonometry, oscillometry/plethysmography, ultrasound), (3) pulse waveform analysis approaches, and (4) calibration methods [systo-diastolic vs. approaches using brachial diastolic and mean blood pressure (BP)], with the latter calculated using different equations or measured by oscillometry.MethodsInvasive aortic and brachial pressure (catheterism) and non-invasive aortic and peripheral (brachial, radial) BP were simultaneously obtained from 34 subjects using different methodologies, analysis methods, measuring sites, and calibration methods. SBPA and PPA were quantified. Concordance correlation and the Bland–Altman analysis were performed.Results(1) In general, SBPA and PPA levels obtained with non-invasive approaches were not associated with those recorded invasively. (2) The different non-invasive approaches led to (extremely) dissimilar results. In general, non-invasive measurements underestimated SBPA and PPA; the higher the invasive SBPA (or PPA), the greater the underestimation. (3) None of the calibration schemes, which considered non-invasive brachial BP to estimate SBPA or PPA, were better than the others. (4) SBPA and PPA levels obtained from radial artery waveform analysis (tonometry) (5) and common carotid artery ultrasound recordings and brachial artery waveform analysis, respectively, minimized the mean errors.ConclusionsOverall, the findings showed that (i) SBPA and PPA indices are not “synonymous” and (ii) non-invasive approaches would fail to accurately determine invasive SBPA or PPA levels, regardless of the recording site, analysis, and calibration methods. Non-invasive measurements generally underestimated SBPA and PPA, and the higher the invasive SBPA or PPA, the higher the underestimation. There was not a calibration scheme better than the others. Consequently, our study emphasizes the strong need to be critical of measurement techniques, to have methodological transparency, and to have expert consensus for non-invasive assessment of SBPA and PPA.

Background: Both long-term glycaemic variability and arterial stiffness have been recognized as cardiovascular risk factors. This study aims to investigate whether an association between these phenomena exists in individuals with type 1 diabetes. Methods: This cross-sectional study included 673 adults (305 men, 368 women) with type 1 diabetes and combined available retrospective laboratory data on HbA1c from the preceding 10 years with outcome data on arterial stiffness and clinical variables from a comprehensive study visit. HbA1c variability was calculated as adjusted standard deviation (adj-HbA1c-SD), coefficient of variation (HbA1c-CV) and average real variability (HbA1c-ARV). As measures of arterial stiffness, carotid-femoral pulse wave velocity (cfPWV; n = 335) and augmentation index (AIx; n = 653) were assessed using applanation tonometry. Results: The study population had a mean age of 47.1 (± 12.0) years and a median duration of diabetes of 31.2 (21.2–41.3) years. The median number of HbA1c assessments per individual was 17 (12–26). All three indices of HbA1c variability were significantly correlated with both cfPWV and AIx after adjustment for sex and age (p < 0.001). In separate multivariable linear regression models, adj-HbA1c-SD and HbA1c-CV were significantly associated with cfPWV (p = 0.032 and p = 0.046, respectively) and AIx (p = 0.028 and p = 0.049, respectively), even after adjustment for HbA1c-mean. HbA1c-ARV was not associated with cfPWV or AIx in the fully adjusted models. Conclusions: An association independent of HbA1c-mean was found between HbA1c variability and arterial stiffness, suggesting a need to consider multiple HbA1c metrics in studies assessing cardiovascular risk in type 1 diabetes. Longitudinal and interventional studies are needed to confirm any causal relationship and to find strategies for reducing long-term glycaemic variability. [ABSTRACT FROM AUTHOR]

A prospective randomized comparative placebo-controlled double-blind study was carried out based on Arterial Indices model of biological age. The study involved 60 men and women aged 40-65 years that were randomly divided into two equal groups of 30 people: the main group and the control one. The study participants from the main group received a dietary supplement containing Siberian fir terpenes, limonene, alpha-linolenic acid, and vitamin E--1 capsule 3 times a day for 90 days. Patients in the comparison group received a placebo according to a similar scheme. Anthropometric and biochemical characteristics of patients from both groups have not undergone any significant changes. According to ultrasound examination of the carotid arteries, we observed a statistically significant decrease in the minimum thickness of the intima-media complex (by 45%). The maximum carotid artery stenosis on the right or left and the expansion index in patients of both groups did not change significantly during treatment. According to the results of applanation tonometry, it was revealed that when taking the studied dietary supplement, the pulse wave velocity significantly decreased compared to the initial one (by 10%). Accordingly, the Arterial Indices biological age decreased by 2.5 years compared to the baseline level in patients of the main group and did not change in patients from the comparison group. Supplementation of fir terpenes in middle-aged patients of both sexes reduces the biological age reflecting the condition of the arteries. [ABSTRACT FROM AUTHOR]

Purpose. To estimate the accuracy of IOP measurement using artificial intelligence (AI) technologies and applanation tonometry with fixed strength. Material and methods. 290 patients (576 eyes) underwent applanation tonometry according to Maklakov with tonometer weights of 5, 10, and 15 g using a modified elastotonometry technique followed by an analysis of impression quality and diameter measurements by three independent ophthalmologist experts. The prints were then fed into a neural network to check the repeatability and reproducibility of the measurements. Results. The comparison of the diameters of the Maklakov tonometer prints determined by AI based on the neural network with the measurements data provided by three experts showed that neural network underestimates the measurement results by an average of 0.27 (-3.81; 4.35) mm Hg. At the same time, the intraclass correlation coefficient for all prints was 98.3%. The accuracy of diameter measurements of prints by neural network differs for tonometers of different weights, e.g. for a 5 g tonometer the difference was 0.06 (-3.38; 3.49) mm Hg, for 10 g and 15 g tonometers was 0.14 (-3.8; 3.51) and 0.95 (-3.84; 5.74) mm Hg, respectively. Conclusion. High accuracy and reproducibility of the measurements by the neural network, was shown to surpass the reproducibility of human-implemented measurements.

