Assessment of intraocular pressure measurement between Goldman applanation tonometer, rebound tonometer, non-contact tonometer, and its correlation with central corneal thickness

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.

CLINICAL EVALUATION OF INTRAOCULAR PRESSURE MEASUREMENTS USING DIFFERENT TONOMETERS IN PATIENTS OF VARIOUS REFRACTIVE ERRORS

Background: Intraocular pressure (IOP)is an important ?rst indicator of probability and suspicion of Glaucoma. The virtual IOP status is grossly in?uenced by multiple factors including Refractive errors ,corneal biomechanics ,central corneal thickness(CCT) and Scleral rigidity. To compare relative IOP measurements and Aim: its variability in Emmetropes, myopic and hypermetropic patients using Schiotz, Goldmann Applanation(GAT)and I-Care Rebound tonometer to establish an equation between virtual and real time IOP. This observational Materials and Methods: prospective study comprised of 100 subjects above the age of 18 years inclusive37 Emmetropes , 31 Hypermetropes and remaining 32 belonged to myopia . Descriptive statistics were performed using SPSS for Windows Statistical Analysis : version 17.0 to calculate the demographic characteristics of the study cohort. The data were expressed as mean values including the standard deviation (SD) and the 95% con?dence interval (CI). Mean IOP measurements between Schiotz, I-Care and GAT were compared by One way ANOVA along with Individual pair wise comparison by applying Post Hoc Tukey Test for comparison of IOP measurements using a particular method of Tonometry in individuals of myopia, hypermetropia and emmetropia. The highest mean value of CCT 536.667 mum was in Hypermetropes whereas the lowest CCT value of Results: 507.031mum was in myopic eyes with statistically signi?cant (P<0.05). The mean value for IOP in Emmetropes was16.665 mm Hg for Schiotz , 15.027 Hg for GAT and 15.081 mm Hg for I –Care .Whereas Hypermetropes revealed mean value of 15.055 mm Hg for Schiotz , 14.323 mm Hg for GAT and 14.065 mm Hg for I –Care . The mean value for IOP in Myopic eyes was 16.875 mm Hg for Schiotz , 14.375 mm Hg for GAT and 14.688 mm Hg for I –Care . The study had revealed higher mean Conclusion : value of IOP in Myopic eyes as compare to Emetropic and Hypermetropic subjects.IOP measurements by the Schiotz tonometer were signi?cantly higher as compare to GAT and I-Care tonometer. Whereas recordings by GAT and I Care tonometers were almost in agreement .De?nitive correlation could not be established between pachymetry readings and adjusted IOP following GAT and I –Care tonometry .

The Difference in Intraocular Pressure before and after Visual Field Test Measured by Rebound Tonometer

PURPOSE: To investigate the effect of a visual field (VF) test on intraocular pressure (IOP) and relevant parameters in a normal group and an open-angle glaucoma group, and to determine the appropriate time of IOP measurements.METHODS: The IOP was measured by a rebound tonometer before and after a VF test for the normal, normal-tension glaucoma, and high-tension glaucoma groups, and IOP differences after the VF tests were compared among groups. Parameters including age, sex, axial length, central corneal thickness, IOP before the VF test, the VF index, mean deviation, VF test duration, and usage of IOP lowering medications were investigated, and the correlations of these parameters with IOP changes after VF tests were determined using linear regression analyses.RESULTS: A total of 232 participants (232 eyes) included 55 normal subjects, 131 normal-tension glaucoma patients, and 46 high-tension glaucoma patients. The IOP differences after VF tests were not statistically significant in the normal and high-tension glaucoma groups, and the difference was 0.31 mmHg in the normal-tension glaucoma group (p = 0.013). Multivariate regression analyses revealed that axial length (p = 0.005) and IOP before the VF test (p < 0.001) were relevant factors in the total number of patients, and the axial length (p = 0.017), IOP before the VF test (p = 0.001), and duration (p = 0.029) were found to be significantly associated with IOP differences in the normal-tension glaucoma group.CONCLUSIONS: The IOP changes after VF tests using the rebound tonometer were significant in the normal-tension glaucoma group, but were within an acceptable range. The IOP value measured after a VF test is clinically valid in clinical practice.

