RESUMEN

PURPOSE: To evaluate the diagnostic validity of the HNT-1P non-contact tonometer (Huvitz) as a tool for accurately measuring intraocular pressure (IOP) in patients with healthy eyes, compared to the Goldmann applanation tonometer (GAT), which is the Gold Standard method for measurement of IOP. METHODS: Observational, descriptive, transversal study using 148 eyes of 74 healthy patients without a diagnosis of glaucoma or other ophthalmological diseases. Three measurements of IOP were taken in each eye, using three tonometers: HNT-1P, ICR100, and GAT. The median IOP (quartiles) and mean IOP (SD) its statistical significance were calculated, and comparisons were made between the mean and median IOP values found in three groups: GAT-HNT, GAT-ICR, and HNT-ICR. The difference in mean and median IOP was analyzed in each of the three study groups, and its statistical significance and concordance correlation coefficient (CCC) were calculated. RESULTS: The median IOP with HNT-1P was statistically significantly lower than the median IOP with GAT, (1.1 mmHg, p < 0.001). The median IOP with HNT-1P was also lower than the median IOP with ICR100. As an additional result, the median IOP with GAT was lower than the median IOP with ICR. The CCC was moderate for HNT-ICR (0.72) and low for GAT-HNT and GAT-ICR (0.43 and 0.38, respectively). CONCLUSIONS: HNT-1P (Huvitz) provides statistically significantly lower IOP values than those obtained with GAT. HNT-1P could be used for screening of ocular hypertension in postoperative patients. The IOP measurement obtained with HNT-1P should be confirmed with GAT. HNT-1P yields lower IOP values than those obtained with ICR.

RESUMEN

BACKGROUND: To evaluate the agreement between the Goldman applanation tonometer (GAT), Tono-Pen, and noncontact tonometer (NCT) in the measurement of intraocular pressure (IOP) in pseudophakic children. METHODS: The medical records of nonglaucomatous pseudophakic children between 2009 and 2019 were retrospectively analyzed. A total of 46 eyes of 23 patients operated for bilateral pediatric cataract were included in the study. The patients' mean age was 13.4 ± 4.1 years. Central corneal thickness (CCT) and IOP values measured with the GAT, Tono-Pen, and NCT were recorded. Agreement between the tonometers was evaluated by intraclass correlation coefficients (ICC) and the Bland-Altman method. RESULTS: The mean IOP of the 46 eyes included in the study was measured as 13.7 ± 2.3 mm Hg with the GAT, 16.0 ± 2.3 mm Hg with NCT, and 16.5 ± 2.3 mm Hg with the Tono-Pen (p < 0.001). There is no statistical difference between NCT and Tono-Pen measurements, while GAT measurements were significantly lower than those of the NCT and Tono-pen. ICC values showed fair agreement between NCT and Tono-Pen (ICC = 0.720), whereas there was poor agreement between GAT and NCT (ICC = 0.501) and Tono-pen (ICC = 0.314). CONCLUSIONS: With all devices included in the study, thicker corneas were associated with higher IOP measurements. Although there was moderate agreement between the NCT and Tono-Pen, there was a statistically significant difference in the IOP values provided by the three devices. Our results suggest these devices should not be used interchangeably.

Asunto(s)