Background: The non-invasive estimation of aortic systolic (aoSBP) and pulse pressure (aoPP) is achieved by a great variety of devices, which differ markedly in the: 1) principles of recording (applied technology), 2) arterial recording site, 3) model and mathematical analysis applied to signals, and/or 4) calibration scheme. The most reliable non-invasive procedure to obtain aoSBP and aoPP is not well established. Aim: To evaluate the agreement between aoSBP and aoPP values invasively and noninvasively obtained using different: 1) recording techniques (tonometry, oscilometry/ plethysmography, ultrasound), 2) recording sites [radial, brachial (BA) and carotid artery (CCA)], 3) waveform analysis algorithms (e.g., direct analysis of the CCA pulse waveform vs. peripheral waveform analysis using general transfer functions, N-point moving average filters, etc.), 4) calibration schemes (systolic-diastolic calibration vs. methods using BA diastolic and mean blood pressure (bMBP); the latter calculated using different equations vs. measured directly by oscillometry, and 5) different equations to estimate bMBP (i.e., using a form factor of 33% (“033”), 41.2% (“0412”) or 33% corrected for heart rate (“033HR”). Methods: The invasive aortic (aoBP) and brachial pressure (bBP) (catheterization), and the non-invasive aoBP and bBP were simultaneously obtained in 34 subjects. Non-invasive aoBP levels were obtained using different techniques, analysis methods, recording sites, and calibration schemes. Results: 1) Overall, non-invasive approaches yielded lower aoSBP and aoPP levels than those recorded invasively. 2) aoSBP and aoPP determinations based on CCA recordings, followed by BA recordings, were those that yielded values closest to those recorded invasively. 3) The “033HR” and “0412” calibration schemes ensured the lowest mean error, and the “033” method determined aoBP levels furthest from those recorded invasively. 4) Most of the non-invasive approaches considered overestimated and underestimated aoSBP at low (i.e., 80 mmHg) and high (i.e., 180 mmHg) invasive aoSBP values, respectively. 5) The higher the invasively measured aoPP, the higher the level of underestimation provided by the noninvasive methods. Conclusion: The recording method and site, the mathematical method/model used to quantify aoSBP and aoPP, and to calibrate waveforms, are essential when estimating aoBP. Our study strongly emphasizes the need for methodological transparency and consensus for the non-invasive aoBP assessment. [ABSTRACT FROM AUTHOR]

Abstract Background Carotid-cavernous fistula (CCF) is an abnormal communication between the cavernous sinus and the carotid arterial system and exhibits typical symptoms of red eye, diplopia, blurred vision, headache, and murmur. However, the symptoms for CCF may vary and can lead to misdiagnosis. IOP pulsations provide a hint leading to suspicion of CCF. We report three cases related to CCF differential diagnosis: two cases of CCF patients and one case of conjunctivitis with corkscrew conjunctival vessels. Case presentation The case 1 patient, with a typical unilateral CCF, exhibited significant IOP pulsation in Goldmann tonometry measurements in the affected eye. The case 2 patient did not show typical symptoms of CCF except asymmetric upper eyelid swelling (right > left). In clinical evaluation, IOP elevation in the right eye and IOP pulsation in both eyes were noted. Based on radiology, the patient was diagnosed with bilateral CCF. The case 3 patient was referred to our institution for differential diagnosis of CCF. The patient had corkscrew conjunctival vessels in both eyes, which had appeared after he had been revived through CPR (cardiopulmonary resuscitation) 25 years prior. IOP pulsation was not observed in Goldmann tonometry. Radiology test result for arterio-venous fistula was negative in the case 3 patient. Conclusion For diagnosis of CCF, IOP pulsation by Goldmann applanation tonometry exhibits a good correlation with the disease in our cases and provides useful diagnostic clues.

Background: The non-invasive estimation of aortic systolic (aoSBP) and pulse pressure (aoPP) is achieved by a great variety of devices, which differ markedly in the: 1) principles of recording (applied technology), 2) arterial recording site, 3) model and mathematical analysis applied to signals, and/or 4) calibration scheme. The most reliable non-invasive procedure to obtain aoSBP and aoPP is not well established.Aim: To evaluate the agreement between aoSBP and aoPP values invasively and non-invasively obtained using different: 1) recording techniques (tonometry, oscilometry/plethysmography, ultrasound), 2) recording sites [radial, brachial (BA) and carotid artery (CCA)], 3) waveform analysis algorithms (e.g., direct analysis of the CCA pulse waveform vs. peripheral waveform analysis using general transfer functions, N-point moving average filters, etc.), 4) calibration schemes (systolic-diastolic calibration vs. methods using BA diastolic and mean blood pressure (bMBP); the latter calculated using different equations vs. measured directly by oscillometry, and 5) different equations to estimate bMBP (i.e., using a form factor of 33% (“033”), 41.2% (“0412”) or 33% corrected for heart rate (“033HR”).Methods: The invasive aortic (aoBP) and brachial pressure (bBP) (catheterization), and the non-invasive aoBP and bBP were simultaneously obtained in 34 subjects. Non-invasive aoBP levels were obtained using different techniques, analysis methods, recording sites, and calibration schemes.Results: 1) Overall, non-invasive approaches yielded lower aoSBP and aoPP levels than those recorded invasively. 2) aoSBP and aoPP determinations based on CCA recordings, followed by BA recordings, were those that yielded values closest to those recorded invasively. 3) The “033HR” and “0412” calibration schemes ensured the lowest mean error, and the “033” method determined aoBP levels furthest from those recorded invasively. 4) Most of the non-invasive approaches considered overestimated and underestimated aoSBP at low (i.e., 80 mmHg) and high (i.e., 180 mmHg) invasive aoSBP values, respectively. 5) The higher the invasively measured aoPP, the higher the level of underestimation provided by the non-invasive methods.Conclusion: The recording method and site, the mathematical method/model used to quantify aoSBP and aoPP, and to calibrate waveforms, are essential when estimating aoBP. Our study strongly emphasizes the need for methodological transparency and consensus for the non-invasive aoBP assessment.

Objective: To compare the agreement and repeatability of intraocular pressure (IOP) measured with the slit lamp-mounted ST500 rebound tonometer (iCare Finland Oy, Helsinki, Finland), the hand-held IC200 rebound tonometer (iCare Finland Oy) and Goldmann applanation tonometry (GAT)., Design: Cross-sectional study., Participants: Glaucoma patients and staff of the Eye Care Centre, Nova Scotia Health, Halifax, Canada., Methods: IOP was measured twice each with the IC200, ST500, and GAT. Bland-Altman analysis was used to compare each pair of tonometers and whether the difference between tonometers depended on mean IOP. Intra-class correlation coefficients were also computed. Repeatability of the measurements with each tonometer was assessed by calculating the mean and variance of the difference between the first and second measurement. The relationship between IOP and central corneal thickness was also evaluated., Main Outcome Measures: Agreement and repeatability of IOP measurements with the IC200, ST500 and GAT., Results: One eye of 157 participants (64 men and 93 women) with a median (Interquartile range) age and CCT of 62 (45 - 72) years and 553 (533 - 572) μm, respectively, were enrolled. Median IOP with the IC500, ST500 and GAT was 17.1 (14.3 - 21.0), 16.5 (14.0 - 20.8) and 17.0 (14.0 - 20.5) mm Hg, respectively, while the range of IOP (measured with GAT) was 8.5 to 53.0 mm Hg. Measurements with the three tonometers were not statistically different from each other and in neither of the three paired comparisons was the difference in IOP between two tonometers dependent on mean IOP. The ICC values (0.97-0.98) showed excellent agreement between the tonometers. The variance of the difference between the first and second measurements of the ST500 was significantly lower than that of GAT (P = 0.04) and IC200 (P < 0.01). ICCs for intra-tonometer repeatability were also excellent (0.97-0.99)., Conclusions: The ST500 shows good agreement with GAT over a large range of IOP, and significantly higher repeatability compared to the IC200 and GAT, suggesting it may be advantageous in clinical settings where topical anesthesia or skilled staff are unavailable., (Copyright © 2024. Published by Elsevier Inc.)

