UNASSIGNED: To evaluate the accuracy of the new Tono-Vera rebound tonometer (Reichert Inc, Buffalo, NY) compared to Goldmann Applanation Tonometry.
UNASSIGNED: This prospective, observational, cross-sectional study was designed in accordance with ANSI Z80.10-2014 and ISO 8612-2009 guidelines for tonometer comparison. Intraocular Pressure (IOP) was measured by Goldmann Applanation and Tono-Vera on 160 eyes of 160 subjects. Corneal Astigmatism and Central Corneal Thickness were also measured. A single investigator (CN) conducted all measurements. The average of two measurements from each tonometer was used in the analysis. Bland-Altman plots, total least squares regression analysis, and simple linear regression were used to evaluate agreement between the tonometers.
UNASSIGNED: Average IOP values from Goldmann Applanation and Tono-Vera were not significantly different (19.17 and 19.03 respectively, p=0.40, paired t-test). The total least squares regression analysis indicated strong agreement between the two tonometers (slope +0.97, offset +0.49 mmHg, standard deviation 2.11 mmHg). There were 2 IOP measurement pairs that exceeded the ± 5 mmHg limits of agreement required in ANSI Z80.10-2014 and ISO 8612-2009, which is within the range of acceptability specified in the standards.
UNASSIGNED: We evaluated IOP measurements by Tono-Vera Rebound Tonometer vs Goldmann Applanation Tonometry for eyes with a wide range of IOP values and found no statistically significant differences in the results. Tono-Vera meets the requirements of ANSI Z80.10-2014 and ISO 8612-2009, demonstrating accuracy comparable to Goldmann tonometry.

Fifty-five healthy conscious dogs were included in a prospective randomised double-blinded clinical study. The dogs allocated to one of four groups received intravenous bolus followed by infusion of fentanyl (FEN-group), or ketamine (KET-group), or lidocaine (LID-group), or saline (SAL-group). The intraocular pressure (IOP), pupil size (PS), heart rate (HR) and mean arterial pressure (MAP) were measured prior to and at 2, 5, 10, 20 and 30 min after initiation of the drug administration. The data were analysed using an analysis of variance and the Steel-Dwass test. No significant difference in the IOP within or between the groups was detected. In the FEN-group, the PS decreased significantly at all the measured times. In the KET-group, the PS increased significantly at 2, 5 and 10 minutes. The PS was significantly smaller in the FEN-group compared to the KET-group at 2, 5, 10 and 20 min, compared to the SAL-group at 5, 10, 20 and 30 minutes. In the FEN-group the HR significantly decreased compared to the baseline and was significantly lower compared to the KET-group and LID-group. Fentanyl, ketamine or lidocaine administered at the doses studied as a bolus followed by a 30-min infusion seem to cause no effect on the IOP in healthy conscious non-painful dogs without ocular abnormalities. Fentanyl decreased and ketamine transiently increased the PS.

OBJECTIVE: Standardization of eye care data is important for clinical interoperability and research . We aimed to address gaps in the representations of glaucoma examination concepts within Systemized Nomenclature of Medicine - Clinical Terms (SNOMED-CT), the preferred terminology of the American Academy of Ophthalmology.
METHODS: Study of data elements.
METHODS: Structured eye exam data fields from two electronic health records (EHR) systems (Epic Systems and Medisoft) were compared against existing SNOMED-CT codes for concepts representing glaucoma examination findings3. Glaucoma specialists from multiple institutions were surveyed to identify high-priority gaps in representation, which were discussed among the SNOMED International Eye Care Clinical Reference Group. Proposals for new codes to address the gaps were formulated and submitted for inclusion in SNOMED-CT.
METHODS: Gaps in SNOMED-CT glaucoma examination concept representations RESULTS: We identified several gaps in SNOMED-CT regarding glaucoma examination concepts. A survey of glaucoma specialists identified high-priority data elements within the categories of tonometry and gonioscopy. For tonometry, there was consensus that we need to define new codes related to maximum intraocular pressure (IOP) and target IOP, and to delineate all methods of measuring IOP. These new codes were proposed and successfully added to SNOMED-CT for future use. Regarding gonioscopy, the current terminology did not include the ability to denote the gonioscopic grading system used (e.g., Shaffer or Spaeth), degree of angle pigmentation, iris configuration (except for plateau iris), and iris approach. There was also no ability to specify eye laterality or angle quadrant for gonioscopic findings. We proposed a framework for representing gonioscopic findings as observable entities in SNOMED-CT.
CONCLUSIONS: There are existing gaps in the standardized representation of findings related to tonometry and gonioscopy within SNOMED-CT. These are important areas for evaluating clinical outcomes and enabling secondary use of EHR data for glaucoma research. This international, multi-institutional collaborative process enabled identification of gaps, prioritization, and development of data standards to address these gaps.
CONCLUSIONS: Addressing these gaps and augmenting SNOMED-CT coverage of glaucoma examination findings could enhance clinical documentation and future research efforts related to glaucoma.