RESUMEN

AIM: To access the agreement of intraocular pressure (IOP) values obtained from biomechanically corrected tonometer [Corvis ST (CST)], non-contact tonometer (NCT), and Goldmann applanation tonometer (GAT) in children with NCT measured-IOP (NCT-IOP) values of 22 mm Hg or more, and related factors. METHODS: A total of 51 eyes with NCT-IOP≥22 mm Hg in children aged 7 to 14y were examined and IOP was measured by CST, NCT, and GAT. Based on GAT measured IOP (GAT-IOP), ocular hypertension (OHT) group (≥22 mm Hg, 24 eyes) and the non-OHT group (<22 mm Hg, 27 eyes) were defined. We compared the agreement of the three measurements, i.e., CST measured IOP (CST-IOP), GAT-IOP, and NCT-IOP, and further analyzed the correlation between the differences in tonometry readings, central corneal thickness (CCT), axial length (AL), optic disc rim volume, and age. RESULTS: Compared with the OHT group, thicker CCT, larger rim volume, and higher differences between NCT-IOP and GAT-IOP, were found in the non-OHT group. The differences between CST-IOP and GAT-IOP were lower than the differences between NCT-IOP and GAT-IOP in both groups. The mean differences in CST-IOP and GAT-IOP were 1.26 mm Hg (95% limit of agreement ranged from 0.1 to 2.41 mm Hg, OHT group) and 1.20 mm Hg (95% limit of agreement ranged from -0.5 to 3.00 mm Hg, non-OHT group), and the mean differences in NCT and GAT were 3.90 mm Hg (95% limit of agreement ranged from -0.19 to 9.70 mm Hg, OHT group) and 6.00 mm Hg (95% limit of agreement ranged from 1.50 to 10.50 mm Hg, non-OHT group). The differences between CST-IOP and GAT-IOP were not related to CCT, age, and AL in both groups; while the differences between NCT-IOP and GAT-IOP were related to CCT in the OHT group (r=0.93, P<0.001) and to CCT and AL in the non-OHT group (r=0.66, P<0.001, r=-0.81, P<0.001). CONCLUSION: The accuracy of NCT in the diagnosis of pediatric OHT is low. The agreement of CST-IOP and GAT-IOP was significantly higher in children with and without OHT than in those with NCT-IOP and GAT-IOP. Therefore, CST can be used as a good alternative for IOP measurement in children. The impacts of CCT and AL on NCT measurement need to be fully considered when managing childhood IOP.

RESUMEN

Objectives: The objective of the study is to evaluate the agreement between Goldmann applanation tonometer (GAT) and Easyton transpalpebral tonometer, Tonopen, and Icare in patients with Keratoconus. Methods: This cross-sectional study included 46 eyes of 26 patients with keratoconus. Intraocular pressure (IOP) is measured using easyton, icare, tonopen, and GAT. Measurements were compared and the influences of corneal topographic variables on IOP measurement were evaluated. Bland-Altman plots were used for assessing agreement between different tonometers. Results: The mean age of the participants was 24.08±6.76 (range, 18-47) years (15 males and 11 females). The highest of the mean IOP values measured with different tonometers was obtained with Easyton (12.33±1.65), followed by Tonopen (11.59±2.17), GAT (10.67±1.52), and Icare (10.04±2.33). The mean IOP value measured with Easyton was significantly higher than that measured with GAT (p<0.001). There was no significant difference between GAT and either Tonopen (p=0.154) or Icare measurements (p=0.732). There was no significant difference between Tonopen and Easyton measurements (p=0.421). Icare measurements were correlated with central corneal thickness and keratometric values. GAT measurements were correlated with only Kmax. Thirty-eight (82.6%) of the differences were within the agreement limits (assumed clinically important deviation of up to ±2 mmHg) of GAT and Tonopen, 73.9% (n=34) were within the agreement limits of GAT and Icare, and 78.3% (n=36) were within the agreement limits of GAT and Easyton. Conclusion: Compared with GAT, the gold standard method, Easyton IOP readings were higher, while both Tonopen and Icare readings were similar to GAT. All three tonometers showed acceptable agreement with the GAT, however, Tonopen showed the greatest agreement.

RESUMEN

Purpose: To compare readings of intraocular pressure (IOP) taken with the Goldmann applanation tonometer (GAT), the non-contact tonometer (NCT), and the rebound tonometer (RBT), and to compare their correlation with central corneal thickness (CCT). Methods: This was a prospective, cross-sectional, observational study to which patients above 18 years of age were enrolled. A total of 400 eyes of 200 non-glaucomatous patients underwent IOP recordings using the GAT, NCT, and RBT, and CCT was also noted. Informed consent of the patients was taken. The IOP readings taken via the three methods were compared and correlated with CCT. Paired t test was used to compare the two devices. Simple and multivariate linear regression analyses were used to study the relationship between factors. A P value less than 0.05 was considered significant. Correlation was determined using the Pearson correlation coefficient, and a Bland-Altman graph was plotted. Results: Mean IOP measured by the NCT was 15.65 ± 2.80 mmHg, by the RBT was 14.23 ± 3.05 mmHg, and by the GAT was 14.69 ± 2.97 mmHg. The mean CCT was 510.61 ± 33.83 microns. The difference between mean IOP recorded by the NCT and that by the RBT was 1.41 ± 2.39 mmHg, between the NCT and GAT was 0.95 ± 2.03 mmHg, and between the GAT and RBT was 0.45 ± 2.22 mmHg. The difference between the IOP values was statistically significant (P < 0.005). All tonometers showed a statistically significant correlation with CCT, but it was observed that the NCT had a stronger correlation (0.4037). Conclusion: The IOP readings taken by all the three methods were comparable; however, RBT values were closer to GAT values. CCT did influence the IOP values, and this should be kept in mind while evaluating.