Background and Aim: Tonometers are an important instrument for measuring intraocular pressure (IOP) in the diagnosis of glaucoma or uveitis. This study aimed to compare the accuracy of the main types of tonometers with different IOP measurement methodologies in dogs: TonoVet and TonoVet Plus (rebound), Tono-Pen Avia Vet (applanation), and Kowa HA-2 (Goldmann applanation). Materials and Methods: IOP was measured in 152 eyes of 76 dogs. A postmortem study was performed by comparing manometry and tonometry values and calculating the correlation coefficient (r2), in vivo real IOP (manometry) among the tonometers was compared, and an outpatient study was conducted with healthy eyes and eyes with signs of glaucoma and uveitis. Results: In the postmortem study, the values of r2 in descending order were Kowa (0.989), TonoVet Plus (0.984), TonoVet (0.981), and Tono-Pen Avia Vet (0.847). The IOP values in mmHg in the in vivo study were as follows: Aneroid manometer (16.8±2.5.7), TonoVet (18.1±2.9), TonoVet Plus (20.6±2.3), Tono-Pen Avia Vet (17.1±2.5), and Kowa (16.1±1.7); in outpatient clinics: TonoVet (16.8±3.8), TonoVet Plus (19.2±2.9), Tono-Pen Avia Vet (16.2±2.4), and Kowa (15.0±1.3); glaucoma: TonoVet (30.2±3.5), TonoVet Plus (35.0±6.1), Tono-Pen Avia Vet (29.5±4.2), and Kowa (23.9±5.0); and uveitis: TonoVet (14.2±1.4), TonoVet Plus (17.6±1.9), Tono-Pen Avia Vet (13.7±2.1), and Kowa (12.6±1.7). Conclusion: There was a strong correlation between IOP values and manometry in all the tonometers. The highest values were obtained with TonoVet Plus and the lowest with Kowa HA-2. All tonometers accurately measured IOP in dogs, including the latest TonoVet Plus, which showed an excellent correlation coefficient.

Background and objectives: The aim of our study was to assess systemic and cerebral hemodynamic changes as well as cerebral CO2-reactivity during propofol anesthesia. Methods: 27 patients undergoing general anesthesia were enrolled. Anesthesia was maintained using the Target-Controlled Infusion (TCI) method according to the Schnider model, effect site propofol concentration of 4 μg.mL-1. Ventilatory settings (respiratory rate and tidal volume) were adjusted to reach and maintain 40, 35, and 30 mmHg EtCO2 for 5 minutes, respectively. At the end of each period, transcranial Doppler and hemodynamic parameters using applanation tonometry were recorded. Results: Systemic mean arterial pressure significantly decreased during anesthetic induction and remained unchanged during the entire study period. Central aortic and peripherial pulse pressure did not change significantly during anesthetic induction and maintenance, whereas augmentation index as marker of arterial stiffness significantly decreased during the anesthetic induction and remained stable at the time points when target CO2 levels were reached. Both cerebral autoregulation and cerebral CO2-reactivity was maintained during propofol anesthesia. Conclusions: Propofol at clinically administered doses using the Total Intravenous Anesthesia (TIVA/TCI) technique decreases systemic blood pressure, but does not affect static cerebral autoregulation, flow-metabolism coupling and cerebrovascular CO2 reactivity. According to our measurements, propofol may exert its systemic hemodynamic effect through venodilation. Trial registration: The study was registered at http://www.clinicaltrials.gov, identifier: NCT02203097, registration date: July 29, 2014.

BackgroundIncreased wave reflections assessed by pulse wave analysis (PWA) was proposed as one of the potential culprits of hypertension seen in women with pregnancy-associated hypertension (PAH). However, this statement has never been confirmed with “Wave Separation Analysis” (WSA), a more sophisticated mathematical approach that analyzes the amplitude and interaction between forward and backward aortic pressure waveform components.ObjectiveTo characterize potential changes in pressure wave components of PAH compared to healthy non-pregnant (NP) women and women with normal pregnancies (HP) by using WSA and compared these findings with PWA-derived indexes; secondarily, to evaluate differences in WSA-derived indexes between subgroups of PAH (i.e., preeclampsia [PE] and gestational hypertension [GH]).MethodsUsing radial and carotid applanation tonometry, we quantified in HP (n = 10), PAH (n = 16), and NP (n = 401): (i) PWA-derived indexes; (ii) WSA-derived indexes: forward (Pf) and backward (Pb) waveform components, backward component arrival time (PbAT), reflection magnitude (RM = Pb/Pf) and index [RIx = Pb/(Pf + Pb)].ResultsWhile PAH was associated with a higher Pf compared to HP and NP, Pb and PbAT were similar between the groups. Both GH and PE showed a higher Pf compared to HP, but only PE had a trend of presenting with higher Pb and lower PbAT compared to the other groups. Finally, PAH showed a trend of having lower RM and RIx compared to NP and HP, with no differences between GH and PE.ConclusionPAH was associated with higher Pf, but not higher Pb, compared to NP and HP, although PE also demonstrated a trend of higher Pb.