Background: The purpose of this investigation was to determine the elastic characteristics of the common carotid artery (CCA) during endurance exercise at 3 different intensities. Methods: Twenty young healthy participants (10 males and 10 females) participated in this quasi-experimental cross-sectional study. Participants were tested in two sessions: (1) we took resting measurements of the elastic characteristics of the CCA and performed a cardiopulmonary exercise test (CPET) on a cycle ergometer to determine submaximal exercise intensities, and we conducted (2) measurements of the elastic characteristics of the CCA while exercising in a cycle ergometer at 3 intensities based on blood lactate levels of low (<2 mmol/L), moderate (2-4 mmol/L), and high (>4 mmol/L). Beta stiffness was calculated using CCA diameters during systole and diastole, measured with high-definition ultrasound imaging, and CCA systolic and diastolic pressures were measured via applanation tonometry. Results: Overall, there were no differences between males and females in terms of any of the studied variables (p > 0.05). In addition, no significant changes were found in the CCA beta stiffness and vessel diameter (p > 0.05) between exercise intensities. There was a significant exercise intensity effect on CCA systolic pressure (p < 0.05), but not on CCA diastolic pressure (p > 0.05). Conclusions: The biomechanical characteristics of the CCA, determined via compliance and beta-stiffness, do not change during cyclical aerobic exercise, regardless of exercise intensity.

BACKGROUND: This study aimed to compare the intraocular pressure (IOP) values obtained from two groups of dogs using the IOPvet indentation tonometer to those obtained from the same dogs using an established rebound tonometer (TONOVET Plus).
METHODS: Tonometry was performed on 36 dogs with ocular diseases (70 eyes; group A) and 25 healthy dogs (49 eyes; group B). First, the TONOVET Plus rebound tonometer was used. Then, one drop of oxybuprocaine hydrochloride was applied to each eye, and 1 minute later, the IOP was estimated using the IOPvet.
RESULTS: The IOPvet was safe, well tolerated and easy to use. The instrument had a high specificity (98.5%) for identifying IOPs of 20 mmHg or less. A lack of sensitivity (67.9%) was noted when evaluating eyes with an IOP between 20 and 30 mmHg. The sensitivity (33.3%) for identifying canine eyes with an IOP of greater than 30 mmHg (n = 24) was low.
CONCLUSIONS: This study lacks manometric work, which would be hard to justify with client-owned dogs. Quantitative numerical data were compared with qualitative values and the same investigator obtained readings using both tonometers without being masked.
CONCLUSIONS: The IOPvet is highly sensitive for assessing normal IOPs, but underestimation of higher IOPs can lead to poor diagnostics. Digital tonometers remain the best way to assess IOP in veterinary clinics.

This study investigated intraocular pressure (IOP) in Dutch belted rabbits using two different tonometers, rebound tonometry (TonoVet Plus; TVP) and a Tonopen (Tono-Pen AVIA Vet; TPA). Post-pubescent male Dutch belted rabbits aged 36 weeks (n = 10 animals) were used in the study. IOP measurements were conducted every 2 weeks for 22 weeks using TVP and TPA on both eyes of each rabbit. The average IOP measurements were compared by the paired Student\'s t-test. Pairwise Pearson\'s correlation coefficients and Bland-Altman statistics were used. The overall mean IOP measured with TPA was significantly higher than that with TVP (23.5 ± 4.9 vs. 21.8 ± 2.4 mmHg for the right eyes; P = 0.045, and 23.0 ± 4.7 vs. 21.5 ± 2.4 mmHg for the left eyes; P = 0.047). Both tonometers tended to show increased IOP readings with age, and positive correlations between IOP and age were observed with both TPA (r = 0.95, P < 0.001 for right eyes; r = 0.95, P < 0.001 for left eyes) and TVP (r = 0.91, P < 0.001 for right eyes; r = 0.64, P = 0.024 for left eyes). The average bias calculated by subtracting TPA from TVP was - 1.60 (95% confidence intervals - 1.927, - 1.281) mmHg. IOP in post-pubescent Dutch belted rabbits tended to increase with age throughout the 22 week study.