Accuracy of intraocular pressure measurements between non-contact tonometer and ICare rebound tonometer / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To analyze the accuracy of non-contact tonometer(NCT)and ICare rebound tonometer(RBT)in measuring intraocular pressure in glaucoma patients. <p>METHODS:A retrospective proportional control study. Totally 113 patients(185 eyes)with glaucoma were studied. Intraocular pressure was measured by RBT, NCT and Goldmann Applanation tonometer(GAT)at 9:00 and 16:00 and recorded as two sets of data, respectively. Their accuracy is evaluated by the rank sum test, and the international standard 8621 guide, Bland-Altman consistency analysis analyzed the consistency of the two groups of measurements, and the data were divided into two groups: abnormal intraocular pressure group(<10mmHg or >21mmHg)and normal intraocular pressure group(10-21mmHg). The consistency was analyzed between different groups. The spearman correlation analysis is adopted to analyze the correlation between ophthalmotonometers.<p>RESULTS: There were differences among the GAT, NCT and RBT measurements(<i>P</i><0.01). There was a strong correlation between the intraocular pressure measured value obtained by GAT and measured values obtained by RBT and NCT(<i>rs</i>=0.71, 0.77, <i>P</i><0.001). The measured values of NCT and GAT are close to each other without statistically significant differences(<i>P</i>=0.92). Compared with GAT, RBT has a higher intraocular pressure measured value, and there are significant differences(<i>P</i><0.05). However, compared with GAT, both NCT and RBT have a wide range of limits of agreement, and they are(-6.2-6.0mmHg)and(-5.2-7.6mmHg)respectively. In normal intraocular pressure groups, the ranges of limits of agreement are(-5.9-5.9mmHg)and(-4.3-7.5mmHg)respectively. In abnormal intraocular pressure groups, the ranges of limits of agreement are(-7.3-6.4mmHg)and(-7.5-5.6mmHg)respectively. The evaluation carried out in accordance with ISO 8612 guides indicates that the abnormal values more than the 95% of consistency restriction of NCT and RBT in the three groups are(3.9%, 11.3%, 12.2%)and(26.3%, 11.3%, 12.2%)respectively.<p>CONCLUSION: Both NCT and RBT cannot simply replace the GAT to measure the intraocular pressure of glaucoma patients. In glaucoma patients, with the deviation of the measured value from the normal intraocular pressure range, the measurement error of NCT and RBT also increase.

Rebound Tonometers versus Other Tonometers: Agreement among Readings and the Effects of Axial Length, Ocular Pulse Amplitude, and Central Corneal Thickness on Readings

OBJECTIVE: The aim of this study was to use intraocular pressure (IOP) measurements obtained via rebound tonometry (RBT, the I-care instrument), Goldmann applanation tonometry (GAT), non-contact tonometry (NCT), dynamic contour tonometry (DCT, PASCAL), and the TonoPen to investigate the consistency of readings among methods and the influence of ocular pulse amplitude (OPA), axial length (AL), and central corneal thickness (CCT) on RBT data. METHODS: We prospectively studied 123 eyes. IOP was measured via RBT, GAT, NCT, DCT, and the TonoPen. In addition, OPA was measured via DCT, AL, and CCT. Correlations among measurements using the various methods were evaluated, as were the effects of OPA, AL, and CCT on RBT data. RESULTS: RBT data were significantly correlated with data obtained via GAT, NCT, DCT, and the TonoPen; the highest correlation was with GAT. OPA was significantly correlated with IOP measured via GAT but not with IOP measured via RBT. Both AL and CCT were significantly correlated with IOP data obtained via RBT and GAT. CONCLUSION: Significant correlations were evident among IOP measurements obtained via RBT and other tonometry methods. However, the influence of AL and CCT on IOP measurements obtained via RBT requires careful consideration and interpretation. Although the IOP values obtained by GAT were correlated with OPA values obtained by DCT, this was not true of IOP data obtained by RBT. This might be associated with characteristic of RBT which has the relatively short corneal contact time.

Can higher end tonometers be used interchangeably in routine clinical practice.

Context: Precise intraocular pressure (IOP) measurement is important in glaucoma practise. Various instruments are available today to accurately measure IOP. Thus, the question arises about which instrument to use and whether all of them can be used interchangeably. Aims: To assess the agreement between noncontact tonometer (NCT), rebound tonometer (RBT), Goldmann applanation tonometer (GAT), and dynamic contour tonometer (DCT) in measuring IOP. Subjects and Methods: 499 eyes of 250 patients were evaluated during a period of 24 months from September 2010 to August 2012 and measurement of IOP by NCT, RBT, GAT, and DCT was done in the given sequence. The agreement was assessed by use of the Bland–Altman plot keeping GAT as a gold standard technique. Results: The mean IOP value of NCT, RBT, GAT, and DCT was 15.9 ± 5.5, 15.9 ± 5.8, 15.9 ± 4.9, and 16.0 ± 4.7 mm of Hg, respectively. The limits of agreement of GAT with DCT, NCT, and RBT were found to be +5.4 to −5.2, −4.7 to +4.6, and −5.2 to +5.1 mm of Hg, respectively. Conclusions: A positive and strong correlation was found between newer tonometers and GAT, but the limit of agreement was clinically unacceptable. The use of a single tonometer should be practised at a glaucoma clinic for a patient at each follow‑up.