Background:Trabeculectomy is surgical procedure to lower intraocular pressure of eye and its outcome depends on the formation of a well-functioning bleb. In the immediate postoperative period, non-contact methods like anterior segment opticalcoherence topography(AS-OCT) is better suited.Objective: To analyze the filtration bleb morphology using AS-OCT and correlate the parameters with the intraocular pressure and to analyze the risk factors associated with outcome of filtration surgery.Material and Methods:This crosssectional study was conducted at Regional Institute of Ophthalmology, Trivandrum. 26 patients >18years of age who underwent Trabeculectomy in any case of glaucoma during the study period January 2020 to December 2021, were included in this study. Data was collected by clinical examination, AS OCT and IOP measurement by goldmann applanation tonometry. Results:Mean age of our population was around 58 years. Most common systemic illness found in our study was diabetes mellitus (27 %). Presence of diabetes had significant association with failed bleb formation (P value 0.0236). Dry eye, trauma and history of intraocular surgery were significantly more associated with failed bleb formation (p value 0.0279,0.0134,0.0240 respectively). Bleb morphology characteristics measured by OCT in the form of bleb height and thickness had significant negative correlation with intraocular pressure with Pearson correlation coefficient being -0.034 and -0.0183 respectively.Conclusion:Success following trabeculectomy for various types of glaucoma at a tertiary care hospital in kerala was 80.7% and 69.23% at 1 and 6 month respectively. Adequate control of systemic factors like glycemic status along with control of ocular factors like dry eye, preventing eye trauma and careful selection of patients can lead to better outcome in trabeculectomy patients. AS OCT parameters like bleb height and thickness can be used to predictoutcome oftrabeculectomy. [ABSTRACT FROM AUTHOR]

The cold pressor test examines the cardio-vascular reactivity during certain physiological states - rest, stress and recovery. Currently it is a widespread tool for laboratory induced stress in an experimental setting amongst various fields of science. PURPOSE: To systemize the fields of application of the cold pressor test in an attempt to outline the possibilities to analyze cardio-vascular reactivity in connection to symptoms of depression, anxiety and stress. RESULTS: Unlike similar experiments (e.g. mental arithmetic test), which actively involve the behavior and motivation of the participants, the cold pressor test is a physical stressor that passively involves the participant. Cardiovascular response (BP, heart rate, aortic pulse wave velocity) to cold pressor test is measured with applanation tonometry - a novel, simple, easy-to-use method. In CONCLUSION, the combination of the cold pressor test with speech task and mental arithmetic test would contribute to the adequate tracking and comparison of vascular and myocardial reactivity during the assessment of psychological symptoms (depression, anxiety, and stress). All of this would facilitate the involvement of the individuals with clinical or sub-clinical symptoms of depression and anxiety in experimental studies and would further help in a more precise assessment of the cardiovascular risk amongst them.

Background: Carotid-cavernous fistula (CCF) is an abnormal communication between the cavernous sinus and the carotid arterial system and exhibits typical symptoms of red eye, diplopia, blurred vision, headache, and murmur. However, the symptoms for CCF may vary and can lead to misdiagnosis. IOP pulsations provide a hint leading to suspicion of CCF. We report three cases related to CCF differential diagnosis: two cases of CCF patients and one case of conjunctivitis with corkscrew conjunctival vessels.Case Presentation: The case 1 patient, with a typical unilateral CCF, exhibited significant IOP pulsation in Goldmann tonometry measurements in the affected eye. The case 2 patient did not show typical symptoms of CCF except asymmetric upper eyelid swelling (right > left). In clinical evaluation, IOP elevation in the right eye and IOP pulsation in both eyes were noted. Based on radiology, the patient was diagnosed with bilateral CCF. The case 3 patient was referred to our institution for differential diagnosis of CCF. The patient had corkscrew conjunctival vessels in both eyes, which had appeared after he had been revived through CPR (cardiopulmonary resuscitation) 25 years prior. IOP pulsation was not observed in Goldmann tonometry. Radiology test result for arterio-venous fistula was negative in the case 3 patient.Conclusion: For diagnosis of CCF, IOP pulsation by Goldmann applanation tonometry exhibits a good correlation with the disease in our cases and provides useful diagnostic clues. [ABSTRACT FROM AUTHOR]

Aortic blood pressure (aoBP) waveform-derived indexes could provide valuable (prognostic) information over and above cardiovascular risk factors (CRFs). To obtain aoBP waveform-characteristics, several (i) techniques, (ii) recording sites, (iii) pressure-only waveform analysis mathematical approaches [e.g., pulse wave analysis (PWA), wave separation analysis (WSA)], and (iv) indexes [augmentation pressure and index (AP and AIx), forward (Pf) and backward (Pb) components of aoBP, reflection magnitude (RM), and reflection index (Rix)], were proposed. An accurate clinical use of these indexes requires knowing their physiological age-related profiles and the expected values for a specific subject. There are no works that have characterized waveform-derived indexes profiles in large populations considering: (i) as a continuous, data from different age stages (childhood, adolescence, and adulthood), (ii) complementary indexes, (iii) data obtained from different techniques and approaches, and (iv) analyzing potential sex- and body height (BH)-related differences. In addition, (v) there is a lack of normative data (reference intervals, RIs) for waveform-derived indexes. Aims: (1) to evaluate the association and agreement between PWA- and/or WSA-derived indexes obtained with different techniques and approaches; (2) to determine the need for sex-, BH-, and/or age-specific RIs; (3) to define RIs for PWA- and WSA-derived indexes in a large cohort of healthy children, adolescents, and adults. Methods: 3619 subjects (3–90 y) were included; 1688 healthy (2–84 y). AP, AIx, AIx@75, Pf, Pb, RM, and RIx were obtained (carotid and radial tonometry, brachial oscillometry/plethysmography). The association and agreement between indexes were analyzed (Concordance correlation coefficients, Bland–Altman analysis). Mean and SD equations and sex-specific BH- and age-related profiles were obtained (regression methods; fractional polynomials). Results: Waveform-derived indexes were not equivalent; for a specific index, there were systematic and proportional differences associated with the recording site (e.g., carotid vs. radial) and technique (e.g., tonometry vs. oscillometry). The need for sex-, BH-, or age-specific RIs was dependent on the index and/or age considered. RIs were defined for each index considering differences between recording sites and techniques. Equations for waveform-derived indexes age-related profiles were included, enabling to determine for a specific subject, the expected values and potential data deviations. [ABSTRACT FROM AUTHOR]