OBJECTIVE: This study investigates the influence of peripheral corneal thickness (PCT) and its curvature on tonometry readings.
METHODS: The study included 49 patients (49 eyes) who were indicated for glaucoma surgery. Using bidirectional applanation tonometry, the following parameters were obtained: IOPcc, IOPg - intraocular pressure (IOP) corrected for corneal compensation, taken as the most reliable indicator; IOP converted to Goldmann measurement, taken as the result of applanation tonometry, ΔIOP (IOPcc-IOPg), CH and CRF (corneal hysteresis and corneal resistance factor). During corneal topography, the corneal thickness was studied in the center, PCT at 1.5; 2, 3, 4 and 5 mm from the center in four meridians, as well as ΔPCT (PCT 3 mm - PCT 1.5 mm), the curvature of the anterior and posterior surfaces of the cornea and the depth of the anterior chamber. Aberrometry was used to obtain refractometry data and the curvature of the anterior surface of the cornea. The influence of the studied parameters on ΔIOP was evaluated.
RESULTS: ΔIOP correlated with CRF (r= -0.652), CH (r= -0.873), central corneal thickness (r= -0.293), PCT at all distances except 5 mm (r= -0.297; -0.287; -0.302; -0.303), with the strong and weak meridians of the anterior surface of the cornea (r=0.328; r=0.315), with the strong and weak meridians of the posterior surface, as well as the average curvature of the posterior surface (r=0.307; r=0.332; r=0.328). After step-by-step selection of the above parameters for creating a linear regression model for ΔIOP calculation, CH, CRF and PCT1.5mm remained in the model. The model describes ΔIOP with high accuracy (R2=0.974).
CONCLUSIONS: Biomechanical parameters of the cornea are the leading factor of applanation tonometry error. Individual linear dimensions of the cornea (thickness, curvature) have a lesser effect.
UNASSIGNED: Изучить влияние периферической толщины роговицы (ПТР) и ее кривизны на результаты тонометрии.
UNASSIGNED: Исследовали 49 пациентов (49 глаз), которым была показана антиглаукомная операция. С помощью двунаправленной аппланационной тонометрии получили показатели IOPcc, IOPg, внутриглазное давление (ВГД) роговично-компенсированное, принятое за максимально достоверный показатель; ВГД, приведенное к измерению по Гольдману, принятое за результат аппланационной тонометрии, ΔВГД (IOPcc—IOPg), CH и CRF (роговичный гистерезис и фактор резистентности роговицы). При кератотопографии исследовали толщину роговицы в центре, ПТР на 1,5; 2, 3, 4 и 5 мм от центра в четырех меридианах, а также ΔПТР (ПТР 3 мм — ПТР 1,5 мм), кривизну передней и задней поверхностей роговицы и глубину передней камеры. При аберрометрии получали данные рефрактометрии и кривизну передней поверхности роговицы. Оценивали влияние изученных параметров на ΔВГД.
UNASSIGNED: ΔВГД коррелирует с CRF (r= –0,652), СН (r= –0,873), центральной толщины роговицы (r= –0,293), ПТР на всех расстояниях, кроме 5 мм (r= –0,297; –0,287; –0,302; –0,303), с сильным и слабым меридианом передней поверхности роговицы (r=0,328; r=0,315), с сильным и слабым меридианом задней поверхности, а также средней кривизной задней поверхности (r=0,307; r=0,332; r=0,328). При шаговом отборе вышеуказанных показателей для создания линейной регрессионной модели расчета ΔВГД в модели остались CH, CRF и ПТР1,5мм. Модель описывает ΔВГД с высокой точностью (R2=0,974).
UNASSIGNED: Биомеханические показатели роговицы являются ведущим фактором погрешности аппланационной тонометрии. Меньшее влияние оказывают отдельные линейные размеры роговицы (толщина, кривизна).

