6,146 research outputs found
Goldmann applanation tonometry eye procedures manual
This manuscript is a guide to using the Goldmann Applanation Tonometry Eye (GATE), This device permits the student to learn applanation tonometry Without the anxiety of using human subjects. Detailed instructions accompanied by photographs are presented. A brief theoretical discussion of Goldmann applanation tonometry is included
The Association of Central corneal thickness with Intra-ocular Pressure and Refractive Error in a Nigerian Population
The purpose of this study was to determine the variation of central corneal thickness (CCT) with intraocular pressure (IOP) and spherical equivalent refractive error. A total of thirty-nine (N=39) subjects within 20-75 years with mean age 45.2 ± 15.4 years were used for this study. The central corneal thickness was assessed with the Corneo-Gage plus ultrasonic Pachymeter, the IOP with slit-lamp mounted Goldmann applanation tonometer and refractive status by Protec 2000 autorefractor, phoropter and trial lens set. Results obtained showed that there was no linear correlation between CCT and spherical equivalent errors, although the association between them was significant (p<0.05). The linear correlation between CCT and IOP was not statistically significant. The central corneal thickness was weakly correlated with age; with increasing age the central corneal thickness decreases. Neither the central corneal thickness nor the intraocular pressure was affected by gender
Intraocular pressure in a cohort of healthy Eastern European schoolchildren: variations in method and corneal thickness
BACKGROUND:
Intraocular pressure (IOP) in the developing eye of a child is not always easy to measure and there is no technique that is known to be the most accurate for the young eye. Measurements are needed on many cohorts of children with different tonometers to determine how the values correlate between instruments, whether corneal parameters affect readings and whether correlations between age and IOP values can be discerned. The aim of this study was to undertake a comparative analysis of three different tonometers on a group of healthy children to see whether differences exist and whether these may be related to central corneal thickness and/or radius of curvature. In addition, the study adds to the relatively small body of literature on IOP in the growing eye which will collectively allow trends to be identified and ultimately norms to be established.
METHODS:
IOP was measured on 115 eyes in a group of Polish children, aged between 5-17 years (mean±standard deviation [SD] 11.3±3.0 years) using three different tonometers: non-contact (NCT), the ICare and Goldmann applanation (GAT). Readings obtained were compared between instruments and with central corneal thickness and radius of curvature.
RESULTS:
The ICare tonometer provided statistically higher IOP values (16.9±3.4 mmHg) than the GAT (14.7±2.9 mmHg) regardless of corneal thickness and whether or not a correction factor was applied. A correlation was found between central corneal thickness (CCT) and IOP values obtained with all three tonometers but only the IOP values detected with the ICare tonometer showed a statistically significant correlation with radius of curvature (p<0.004). No correlations with age or gender were found for IOP values measured with any of the instruments.
CONCLUSIONS:
IOP measurements on children vary significantly between instruments and correlations are affected by the corneal thickness. Further studies on children are needed to determine which instrument is most appropriate and to derive a normative IOP scale for the growing eye
The acute effect of maximal exercise on central and peripheral arterial stiffness indices and hemodynamics in children and adults
Xavier Melo is supported by a research grant from the Foundation for Science and Technology (FCT),
Ministry of Education and Science of Portugal (grant: SFRH/ BD/ 70515/ 2010). Nuno M. Pimenta is cofinanced by national funds through the Programa Operacional do Alentejo 2007-2013 (ALENT-07-0262-
FEDER-001883)This study compared the effects of a bout of maximal running exercise on arterial stiffness in children and adults. Right carotid blood pressure and artery stiffness indices measured by pulse wave velocity (PWV), compliance and distensibility coefficients, stiffness index α and β (echo-tracking), contralateral carotid blood pressure, and upper and lower limb and central/aortic PWV (applanation tonometry) were taken at rest and 10 min after a bout of maximal treadmill running in 34 children (7.38 ± 0.38 years) and 45 young adults (25.22 ± 0.91 years) having similar aerobic potential. Two-by-two repeated measures analysis of variance and analysis of covariance were used to detect differences with exercise between groups. Carotid pulse pressure (PP; η(2) = 0.394) increased more in adults after exercise (p < 0.05). Compliance (η(2) = 0.385) decreased in particular in adults and in those with high changes in distending pressure, similarly to stiffness index α and β. Carotid PWV increased more in adults and was related to local changes in PP but not mean arterial pressure (MAP). Stiffness in the lower limbs decreased (η(2) = 0.115) but apparently only in those with small MAP changes (η(2) = 0.111). No significant exercise or group interaction effects were found when variables were adjusted to height. An acute bout of maximal exercise can alter arterial stiffness and hemodynamics in the carotid artery and within the active muscle beds. Arterial stiffness and hemodynamic response to metabolic demands during exercise in children simply reflect their smaller body size and may not indicate a particular physiological difference compared with adults.info:eu-repo/semantics/publishedVersio
Recommended from our members
Agreement of three tonometers with Goldmann Applanation Tonometry (GAT)
Recommended from our members
Initial experience in self-monitoring of intraocular pressure.