Acupuncture is an ancient Chinese form of therapy that involves needle stimulation of specific points on the body for therapeutic and homeostatic effects. In ophthalmology, acupuncture helps as a conventional or adjuvant therapy for numerous eye disorders, including myopia, strabismus, dry eye, and cataracts. This study aimed to evaluate the effect of acupuncture on tear production (TP) and intraocular pressure (IOP) in horses. Ten healthy horses, females and males with ages varying between eight months and nine years, were used. Schirmer's I test and applanation tonometry were used to evaluate the basal TP and IOP of both eyes. The measurements were taken immediately before (T10) the insertion of the needles and 5 (T5), 15 (T15), 30 (T30) and 60 (T60) minutes and 24 (T24) hours after a 20-minute acupuncture session. Mean values of both eyes were analyzed over time. TP increased in 50% of the animals at T5, T15 and T24, in 30% at T30, and in 40% at T60, with an increase of up to 8.5 mm/min at T15 and T60. In addition, there was a significant difference between T24 and T30, with a 14.1% increase in TP at T24. Meanwhile, IOP decreased in 50% of the animals at T5 and T30, in 20% at T15, in 60% at T60, and in 70% at T24. Thus, we suggest that acupuncture is a technique that can benefit horses with diseases that alter these parameters, either alone or as an adjunct in conventional therapeutic protocols. [ABSTRACT FROM AUTHOR]

Raffaele Nuzzi, Simona Scalabrin, Alice Becco Eye Clinic, Department of Surgical Sciences, University of Turin, AOU Città della Salute e della Scienza, Turin, ItalyCorrespondence: Raffaele NuzziEye Clinic of University of Turin, Turin, ItalyTel +39 0116337225Fax +39 0116335481Email prof.nuzzi_raffaele@hotmail.itPurpose: This study aims to evaluate the effectiveness of different decompressive injection techniques in reducing intraocular pressure (IOP) spikes, if compared to the injection without pressure applied on the eye, following the intravitreal injection of bevacizumab.Patients and Methods: Two hundred patients with indication to intravitreal therapy were randomized into five arms: 40 received intravitreal injection without ocular decompression (arm A), 40 with pre-injection scleral indentation with cotton swab (arm B), 40 with pre-injection digital ocular massage (arm C), 40 with post-injection scleral indentation with cotton swab (arm D) and 40 with post-injection digital ocular massage (arm E). All patients underwent measurement of the IOP with Goldamm applanation tonometer 10 minutes before and 10 minutes after the injection. The primary endpoint of the study was variation of the post- injection IOP with the different techniques.Results: An increase in post-injection IOP was observed in all the arms, if compared to pre-injection values. The greatest increase was observed in arm A with a mean IOP rise of 17.60 mmHg. All other techniques showed lower mean IOP increases: arm B 10.76 mmHg, arm C 9.35 mmHg, arm D 8.8 mmHg, arm E 3.4 mmHg. The post-injection IOP differences of innovative techniques compared to the technique without ocular decompression were all statistically significant (p-value < 0.01). If compared to arm A (35%), a reduction in IOP spike ≥ 40 mmHg frequency was also observed. The status of phakia/pseudophakia, a previous diagnosis of glaucoma and the underlying pathology for which indication was given to inject bevacizumab did not significantly alter the post-injection IOP in any of the protocols.Conclusion: The introduction of new injection protocols, such as injections performed before or after decompressive treatments, could be a safe and effective approach to control post-injection IOP increase.Keywords: bevacizumab injection, injection technique, intraocular pressure spike, digital ocular massage, scleral indentation, applanation tonometry

The combination of chronic obstructive pulmonary disease and cardiovascular disease is an urgent public health problem, that determines more severe disease progression, worse prognosis for the patient. The aim of the work was to evaluate the status of the cardiovascular system performing a pulse wave contour analysis in patients with chronic obstructive pulmonary disease depending on the severity of bronchial obstruction. Material and Methods. Applanation tonometry was performed in 60 patients (56 men, age 63.5 [IQR 59; 70] years) with chronic obstructive pulmonary disease to assess central hemodynamic parameters. The severity of obstructive disorders was determined by spirometry after taking bronchodilator. Results. In case of progression of bronchial obstruction, a decrease in parameters characterizing coronary blood flow was detected, mainly determined by an increase in heart rate and by a decrease in the duration of diastole. In addition, higher values of augmentation pressure, corrected by heart rate of 75 bpm, pulse pressure, central pulse height at the point of maximum rise of direct pulse wave were determined in patients with more severe bronchial obstruction. These parameters indicate higher values of arterial stiffness in this group of patients. Conclusion. In patients with chronic obstructive pulmonary disease and high values of bronchial obstruction there is an imbalance in the ratio of myocardial load and actual blood supply, and increased arterial stiffness with impaired aortic damping function, that contributes to the development of cardiovascular disease in this group of patients. These factors may explain high prevalence of cardiovascular disease in this group of patients.

Aortic blood pressure (aoBP) waveform-derived indexes could provide valuable (prognostic) information over and above cardiovascular risk factors (CRFs). To obtain aoBP waveform-characteristics, several (i) techniques, (ii) recording sites, (iii) pressure-only waveform analysis mathematical approaches [e.g., pulse wave analysis (PWA), wave separation analysis (WSA)], and (iv) indexes [augmentation pressure and index (AP and AIx), forward (Pf) and backward (Pb) components of aoBP, reflection magnitude (RM), and reflection index (Rix)], were proposed. An accurate clinical use of these indexes requires knowing their physiological age-related profiles and the expected values for a specific subject. There are no works that have characterized waveform-derived indexes profiles in large populations considering: (i) as a continuous, data from different age stages (childhood, adolescence, and adulthood), (ii) complementary indexes, (iii) data obtained from different techniques and approaches, and (iv) analyzing potential sex- and body height (BH)-related differences. In addition, (v) there is a lack of normative data (reference intervals, RIs) for waveform-derived indexes.Aims(1) to evaluate the association and agreement between PWA- and/or WSA-derived indexes obtained with different techniques and approaches; (2) to determine the need for sex-, BH-, and/or age-specific RIs; (3) to define RIs for PWA- and WSA-derived indexes in a large cohort of healthy children, adolescents, and adults.Methods3619 subjects (3–90 y) were included; 1688 healthy (2–84 y). AP, AIx, AIx@75, Pf, Pb, RM, and RIx were obtained (carotid and radial tonometry, brachial oscillometry/plethysmography). The association and agreement between indexes were analyzed (Concordance correlation coefficients, Bland–Altman analysis). Mean and SD equations and sex-specific BH- and age-related profiles were obtained (regression methods; fractional polynomials).ResultsWaveform-derived indexes were not equivalent; for a specific index, there were systematic and proportional differences associated with the recording site (e.g., carotid vs. radial) and technique (e.g., tonometry vs. oscillometry). The need for sex-, BH-, or age-specific RIs was dependent on the index and/or age considered. RIs were defined for each index considering differences between recording sites and techniques. Equations for waveform-derived indexes age-related profiles were included, enabling to determine for a specific subject, the expected values and potential data deviations.