Asunto(s)

RESUMEN

Introduction Glaucoma is characterized by the loss of retinal nerve fiber tissues and the loss of the neuroretinal rim of the optic nerve head is termed glaucomatous optic neuropathy (GON). The early diagnosis of glaucoma requires measurement of intraocular pressure (IOP) by tonometry. The gold standard method widely used in clinical settings to measure IOP is Goldmann applanation tonometry (GAT). Myopia is also considered a risk factor for glaucoma. Population-based and hospital-based evidence suggests that the prevalence of GON is higher in high myopic eyes than in emmetropic eyes. The present study aims to document the association between myopia and elevated IOP. Materials and methods A total of 400 medium and high myopic patients attending the ophthalmology outpatient department, in a tertiary care hospital, were measured for IOP using GAT and underwent a detailed clinical evaluation. All the patients also underwent slit lamp biomicroscopic examination and fundus examination. Other data included details on demographic, socio-economic, and occupational history. Results A detailed refractive error examination revealed that amongst 400 right eyes, 67.5% had medium myopia, while 66.75% of the left eye were medium myopic. Amongst the medium myopic eyes, the average IOP was 15.51±3.68 mm of Hg, while in high myopic, the average IOP was 16.19±3.33 mm of Hg. A difference of 0.68 mm of Hg with high myopic eyes having higher IOP values than medium myopic eyes was observed, and it was significant statistically with a p-value <0.05. Conclusion There is a statistically significant association between elevated IOP and the high myopic group. In comparison to IOP measured in medium myopic and high myopic patients, elevated IOP was observed in the high myopic group than in the medium myopic group.

RESUMEN

BACKGROUND: To evaluate the postoperative outcomes of initial trabeculectomy (Trab) and Ex-PRESS (EX) in terms of achieving an intraocular pressure (IOP) below 15 and 18 mmHg. METHODS: This study retrospectively analyzed 64 and 54 cases of Trab and EX, respectively, performed by the same surgeon with uniform management from April 2018 to March 2019. Surgical success was defined as 5 < IOP < 15 mmHg (criterion 1) and 5 < IOP < 18 mmHg (criterion 2) without additional glaucoma medication, needling, and bleb reconstruction 2 months after surgery. Survival analysis with Cox regression was performed to identify factors associated with postoperative outcomes. RESULTS: The Trab and EX groups had an IOP of 22.6 ± 6.2 vs. 21.8 ± 6.0 mmHg before surgery (P = 0.507), 12.6 ± 2.6 vs. 14.0 ± 4.4 mmHg (P = 0.06) at 6 months, 12.7 ± 2.3 vs. 12.9 ± 2.8 mmHg (P = 0.678) at 12 months, 13.3 ± 2.6 vs. 12.6 ± 2.8 mmHg (P = 0.260) at 18 months, and 13.2 ± 2.3 vs. 13.6 ± 2.8 mmHg (P = 0.444) at 24 months, respectively. The proportion of those with an IOP < 15 mmHg in the Trab and EX groups was 82% vs. 81% at 6 months, 68% vs. 62% at 12 months, 63% vs. 61% at 18 months, and 57% vs. 53% at 24 months, respectively. The log-rank test showed no significant difference between the groups for Criteria 1 (P = 0.755) and 2 (P = 0.138). The results of the multivariate logistic analysis identified only a high preoperative IOP as a risk factor for surgical failure (odds ratio for Criteria 1: 1.076, P = 0.009 and Criteria 2: 1.068, P = 0.048). CONCLUSION: Postoperative outcomes of Trab and EX suggested similar ability for achieving an IOP below 15 and 18 mmHg without medications and interventions.