The aim of this study was to evaluate the intraocular pressure (IOP) measurements obtained from first, second, and third probe-cornea touch (PCT) and compare them with the average of six PCTs using two rebound tonometers in horses. This study enrolled a total of thirty-eight stallions, comprising of 24 Arabian horses and 14 cross-breeds (with an average age of 8 ± 3 years). The IOP measurements of first, second, and third, as well as the average of six PCTs were obtained using either Tonovet (TV) or Tonovet Plus (TV+) rebound tonometers. The mean differences (95% limits of agreement) between the average of six PCTs and the first, second, and third PCTs were 0.1 (-4.8 to 5), 0.2 (-4.8 to 4.5), and 0.2 (-3.6 to 4.0) mmHg with TV, respectively. With TV+, the differences were 0.3 (-6.6 to 7.2), 1.1 (-8.6 to 10.8), and -0.2 (-3.6 to 4.0) mmHg, respectively. Compared to the average of six PCTs, only 89.5%, 92.1%, and 97.4% of IOP measurements obtained from TV and 78.9%, 73.3%, and 65.8% of IOP measurements obtained from TV+ were within 4 mmHg of the average of six PCTs for first, second, and third PCTs, respectively. In conclusion, the measurement of IOP in the first PCT achieved best agreement with the IOP measurement of six average PCTs. Therefore, the first PCT could be considered as an alternative option for measuring IOP in horses when obtaining an average of six PCTs is not feasible.

OBJECTIVE: To assess the accuracy of canine intraocular pressure (IOP) estimates from the eyeTelemed IOPvet indentation tonometer.
METHODS: Part 1 included 54 eyes from 28 Beagle dogs-23 ADAMTS10-mutants with open-angle glaucoma and 5 normals. Part 2 involved five normal canine ex vivo globes.
METHODS: Part 1 (in vivo) compared IOPvet estimates in normal and glaucomatous dogs to Reichert Tono-Vera® Vet rebound tonometry. The three IOPvet estimates were green (normal; <20 mmHg, according to the manufacturer), yellow (elevated; 20-30 mmHg), and red (high; >30 mmHg). In Part 2 (ex vivo), the pressure inside freshly enucleated normal canine eyes was progressively increased from 5 to 80 mmHg and compared to IOPvet estimates. Descriptive statistics compared IOPvet estimates to rebound tonometry and direct manometry, with the threshold from normal to glaucoma set at 30 mmHg.
RESULTS: In Part 1 (in vivo), normal pressures (≤30 mmHg) were mainly identified correctly as green or yellow-110 of 111 estimates, corresponding to a specificity of 99%. Only 16 of 125 affected estimates were correctly displayed in the >30-mmHg range; the remaining 109 showed ≤30 mmHg, corresponding to a sensitivity of 13%. In Part 2 (ex vivo), all normal pressures were correctly estimated with green, but 64 of 88 manometric IOPs >30 mmHg were falsely estimated as 20-30 mmHg.
CONCLUSIONS: The IOPvet is inaccurate in estimating canine IOP with a low sensitivity at identifying dogs with IOP > 30 mmHg. Canine-specific instrument revision is required to correctly identify elevated (yellow = 20-30 mmHg) and high (red >30 mmHg) IOPs.

The acute reduction in peripheral arterial stiffness during reactive hyperemia is assumed to be flow-mediated; however, the mechanism remains unproven. We hypothesized that restricting the blood flow increase during reactive hyperemia would abolish the reduction in peripheral arterial stiffness. Fourteen healthy young adults (5 females, 25 ± 5 years, mean ± SD) underwent reactive hyperemia with a rapid-release cuff on the upper arm inflated to 220 mmHg for 5 min: once with unrestricted blood flow and once with restricted blood flow by manually applying pressure to the brachial artery. Brachial-radial pulse wave velocity (PWV) was measured with tonometers over brachial and radial arteries before cuff inflation and at 5, 15, and 30 min after release. Brachial blood flow was monitored with Doppler ultrasound. Baseline brachial-radial PWV was similar between conditions (10.3 ± 1.8 vs. 10.7 ± 1.7 m/s). With unrestricted flow, PWV decreased 5 min post-reactive hyperemia (8.6 ± 1.1 m/s; p < 0.05) and returned near baseline at 15 and 30 min post (p < 0.05). With restricted flow, PWV did not change (p > 0.05) post-reactive hyperemia. Reactive hyperemia acutely reduced peripheral arterial stiffness, but not when brachial artery blood flow increase was restricted. This suggests that the reduction in peripheral arterial stiffness during reactive hyperemia depends on increased blood flow.