The use of oscillometric methods to determine brachial blood pressure (bBP) can lead to a systematic underestimation of the invasively measured systolic (bSBP) and pulse (bPP) pressure levels, together with a significant overestimation of diastolic pressure (bDBP). Similarly, the agreement between brachial mean blood pressure (bMBP), invasively and non-invasively measured, can be affected by inaccurate estimations/assumptions. Despite several methodologies that can be applied to estimate bMBP non-invasively, there is no consensus on which approach leads to the most accurate estimation. Aims: to evaluate the association and agreement between: (1) non-invasive (oscillometry) and invasive bBP; (2) invasive bMBP, and bMBP (i) measured by oscillometry and (ii) calculated using six different equations; and (3) bSBP and bPP invasively and non-invasively obtained by applanation tonometry and employing different calibration methods. To this end, invasive aortic blood pressure and bBP (catheterization), and non-invasive bBP (oscillometry [Mobil-O-Graph] and brachial artery applanation tonometry [SphygmoCor]) were simultaneously obtained (34 subjects, 193 records). bMBP was calculated using different approaches. Results: (i) the agreement between invasive bBP and their respective non-invasive measurements (oscillometry) showed dependence on bBP levels (proportional error); (ii) among the different approaches used to obtain bMBP, the equation that includes a form factor equal to 33% (bMBP = bDBP + bPP/3) showed the best association with the invasive bMBP; (iii) the best approach to estimate invasive bSBP and bPP from tonometry recordings is based on the calibration scheme that employs oscillometric bMBP. On the contrary, the worst association between invasive and applanation tonometry-derived bBP levels was observed when the brachial pulse waveform was calibrated to bMBP quantified as bMBP = bDBP + bPP/3. Our study strongly emphasizes the need for methodological transparency and consensus for non-invasive bMBP assessment.

Background: Objectively measured breast softness in reconstructed breasts and its relation to patients' subjective satisfaction with breast softness has not yet been investigated. The aim of this study was to evaluate breast softness in patients 1 year following delayed breast reconstruction with an expander prosthesis (EP) or deep inferior epigastric perforator (DIEP) flap, using objective and subjective methods. Methods: Seventy-three patients were randomised to breast reconstruction with an EP or DIEP flap between 2012 and 2018. Of these, 69 completed objective evaluation at a mean of 25 (standard deviation, SD 9.4) months following breast reconstruction. Objective evaluation included measurements of breast volume, jugulum-nipple distance, clavicular-submammary fold distance, ptosis and Baker scale grading. Breast softness was assessed with applanation tonometry. Subjective evaluation was performed using the BREAST-Q questionnaire. Results: Objectively, DIEP flaps were significantly softer than EP breast reconstructions. Non-operated contralateral breasts were significantly softer compared with reconstructed breasts. In the subjective evaluation, the median score on the question (labelled 1.h) "How satisfied or dissatisfied have you been with the softness of your reconstructed breast (s)?" was higher in the DIEP flap group corresponding to greater satisfaction in this group. A fair correlation was found between the applanation tonometry and the patient-reported satisfaction with the reconstructed breast's softness (rs = 0.37). Conclusions: In terms of breast softness, breast reconstructions with DIEP flaps result in more satisfied patients. Concerning applanation tonometry as an objective tool for softness assessment, future studies on interobserver agreement are warranted. Level of evidence: Level I, therapeutic study [ABSTRACT FROM AUTHOR]

Background and Aim: Tonometers are an important instrument for measuring intraocular pressure (IOP) in the diagnosis of glaucoma or uveitis. This study aimed to compare the accuracy of the main types of tonometers with different IOP measurement methodologies in dogs: TonoVet and TonoVet Plus (rebound), Tono-Pen Avia Vet (applanation), and Kowa HA-2 (Goldmann applanation). Materials and Methods: IOP was measured in 152 eyes of 76 dogs. A postmortem study was performed by comparing manometry and tonometry values and calculating the correlation coefficient (r2), in vivo real IOP (manometry) among the tonometers was compared, and an outpatient study was conducted with healthy eyes and eyes with signs of glaucoma and uveitis. Results: In the postmortem study, the values of r2 in descending order were Kowa (0.989), TonoVet Plus (0.984), TonoVet (0.981), and Tono-Pen Avia Vet (0.847). The IOP values in mmHg in the in vivo study were as follows: Aneroid manometer (16.8±2.5.7), TonoVet (18.1±2.9), TonoVet Plus (20.6±2.3), Tono-Pen Avia Vet (17.1±2.5), and Kowa (16.1±1.7); in outpatient clinics: TonoVet (16.8±3.8), TonoVet Plus (19.2±2.9), Tono-Pen Avia Vet (16.2±2.4), and Kowa (15.0±1.3); glaucoma: TonoVet (30.2±3.5), TonoVet Plus (35.0±6.1), Tono-Pen Avia Vet (29.5±4.2), and Kowa (23.9±5.0); and uveitis: TonoVet (14.2±1.4), TonoVet Plus (17.6±1.9), Tono-Pen Avia Vet (13.7±2.1), and Kowa (12.6±1.7). Conclusion: There was a strong correlation between IOP values and manometry in all the tonometers. The highest values were obtained with TonoVet Plus and the lowest with Kowa HA-2. All tonometers accurately measured IOP in dogs, including the latest TonoVet Plus, which showed an excellent correlation coefficient. [ABSTRACT FROM AUTHOR]

ABSTRACT: Acupuncture is an ancient Chinese form of therapy that involves needle stimulation of specific points on the body for therapeutic and homeostatic effects. In ophthalmology, acupuncture helps as a conventional or adjuvant therapy for numerous eye disorders, including myopia, strabismus, dry eye, and cataracts. This study aimed to evaluate the effect of acupuncture on tear production (TP) and intraocular pressure (IOP) in horses. Ten healthy horses, females and males with ages varying between eight months and nine years, were used. Schirmer’s I test and applanation tonometry were used to evaluate the basal TP and IOP of both eyes. The measurements were taken immediately before (T10) the insertion of the needles and 5 (T5), 15 (T15), 30 (T30) and 60 (T60) minutes and 24 (T24) hours after a 20-minute acupuncture session. Mean values of both eyes were analyzed over time. TP increased in 50% of the animals at T5, T15 and T24, in 30% at T30, and in 40% at T60, with an increase of up to 8.5 mm/min at T15 and T60. In addition, there was a significant difference between T24 and T30, with a 14.1% increase in TP at T24. Meanwhile, IOP decreased in 50% of the animals at T5 and T30, in 20% at T15, in 60% at T60, and in 70% at T24. Thus, we suggest that acupuncture is a technique that can benefit horses with diseases that alter these parameters, either alone or as an adjunct in conventional therapeutic protocols.