Accuracy and Reliability of the Icare PRO in Enucleated Porcine Eyes - Upright and Horizontal Positions

PURPOSE: To compare the accuracy and reliability of intraocular pressure (IOP) measurements in enucleated porcine eyes using the Icare PRO in the upright and horizontal positions. METHODS: We designed an enucleated porcine eye model whose anterior chamber was cannulated with a 30-gauge needle, connected in parallel to a pneumatic pressure device. The reference pressure was manipulated by changing the air pressure from 70 to 10 mm Hg at 10 mm Hg intervals, and the IOP of porcine eyes was measured with the Icare PRO at each pressure. Correlation analysis, comparison using the Bland-Altman plot and Wilcoxon signed rank test, was performed to assess the accuracy of IOP measurements. Intraclass correlation coefficients were calculated to assess the intra-observer variability in the upright and horizontal positions, respectively. RESULTS: The IOP value in both upright and horizontal positions was well correlated with the reference pressure (r = 0.992 and 0.985, respectively). The Bland-Altman plot showed good agreement between the two positions. However, all IOP values in both positions were lower than the reference pressures. The IOP values in the horizontal position were significantly lower than those in the upright position at the a reference pressure of 50 mm Hg or greater. Values of intraclass correlation coefficient ranged from 0.911 to 0.984 when measured in the upright position and from 0.707 to 0.914 in the horizontal position. CONCLUSIONS: IOP measurements of Icare PRO in porcine eyes were remarkably lower than reference pressures controlled by the pneumatic method even though they showed a good correlation with reference values. The higher was the reference pressure, the greater was the degree of underestimation of IOP measurement in both positions. This trend was more pronounced in the horizontal position, and the reliability of IOP measurements was also lower than that in the upright position.

Reliability Comparison of Rebound Tonometer at the Upright and Supine Position

PURPOSE: Rebound tonometer has been used to measure the intraocular pressure (IOP) in the supine as well as normal upright positions. We investigated the reliability of IOP measurements using the rebound tonometer in the upright and supine positions. METHODS: IOP was measured in 30 patients (60 eyes) with open-angle glaucoma who had no history of ocular surgery and no anterior segment pathology, in both the upright and supine positions using rebound tonometer (IcarePRO; Icare Finland Oy, Finland). The average IOP value after 6 measurements was recorded. We measured IOP repeatedly until 3 reliable values within normal limits of the measurement's variation were obtained. We calculated the intraclass correlation coefficient (ICC), coefficient of variation, and number of repeated measurements necessary to obtain 3 reliable IOP values in each position as measured by one examiner. RESULTS: ICC values for IOP measurements were 0.852 (95% confidence interval [CI], 0.784-0.903; p < 0.001) in the upright position and 0.684 (95% CI, 0.563-0.784; p < 0.027) in the supine position. Coefficient of variation was 8.7 +/- 0.1% in the upright position and 24.0 +/- 0.1% in the supine position. An average of 3.3 times of repeated measurements in the upright position and 6.2 times in the supine position were necessary to obtain 3 reliable IOP values within the normal range of standard deviation. CONCLUSIONS: When measuring IOP using the IcarePRO rebound tonometer, the measurement reliability was different between the upright and supine positions. Reproducibility of IOP measurements was lower in the upright than the supine position.

Comparison of Rebound Tonometry and Goldmann Applanation Tonometry in Restrictive Thyroid Eye Disease

PURPOSE: To compare the intraocular pressure (IOP) measured using the rebound tonometer (RT) and Goldmann applanation tonometer (GAT) in the primary position and upgaze in restrictive thyroid eye disease (TED). METHODS: We measured the IOP in 30 subjects (54 eyes) who visited an ophthalmologist between May 2014 and May 2015. This study included 16 healthy volunteers (32 eyes) and 14 TED patients (22 eyes). The outcome measurements were the comparison of IOP readings; both intergroup and 2 measurements using the RT and the GAT for patients with restrictive TED and the control group. Upgaze IOP was measured on the central cornea with a 20-degree chin-down posture. RESULTS: Both TED patients and controls showed an increase in IOP in upgaze compared with primary position (p < 0.001). There was a significant difference in mean differential IOP between patients and controls measured using RT and GAT, respectively (p < 0.001). In the control group, there was no significant difference between the 2 instrument readings in upgaze as well as primary position for patients with restrictive TED (p = 0.853 in TED; p = 0.260 in controls). CONCLUSIONS: Based on our results, the mean IOP in conventional upgaze was significantly increased in TED patients compared to primary position using both the RT and GAT and no difference in RT readings compared with GAT readings. The RT can be used to establish IOP since no significant difference between the upgaze and the primary position readings was observed in patients with restrictive TED and is a simple and effective diagnostic tool unrelated to the position and the direction of gaze.