RESUMEN

PURPOSE: To assess the agreement among four types of intraocular pressure (IOP) measurements: IOP obtained by Goldmann applanation tonometer (IOP-GAT),IOP obtained by an air-puff tonometer (Nidek NT-510)(IOP-NCT), the non-corrected IOP obtained by the Corneal Visualization Scheimpflug Technology (IOP-Corvis) and the biomechanically corrected IOP obtained by the Corvis ST (bIOP-Corvis) in healthy patients with a broad spectrum of IOP values. Methods: This prospective, observational study recruited 113 healthy individuals. Each patient underwent IOP evaluation via GAT, Nidek NT-510 and Corvis ST. Difference in mean in IOP readings was assessed by one-way repeated-measures analysis of variance (ANOVA).Tonometer intermethod agreement was assessed by the Bland-Altman method. The difference between the four IOP measurements was correlated against corneal (CCT) and age with Pearson's correlation test. Results: IOP-Corvis showed the highest values (16.59 ± 3.08 mmHg),followed by IOP-NCT (16.05 ± 3.43 mmHg), IOP-GAT (15.62 ± 3.08 mmHg) and bIOP-Corvis (15.10 ± 2.67 mmHg).There were statistically significant differences in IOP measurements among all the ANOVA pairwise comparisons except between IOP-GAT and bIOP-Corvis (p = 0.07),as well as between IOP-GAT and IOP-NCT (p = 0.25). Bland Altman analysis revealed a notable bias (all p < 0.05) among IOP-GAT and bIOP-Corvis, IOP-GAT and IOP-Corvis, IOP-GAT and IOP-NCT, bIOP-Corvis and IOP-Corvis, bIOP-Corvis and IOP-NCT,IOP-Corvis and IOP-NCT of 0.51, -0.97, -0.43, -1.49, -0.95, 0.53 mmHg respectively. We observed a strong correlation of the difference between bIOP-Corvis and IOP-Corvis with CCT and patient age. Conclusion: Compared with GAT and Nidek NT-510, the Corvis-derived IOPs were recorded either the highest as IOP-Corvis or the lowest as bIOP-Corvis. Even if the differences among the tonometers were relatively small, the IOP values obtained with the Corvis ST, NCT and GAT were not interchangeable.

RESUMEN

This study aimed to compare intraocular pressures (IOP) using different tonometers, Goldmann applanation (IOPGAT), non-contact (IOPNCT), and rebound (IOPRBT), and to assess the effects of aging and central corneal thickness (CCT) on the measurements. The IOPGAT, IOPNCT, IOPRBT, mean patient age (65.1 ± 16.2 years), and CCT (521.7 ± 39.2 µm) were collected retrospectively from 1054 eyes. The differences among IOPs were compared by the paired t-test. Possible correlations between devices, age, and CCT were assessed by linear regression analyses. The effects of age and CCT on the IOP reading were assessed by mixed-effects regression models. The IOPGAT values were 2.4 and 1.4 mmHg higher than IOPNCT and IOPRBT, respectively; the IOPNCT was 1.0 mmHg lower than IOPRBT (p < 0.0001 for all comparisons). The IOPs measured by each tonometer were highly correlated with each other (r = 0.81-0.90, t = 45.2-65.5). The linear regression analyses showed that age was negatively correlated with IOPNCT (r = -0.12, t = -4.0) and IOPRBT (r = -0.14, t = -4.5) but not IOPGAT (r = 0.00, t = -0.2); the CCT was positively correlated with IOPGAT (r = 0.13, t = 4.3), IOPNCT (r = 0.29, t = 9.8), and IOPRBT (r = 0.22, t = 7.2). The mixed-effect regression models showed significant negative correlations between age and IOPNCT (t = -2.6) and IOPRBT (t = -3.4), no correlation between age and IOPGAT (t = 0.2), and a significant positive correlation between CCT and the tonometers (t = 3.4-7.3). No differences between IOPGAT and IOPRBT were seen at the age of 38.8 years. CCT affects IOPs from all tonometers; age affects IOPNCT and IOPRBT in different degrees. IOPRBT tended to be higher than IOPGAT in young subjects, but this stabilized in middle age and became higher in older subjects.

RESUMEN

Intraocular pressure (IOP) is an important measurement that needs to be taken during ophthalmic examinations, especially in ocular hypertension subjects, glaucoma patients and in patients with risk factors for developing glaucoma. The gold standard technique in measuring IOP is still Goldmann applanation tonometry (GAT); however, this procedure requires local anesthetics, can be difficult in patients with scarce compliance, surgical patients and children, and is influenced by several corneal parameters. Numerous tonometers have been proposed in the past to address the problems related to GAT. The authors review the various devices currently in use for the measurement of intraocular pressure (IOP), highlighting the main advantages and limits of the various tools. The continuous monitoring of IOP, which is still under evaluation, will be an important step for a more complete and reliable management of patients affected by glaucoma.