We test a new wireless soft capacitance sensor (CAP) based on applanation tonometry at the radial and dorsalis pedis arteries against the gold standard, invasive arterial line (A-Line), for continuous beat to beat blood pressure (BP) measurements in the Operating Room during surgical procedures under anesthesia in 17 subjects with the mean age and body mass index (BMI) of 57. 35 ± 18.72 years and 27.36 ± 4.20 kg/m2, respectively. We have identified several parameters to monitor in order to compare how well the CAP sensor tracks the entire hemodynamic waveform as compared to the A-Line. This includes waveform similarity, heart rate (HR), absolute systolic BP (SBP), diastolic BP (DBP), and temporal response to a vasopressor. Overall, the CAP sensor shows good correlations with A-Line with respect to hemodynamic shape (r > 0.89), HR (mean bias = 0.0006; SD = 0.17), absolute SBP, and DBP in a line of best fit (slope = 0.98 in SBP; 1.08 in DBP) and the mean bias derived from Bland-Altman method to be 1.92 (SD = 12.55) in SBP and 2.38 (SD = 12.19) in DBP across body habitus and age in OR patients under general anesthesia. While we do observe drifts in the system, we still obtain decent correlations with respect to the A-Line as evidenced by excellent linear fit and low mean bias across patients. When we post-process using a different calibration method to account for the drift, the mean bias and SD improve dramatically to −1.85 and 7.19 DBP as well as 1.43 and 7.43 SBP, respectively, indicating a promising potential for improvement when we integrate strategies to account for movement identified by our integrated accelerometer data.

Background: Aortic stenosis (AS) is no longer considered to be a disease of fixed left ventricular (LV) afterload, but rather, functions as a series circuit, with important contributions from both the valve and vasculature. Patients with AS are typically elderly, with hypertension and a markedly remodelled aorta. The arterial component is sizeable, and yet, quantifying this to-date has been difficult to determine. We compared measurement of aortic pressure, flow and global LV load using a cardiac magnetic resonance (CMR)/applanation tonometry (AT) technique to uncouple ventriculo-arterial (VA) interactions. Methods: 20 healthy elderly patients and 20 with AS underwent a CMR/AT protocol. CMR provided LV volume and aortic flow simultaneously with AT pressure acquisition. Aortic pressure was derived by transformation of the AT waveform. Systemic vascular resistance (SVR) and global LV load were determined as the relationship of pressure to flow in the frequency domain. Values from both cohorts were compared. Results: AS patients were older (p ​

Radial applanation tonometry is a well-established method for clinical hemodynamic assessment and is also becoming popular in wrist-worn fitness trackers. The time difference between the foot and the dicrotic notch of the arterial pressure waveform is a well-accepted approximation for the left ventricular ejection time (ET). However, several clinical studies have shown that ET measured from the radial pressure waveform deviates from that measured centrally. In this work, we consider the systolic wave and the dicrotic wave as two independent traveling waves and hypothesize that their wave speed difference leads to the intersite differences of measured ET (DET). Accordingly, we derived a mathematical dicrotic wave decomposition model and identified the most influential factors on DET via global sensitivity analysis. In our clinical validation on a heterogeneous cohort (N = 5,742) from the Framingham Heart Study (FHS), the local sensitivity analysis results resembled the sensitivity variation patterns of DET from model simulations. A regression analysis on FHS data, using morphological features of radial pressure waveforms to estimate the carotid ET, produced a root mean square error of 3.76 ms and R2 of 0.91. The proposed dicrotic wave decomposition model can explain the intersite ET measurement discrepancies observed in the clinical data of FHS and can facilitate the precise identification of ET with radial pressure waveforms. Therefore, the proposed model will improve various physics-based pulse wave analysis methods as well as prospective artificial intelligence methods for tackling the subsequent big data produced from widespread wearable radial pressure monitoring. [ABSTRACT FROM AUTHOR]

Introduction and objective Physical effort plays a positive role in reducing the risk of cardiovascular diseases. The aim of this study was to assess the cardiovascular status in postmenopausal women after several years of regular amateur training. Material and methods A total of 55 generally healthy females aged 50–70 years, of whom 38 were members of a senior exercise group and 17 comprised a control group, were enrolled in the study. Parameters of blood flow, vascular resistance, myocardial contractility and thoracic fluid content were measured in a 10-minute supine resting test by impedance cardiography. Thereafter, central blood pressure, augmentation index and pulse wave velocity were measured by applanation tonometry. Results Exercising women have a better outcome than the control group, when evaluated both with impedance cardiography and with applanation tonometry. They have a lower heart rate – HR (65.1 vs 71.5; p = 0.033), higher blood flow (stroke index – SI, 58.6 vs 50.3; p = 0.040), better myocardial contractility (acceleration index – ACI, 108.8 vs 88.1; p = 0.027), higher preload (thoracic fluid content index – TFCI, 20.5 vs 18.1; p = 0.002), lower afterload (systemic vascular resistance index – SVRI, 1972.9 vs 2110.5; p = 0.026), lower central systolic blood pressure – cBPsys (119.0 vs 129.5; p = 0.037), lower augmentation pressure – AP (10.3 vs 15.0; p = 0.044) and lower pulse wave velocity – PWV (7.4 vs 8.4; p = 0.001). Conclusions Regular moderate continuous aerobic exercise training has a beneficial impact on the cardiovascular system in postmenopausal women.