Background/aims: Diurnal variation in intraocular pressure (IOP) is a routine assessment in glaucoma management. Providing patients the opportunity to perform self-tonometry might empower them and free hospital resource. We previously demonstrated that 74% of patients can use the Icare® HOME tonometer. This study further explores Icare® HOME patient self-monitoring.
Methods: Patients were trained by standard protocol to use the Icare® HOME rebound tonometer. Patient self-tonometry was compared to Goldmann applanation tonometry (GAT) over one clinical day. Following this, each patient was instructed to undertake further data collection that evening and over the subsequent two days.
Results: Eighteen patients (35 eyes) participated. Good agreement was demonstrated between GAT and Icare® HOME for IOPs up to 15 mm Hg. Above this IOP the Icare® tended to over-read, largely explained by 2 patients with corneal thickness >600 um. The mean peak IOP during ‘clinic hours’ phasing was 16.7 mm Hg and 18.5 mm Hg (p = 0.24) over three days. An average range of 5.0, 7.0 and 9.8 mm Hg was shown during single day clinic, single day home and three day home phasing respectively (p =<0.001). The range of IOP was lower in eyes with prior trabeculectomy (6.1 mm Hg vs 12.2 mm Hg). All patients undertook one reading in the early morning at home with an average of 4.8 readings during, and 3.1 readings after office hours.
Conclusions: This small study shows that self-tonometry is feasible. The findings from home phasing demonstrated higher peak and trough IOPs, providing additional clinical information. Home phasing is a viable alternative. The cost-effectiveness of this approach has yet to be addressed
Rebound tonometry compared with goldmann applanation tonometry in patients with corneal pathology - a reliability study
A research report submitted to the Faculty of Health Sciences, University of the
Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the
degree of
Master of Science in Medicine in the branch of Ophthalmology
Johannesburg, November 2016Purpose: To compare the reliability of rebound tonometry (RT) with that of Goldmann
applanation tonometry (GAT) in patients with corneal scars.
Methods: Three measurements were taken with each instrument. Instruments were
compared by determining the differences between repeat measurements, by using a nonparametric
ANOVA on repeat measurements and by calculating the coefficient of
repeatability (CR). A control group with normal corneas were examined to establish
baseline correlation, repeatability and observer proficiency.
Results: 61 eyes of 48 patients were included in the group with scarred corneas. The CR of
RT was 2.667. The CR of GAT was 4.819. RT was more reliable than GAT in patients
with corneal scars. The correlation coefficient of RT with GAT was 0.8959.
Conclusion: RT correlated well with GAT in both scarred and control subjects. RT was
more reliable than GAT in patients with corneal scars. GAT was more reliable than RT in
control patients.MT201
Dynamic contour tonometry versus Goldmann applanation tonometry: challenging the gold standard
The accurate measurement of intraocular pressure (IOP) is fundamental to almost any ophthalmic examination. Dynamic contour tonometry (DCT) was introduced 5 years ago as an entirely novel contact tonometry principle designed to measure IOP largely independently of corneal properties. Since then, many studies have compared the performance of this tonometer to the Goldmann applanation tonometer (GAT) and other tonometers in healthy eyes, as well as eyes with glaucoma or corneal diseases, and after corneal surgery. There is now strong evidence that DCT measures IOP very accurately, with very low inter- and intraobserver variability. This article summarizes the findings of these studies and analyzes the role of DCT in challenging GAT as the gold-standard tonometer for IOP measurements
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