RESUMEN

BACKGROUND: This study investigated the agreement between a new rebound tonometer, IC200, and IcarePRO and Goldmann applanation tonometry (GAT). METHODS: This was a prospective cross-sectional study. We measured the intraocular pressure (IOP) in 145 eyes of 145 glaucoma patients in the sitting position using GAT, IcarePRO, and IC200. IcarePRO and IC200 measurements were also obtained in the supine position. IC200 measurement was performed using two modes: single six (IC200-single) and automatic (IC200-continuous) six-measurements mode. RESULTS: All tonometers provided high reproducibility in both positions (all intraclass correlation coefficients > 0.90), although it was highest with GAT, followed by IC200-continuous and IC200-single and then IcarePRO. In the sitting position, the mean (± SD) IOPs of GAT, IcarePRO, IC200-single, and IC200-continuous were 14.5 ± 2.9 mmHg, 13.3 ± 3.2 mmHg, 11.6 ± 3.2 mmHg, and 11.5 ± 3.2 mmHg, respectively. IOPs measured with IcarePRO or IC200 were significantly lower than those with GAT, particularly in patients with low IOP. IOPs measured with all tonometers were significantly elevated in the supine position as compared with the sitting position, but this difference was significantly greater with IC200-single and IC200-continuous compared with IcarePRO. IOP elevation was significant in eyes without bleb versus those with bleb, but this finding was not observed when IOP was measured with IcarePRO. The IOPs of the single and continuous modes of IC200 were interchangeable in both positions. CONCLUSIONS: GAT, IcarePRO, and IC200 had sufficiently high reproducibility, but measurements with IcarePRO may not be accurate in the supine position. Elevation of IOP in the supine position, especially in eyes with bleb, was more sensitively captured with IC200 than with IcarePRO. TRIAL REGISTRATION: Japan Clinical Trials Register, No. UMIN000039982 .

RESUMEN

PURPOSE: To study the agreement between the Icare ic200 (ICare Finland Oy, Helsinki, Finland) and the Goldmann Applanation Tonometer (GAT) in the measurement of intraocular pressure (IOP) in adult eyes. DESIGN: Noninterventional, cross-sectional study. PARTICIPANTS: A total of 156 eyes of 156 adult participants with clear corneas were included. METHODS: The IOP measurements were obtained with the Icare ic200 by 1 observer followed by GAT readings by a second masked observer. The central corneal thickness (CCT) and biometry of all subjects were recorded. MAIN OUTCOME MEASURES: The agreement between Icare ic200 and GAT was measured using the Bland-Altman plot. RESULTS: The mean age ± standard deviation of subjects was 55.3 ± 13.7 years. The GAT IOP ranged from 6 to 50 mmHg with a mean IOP of 19.5 ± 8.8 mmHg. The Icare ic200 IOP ranged from 7.4 to 50 mmHg with a mean IOP of 20.8 ± 9.3 mmHg. The mean difference between the IOP measurement of GAT and Icare ic200 was -1.27 mmHg with the 95% limits of agreement (LoA) ranging from -3.4 to 0.9 mmHg for all ranges of IOP. The mean difference (95% LoA) between the IOP measurement of GAT and Icare ic200 was -1 mmHg (-3 to 1 mmHg) and -1.8 mmHg (-4 to 0.2 mmHg) for a GAT IOP ≤21 mmHg and >21 mmHg, respectively. The CCT, axial length, age, and gender did not significantly affect the difference in measurement of IOP between the 2 tonometers. However, for every 1-mmHg increase in GAT IOP, the difference between the 2 tonometers increased by 0.04 mmHg (P < 0.001). CONCLUSIONS: In our study, the Icare ic200 overestimated the IOP. The overestimation increased as the baseline IOP increased. The agreement between the IOP measurement by GAT and Icare ic200 was <2 mmHg at all ranges of IOP. The narrow LoA between the tonometers for an IOP <21 mmHg makes it a useful alternative to GAT in this pressure range.