Introduction: Glaucoma is characterised by structural damage to optic nerve head with corresponding visual field defects and often associated with increased Intraocular Pressure (IOP). It may be broadly classified as Primary Angle Closure Glaucoma (PACG) and Primary Open Angle Glaucoma (POAG). It is one of the leading causes of global blindness, and a major proportion occurs in Indian population. Aim: To study the correlation between pretreatment IOP and extent of visual field loss in PACG and POAG. Materials and Methods: A cross-sectional observational study was carried out in Regional Institute of Ophthalmology, Trivandrum, Kerala, India from April 2016 to May 2017. Newly diagnosed cases of PACG (25 patients-13 males, 12 females, mean age 58.72±10.07 years) and POAG (85 patients- 45 males, 40 females, mean age 60.28±10.42 years) underwent a detailed glaucoma evaluation which included IOP measurement with Goldmann applanation tonometer and visual field testing using Humphrey Field Analysis (HFA) 24-2 pattern. Mean Deviation (MD), Pattern Standard Deviation (PSD) and Advanced Glaucoma Intervention Score (AGIS) score was calculated from reliable visual field test result. All data were coded and entered in to statistical software, Statistical Package for Social Sciences (SPSS) version 16.0 for analysis. The correlation between pretreatment IOP and visual field loss in patients with PACG and POAG was determined by Pearson Correlation of Coefficient. Results: Amongst the total 110 patients of this study, 25 patients were of PACG while POAG were in 85 patients. A significant correlation between pre treatment IOP and the extent of visual field loss in PACG was noted. There was no significant correlation in POAG. Linear regression analysis demonstrated a significant positive correlation between IOP and AGIS score in PACG (Pearson correlation coefficient(r)=0.805, p0.450). Conclusion: A significant correlation between IOP and visual field loss in PACG indicates that extent of visual field damage can be controlled by controlling IOP alone in PACG. The correlation between the pretreatment IOP and visual field loss in POAG is not statistically significant which agrees with the current proposed pathophysiology of optic neuropathy in which multiple factors influence in addition to IOP.

Introduction: Glaucoma is characterised by structural damage to optic nerve head with corresponding visual field defects and often associated with increased Intraocular Pressure (IOP). It may be broadly classified as Primary Angle Closure Glaucoma (PACG) and Primary Open Angle Glaucoma (POAG). It is one of the leading causes of global blindness, and a major proportion occurs in Indian population. Aim: To study the correlation between pretreatment IOP and extent of visual field loss in PACG and POAG. Materials and Methods: A cross-sectional observational study was carried out in Regional Institute of Ophthalmology, Trivandrum, Kerala, India from April 2016 to May 2017. Newly diagnosed cases of PACG (25 patients-13 males, 12 females, mean age 58.72±10.07 years) and POAG (85 patients-45 males, 40 females, mean age 60.28±10.42 years) underwent a detailed glaucoma evaluation which included IOP measurement with Goldmann applanation tonometer and visual field testing using Humphrey Field Analysis (HFA) 24-2 pattern. Mean Deviation (MD), Pattern Standard Deviation (PSD) and Advanced Glaucoma Intervention Score (AGIS) score was calculated from reliable visual field test result. All data were coded and entered in to statistical software, Statistical Package for Social Sciences (SPSS) version 16.0 for analysis. The correlation between pretreatment IOP and visual field loss in patients with PACG and POAG was determined by Pearson Correlation of Coefficient. Results: Amongst the total 110 patients of this study, 25 patients were of PACG while POAG were in 85 patients. A significant correlation between pre treatment IOP and the extent of visual field loss in PACG was noted. There was no significant correlation in POAG. Linear regression analysis demonstrated a significant positive correlation between IOP and AGIS score in PACG (Pearson correlation coefficient(r)=0.805, p<0.001), not in POAG (r=0.026, p=0.816). Correlation between IOP and MD is statistically significant in PACG (r=0.812, p<0.001) but not in POAG (r=0.058, p=0.597). The correlation between IOP and PSD is not statistically significant in both groups (p-value >0.450). Conclusion: A significant correlation between IOP and visual field loss in PACG indicates that extent of visual field damage can be controlled by controlling IOP alone in PACG. The correlation between the pretreatment IOP and visual field loss in POAG is not statistically significant which agrees with the current proposed pathophysiology of optic neuropathy in which multiple factors influence in addition to IOP. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether the order of intraocular pressure (IOP) measurement affects readings, regardless of which eye is measured first. Methods: Intraocular pressure was measured in 31 and 41 dogs using applanation and rebound tonometry, respectively. Initially, IOP was measured in the first (randomly chosen) eye (reading A), followed by measurement in the fellow eye (reading B), and a third (repeated) measurement in the first eye (reading C). After 15 minutes, measurements were repeated in reverse order (readings D ‐ F). Results: Applanation tonometry revealed significant differences between readings A & B (15.6 ± 2.3 and 14.8 ± 2.7 mm Hg, respectively, p =.02), A & C (15.6 ± 2.3 and 14.5 ± 2.4 mm Hg, respectively, p =.002), D & E (14.5 ± 2.3 and 13.7 ± 2.1 mm Hg, respectively, p =.02), D & F (14.5 ± 2.3 and 13.9 ± 1.9 mm Hg, respectively, p =.05), and A & E (15.6 ± 2.3 and 13.7 ± 2.1 mm Hg, respectively, p =.001). Rebound tonometry yielded similar results, with additional differences between B & C (19.1 ± 3.0 and 18.2 ± 2.4 mm Hg, respectively, p =.002) and E & F (18.7 ± 3.3 and 18.2 ± 3.3 mm Hg, respectively, p =.02). Conclusions: Intraocular pressure measured in the first eye, whether right or left, is higher than in the fellow eye. Repeated tonometry in the same visit could result in a significant IOP decrease, though the magnitude may not be clinically appreciable. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the effects of four different drugs used for anaesthesia premedication on intraocular pressure and pupil size in dogs. A prospective, randomised, double-blind clinical study was carried out. The subjects were forty client-owned healthy dogs (20 males and 20 females), aged 8.0 ± 2.9 years, with body weights of 11.8 ± 8.5 kg (mean ± SD) and without ocular abnormalities that were scheduled for periodontal treatment. Animals were randomly allocated into four groups and received intravenously either medetomidine 0.01 mg/kg, acepromazine 0.02 mg/kg, fentanyl 0.01 mg/kg or butorphanol 0.2 mg/kg. Intraocular pressure, pupil size, heart rate, respiratory frequency and systolic and diastolic arterial pressures were measured prior to (baseline) and at five and 10 minutes after premedication (T5, T10). Data were analysed by Anderson-Darling, Bartlett's, ANOVA and Dunnett's tests (P < 0.05). Significant increases of intraocular pressure were observed at T5 and T10 in the fentanyl group. Significant decreases of pupil size at T5 and T10 were detected in the fentanyl, butorphanol and medetomidine groups. In the fentanyl group, heart rate dropped significantly at T10, while respiratory frequency was elevated at T5 and T10. In the medetomidine group, heart rate and respiratory frequency were decreased at T5 and T10. In the butorphanol group, systolic arterial pressure was decreased at T5 and diastolic arterial pressure was decreased at T5 and T10. In the acepromazine group, systolic arterial pressure was decreased at T10. Within ten minutes after intravenous administration in healthy dogs, fentanyl significantly increased intraocular pressure and fentanyl, butorphanol and medetomidine decreased pupil size.