Asunto(s)

RESUMEN

BACKGROUND: Measurement of intraocular pressure (IOP) forms a crucial component in the diagnosis and management of glaucoma. Many devices have been developed to measure IOP with Goldmann applanation tonometry (GAT) considered the gold standard for IOP measurement. OBJECTIVES: The objective was to compare the IOP measured using Icare ic100 and GAT. METHODS: This cross-sectional study measured IOP in 1,000 eyes (500 left and 500 right) using the Icare ic100 and GAT. Central corneal thickness (CCT) was measured using a hand-held pachymeter. IOP measurements were investigated in all eyes, by IOP substrata, by CCT group, by number of topical glaucoma medications, and diagnosis. RESULTS: There was moderate agreement between ic100 and GAT IOP measurements (intraclass correlation coefficient 0.73). Mean IOP was significantly lower when measured by ic100 than by GAT (12.1 vs. 16.2 mm Hg, p < 0.0001). Mean ic100 IOPs were also significantly lower than mean GAT IOPs within each IOP strata ≤12 (7.9 vs. 9.7 mm Hg, p < 0.0001), 13-21 (12.1 vs. 16.6 mm Hg, p < 0.0001), and ≥22 (18.4 vs. 25.2 mm Hg, p < 0.0001) and within each subanalysis. CONCLUSIONS: The Icare tonometer consistently under estimated IOP compared to GAT, irrespective of CCT ranges and other subgroup analyses. The mean difference of 4.2 mm Hg can have significant clinical implications, particularly in the management of glaucoma patients.

Asunto(s)

RESUMEN

PURPOSE: To study the agreement between the Icare ic200 (ICare Finland Oy, Helsinki, Finland) and the Goldmann Applanation Tonometer (GAT) in the measurement of intraocular pressure (IOP) in adult eyes. DESIGN: Noninterventional, cross-sectional study. PARTICIPANTS: A total of 156 eyes of 156 adult participants with clear corneas were included. METHODS: The IOP measurements were obtained with the Icare ic200 by 1 observer followed by GAT readings by a second masked observer. The central corneal thickness (CCT) and biometry of all subjects were recorded. MAIN OUTCOME MEASURES: The agreement between Icare ic200 and GAT was measured using the Bland-Altman plot. RESULTS: The mean age ± standard deviation of subjects was 55.3 ± 13.7 years. The GAT IOP ranged from 6 to 50 mmHg with a mean IOP of 19.5 ± 8.8 mmHg. The Icare ic200 IOP ranged from 7.4 to 50 mmHg with a mean IOP of 20.8 ± 9.3 mmHg. The mean difference between the IOP measurement of GAT and Icare ic200 was -1.27 mmHg with the 95% limits of agreement (LoA) ranging from -3.4 to 0.9 mmHg for all ranges of IOP. The mean difference (95% LoA) between the IOP measurement of GAT and Icare ic200 was -1 mmHg (-3 to 1 mmHg) and -1.8 mmHg (-4 to 0.2 mmHg) for a GAT IOP ≤21 mmHg and >21 mmHg, respectively. The CCT, axial length, age, and gender did not significantly affect the difference in measurement of IOP between the 2 tonometers. However, for every 1-mmHg increase in GAT IOP, the difference between the 2 tonometers increased by 0.04 mmHg (P < 0.001). CONCLUSIONS: In our study, the Icare ic200 overestimated the IOP. The overestimation increased as the baseline IOP increased. The agreement between the IOP measurement by GAT and Icare ic200 was <2 mmHg at all ranges of IOP. The narrow LoA between the tonometers for an IOP <21 mmHg makes it a useful alternative to GAT in this pressure range.

Asunto(s)

RESUMEN

OBJECTIVES: To determine the accuracy and precision of the Icare® TONOVET Plus rebound tonometer and the Tono-Pen AVIA Vet™ applanation tonometer for intraocular pressure (IOP) measurement in normal ex vivo canine eyes and comparison to earlier models of these tonometers. ANIMALS & PROCEDURES: The anterior chambers of six normal dog eyes were cannulated ex vivo. IOP was measured with the TONOVET (TV01), TONOVET Plus, Tono-Pen Vet™, and Tono-Pen AVIA Vet™ at manometric IOPs ranging from 5 to 70 mm Hg. Data were analyzed by linear regression, ANOVA and Bland-Altman plots. A P value ≤ .05 was considered significant. RESULTS: Intraocular pressure values obtained using the TONOVET Plus and TV01 were significantly more accurate than with the Tono-Pen VET and Tono-Pen AVIA Vet, particularly at higher IOPs (30-70 mm Hg). Accuracy was not significantly different between any of the devices in the low to normal physiologic IOP range (5-25 mm Hg). Level of precision was high for all devices, though the TONOVET Plus was more precise than the Tono-Pen Vet in the 5-25 mmHg range and the TV01 was more precise than the Tono-Pen AVIA Vet over the whole IOP range. CONCLUSIONS: All devices underestimated IOP, particularly at higher pressures. Rebound tonometers were more accurate over the full range of IOP tested and in the high IOP range; however, there were no significant differences in accuracy among devices in the physiologic IOP range. All tonometers can provide clinically useful IOP readings in dogs, but rebound and applanation tonometers should not be used interchangeably.

Asunto(s)

RESUMEN

PURPOSE: The aim of this study was to compare the measurements of intraocular pressure by two tonometers, the Icare rebound tonometer and the Goldmann applanation tonometer, in a randomised screening study. The influence of refraction and central corneal thickness on the measurements was also evaluated. METHODS: Intraocular pressure was measured with rebound tonometer and Goldmann applanation tonometer in 1266 participants; refraction and central corneal thickness were also determined. One randomised eye of each participant was selected for this report's analysis. A Bland-Altman plot was used to compare the values obtained with the two devices. RESULTS: The correlation between rebound tonometer and Goldmann applanation tonometer was good: the intraclass correlation coefficient (r) between the two methods was 0.735 (p < 0.001). The mean difference (rebound tonometer-Goldmann applanation tonometer) was 0.11 ± 2.3 mmHg. The difference was not statistically significant (95% confidence interval: 0.11 to 0.13, p = 0.09). With increasing central corneal thickness, not only did intraocular pressure values with both devices increase, but the difference between them also increased. Refraction (spherical equivalent) did not influence intraocular pressure or the rebound tonometer-Goldmann applanation tonometer difference. However, high astigmatism (≥2D) exerted an influence on intraocular pressure values taken with Goldmann applanation tonometer. CONCLUSION: Measurements with rebound tonometer and Goldmann applanation tonometer are relatively uniform although rebound tonometer slightly overestimated intraocular pressure. Both rebound tonometer and Goldmann applanation tonometer and the difference between these devices were affected by central corneal thickness but not by refraction. Higher astigmatism affected Goldmann applanation tonometer more than rebound tonometer. It is concluded that rebound tonometer is a reliable method for measuring intraocular pressure in a population-based screening study.

Asunto(s)

RESUMEN

Purpose: To compare corrected intraocular pressure (IOP) by tonopachy with that of Goldmann applanation tonometry (GAT) in normal and glaucomatous patients. Methods: In this cross-sectional study, IOP and central corneal thickness (CCT) were measured in 426 eyes (213 normal eyes and 213 glaucomatous eyes) of 426 patients by tonopachy followed by GAT and ultrasound pachymetry. IOP was corrected for CCT by in-built formula in tonopachy and Ehlers correction factor for Goldmann tonometer. Limits of agreements were assessed using Bland-Altman plots. Intraclass correlation coefficient was calculated to estimate the absolute agreement between single and average measurements of IOP and CCT of tonopachy with that of Goldmann tonometer and ultrasound pachymetry respectively. Results: Mean corrected IOP measured with tonopachy and GAT in glaucomatous eyes was 17.63 ± 5.04 mmHg and 19.42 ± 5.83 mmHg, and in controls it was 13.4 ± 2.5 mmHg and 16.2 ± 3.1 mmHg, respectively. Limits of agreement ranged from -4.63 to +9.25 mmHg for total population (mean = 2.31), -6.01 to +9.59 mmHg (mean = 1.79) for glaucoma group and -2.99 to +8.65 mmHg (mean = 2.83) for controls. Intraclass correlation coefficient for IOP measurement between tonopachy and Goldmann tonometer was 0.84 for total population, 0.85 for glaucoma group, and 0.63 for controls, respectively. Conclusion: Corrected IOP obtained by tonopachy showed moderate agreement with GAT and it is more in glaucoma patients than controls. Thus, tonopachy can be used as a screening tool, but cannot replace GAT.

Asunto(s)

RESUMEN

BACKGROUND: Accurate measurement of intraocular pressure (IOP) after corneal refractive surgery is of great significance to clinic, and comparisons among various IOP measuring instruments are not rare, but there is a lack of unified analysis. Although Goldmann Applanation Tonometer (GAT) is currently the internationally recognized gold standard for IOP measurement, its results are severely affected by central corneal thickness (CCT). Ocular Response Analyzer (ORA) takes certain biomechanical properties of cornea into account and is supposed to be less dependent of CCT. In this study, we conducted the meta-analysis to systematically assess the differences and similarities of IOP values measured by ORA and GAT in patients after corneal refractive surgery from the perspective of evidence-based medicine. METHODS: The authors searched electronic databases (MEDLINE, EMBASE, Web of science, Cochrane library and Chinese electronic databases of CNKI and Wanfang) from Jan. 2005 to Jan. 2019, studies describing IOP comparisons measured by GAT and ORA after corneal refractive surgery were included. Quality assessment, subgroup analysis, meta-regression analysis and publication bias analysis were applied in succession. RESULTS: Among the 273 literatures initially retrieved, 8 literatures (13 groups of data) with a total of 724 eyes were included in the meta-analysis, and all of which were English literatures. In the pooled analysis, the weighted mean difference (WMD) between IOPcc and IOPGAT was 2.67 mmHg (95% CI: 2.20~3.14 mmHg, p < 0.0001), the WMD between IOPg and IOPGAT was - 0.27 mmHg (95% CI: - 0.70~0.16 mmHg, p = 0.2174). In the subgroup analysis of postoperative IOPcc and IOPGAT, the heterogeneity among the data on surgical procedure was zero, while the heterogeneity of other subgroups was still more than 50%. The comparison of the mean difference of pre- and post-operative IOP (∆IOP) was: mean-∆IOPg > mean-∆IOPGAT > mean-∆IOPcc. CONCLUSIONS: IOPcc, which is less dependent on CCT, may be more close to the true IOP after corneal refractive surgery compared with IOPg and IOPGAT, and the recovery of IOPcc after corneal surface refractive surgery may be more stable than that after lamellar refractive surgery.

Asunto(s)

RESUMEN

BACKGROUND: The aim of this study was to determine whether Central Corneal Thickness (CCT) is associated with intraocular pressure measurement (IOP) with a Non-contact tonometer and the Goldmann applanation tonometer in glaucoma patients. MATERIALS AND METHODS: The study involved two hundred and thirty-two eyes of clinically diagnosed glaucoma patients receiving care at a referral facility. IOP measurements were obtained using both the Non-Contact Tonometer (NCT) and Goldmann Applanation Tonometer (GAT). The association between age, ethnicity, and CCT, as well as CCT on the measures of NCT and GAT, were analyzed. RESULTS: There were 64(55.2%) males and 52 (44.8%) females and their ages ranged from 18 to 85 years (mean age = 47.72; SD ± 15.75 years). There was a weak positive correlation between the CCT and NCT findings in the right eye (r = 0.19, n = 116, p < 0.05) and in the left eye (r = 0.25, n = 116, p < 0.05). However, there was no correlation between CCT and GAT measurements. Age had a significant correlation with CCT while gender and ethnicity had no significant correlation. CONCLUSION: The study found a significant association between CCT and NCT. However, there was no significant association between CCT and GAT. CCT had an association with age but independent of gender and ethnicity since there was no significant relationship between these variables.

Asunto(s)

RESUMEN

OBJECTIVES: The objective of the study was to explore the usage of the Goldmann applanation tonometry and noncontact tonometry interchangeably in the measurement of intraocular pressure (IOP) in glaucoma patients. MATERIALS AND METHODS: The study involved 441 clinically diagnosed glaucoma patients receiving care at a referral facility. IOP measurements were obtained using both the Noncontact tonometer and Goldmann applanation tonometer The repeatability of the measures was analyzed by comparing the repeated measures of the devices using paired t-test and calculating the correlation coefficient. A Bland-Altman analysis was used to determine the limits of agreement between the two procedures. RESULTS: There were 271 (61.5%) males and 170 (38.5%) females and their age ranged from 18 to 73 years (mean age = 49.37; standard deviation ± 14.81 years). The findings of the study showed significantly lower readings (P < 0.001) of the GAT (right eye = 17.40 ± 7.48 mmHg; left eye = 16.80 ± 7.49 mmHg) compared to the NCT (right eye = 20.15 ± 8.30 mmHg; left eye = 19.74 ± 8.31 mmHg). There was a strong positive correlation between the GAT and NCT findings in the right eye (r = 0.871, n = 441, P < 0.001) and in the left eye (r = 0.887, n = 441, P < 0.001). There was a wide limit of agreement between NCT and GAT measurements. CONCLUSION: There was statistically significant higher measures obtained with NCT than the GAT but did not exceed the allowable inter-device difference. There was a strong positive correlation between GAT and NCT measurements. However, it is strongly recommended that these devices are not used interchangeably in the monitoring of IOP in glaucoma due to the wide range of limits of agreement.