Comparison of Intraocular Pressures According to Position Using Icare Rebound Tonometer

PURPOSE: To evaluate changes in intraocular pressure (IOP) according to position using a portable rebound tonometer. METHODS: We measured the IOP values of 20 healthy volunteers (40 eyes) in the sitting, supine, right lateral decubitus and left decubitus positions with a portable rebound tonometer, and then analyzed using the Wilcoxon signed rank test. IOP in sitting position was also measured with a non-contact tonometer and a Goldmann applanation tonometer, and analyzed with Kruskal-Wallis test and Spearman correlation analysis. Agreement among the 3 tonometers was calculated using the Bland-Altman method. RESULTS: The IOP measured with rebound tonometer in the supine position was significantly higher than in the sitting position (p = 0.002). However, there was no significant difference in IOP between the supine and decubitus positions. In the decubitus position, there was no significant difference in IOP between the dependent and non-dependent eyes. IOP measurement using the rebound tonometer showed positive correlation with that of the noncontact and Goldmann applanation tonometers. CONCLUSIONS: In normal subjects, IOP measurement obtained with a rebound tonometer in the supine position was significantly higher than in the sitting position, but there was no significant difference in IOP between the supine and decubitus positions. A rebound tonometer may be useful for patients whose intraocular pressure measurement with Goldmann applanation tonometer or non-contact tonometer is impossible. When using a portable rebound tonometer in bed-ridden or pediatric patients, we should pay attention to the interpretation of IOP in the supine position.

Comparison of Portable Tonometers and Goldmann Applanation Tonometer for Intraocular Pressure Measurement

PURPOSE: To compare the intraocular pressure (IOP) measured by portable rebound tonometer and TonoPen applanation tonometer with pressure measured by Goldmann applanation tonometer (GAT) and analyze the factors affecting IOP disagreement between tonometers. METHODS: In a prospective study of 463 eyes, IOP was measured with Icare Pro(R) rebound tonometer, TonoPen AVIA(R) applanation tonometer, and GAT. Bland-Altman plot, intraclass correlation coefficient, Pearson's correlation analysis, and multiple regression analysis were performed to evaluate the agreement of IOP measured by each tonometer and the factors affecting the measurements. RESULTS: The IOP values measured by Icare Pro(R) and TonoPen AVIA(R) were consistently higher than those measured by GAT, but showed no significant differences with those measured by GAT (p = 0.307 and 0.114, respectively). In Bland-Altman plot, the IOP values measured by Icare Pro(R) and TonoPen AVIA(R) exhibited excellent agreement with those measured by GAT. Both Icare Pro(R)/GAT and TonoPen AVIA(R)/GAT differences increased with younger age (p = 0.041 and 0.049, respectively) and higher central corneal thickness (p = 0.019 and 0.035, respectively). CONCLUSIONS: IOPs measured by portable Icare Pro(R) rebound tonometer and TonoPen AVIA(R) applanation tonometer were significantly correlated with IOP measured by GAT. Therefore, such instruments can be useful when measuring IOP with GAT is difficult. However, central corneal thickness and age should be considered when measuring IOP with portable tonometers.

Comparison of Intraocular Pressure Measured by Non-Contact Tonometer, Rebound Tonometer, Tono-Pen, and Goldmann Applanation Tonometer

PURPOSE: To compare the level of accuracy of intraocular pressure (IOP) measurements attained by non-contact tonometer (NCT), rebound tonometer (RT) Icare(R), and Tono-Pen (TONO-PEN AVIA(R)), using Goldmann Applanation tonometer (GAT) as a reference value and to explore their clinical usefulness. METHODS: In a prospective study of 71 normal eyes, IOP was measured with NCT, RT, Tono-Pen and GAT. The IOP values of were then compared between the eyes. RESULTS: RT showed statistically most significant agreement with the GAT [ICC 0.811, 95%CI 0.712-0.878]. In analysis of Bland-Altman plots, NCT showed the smallest mean bias (+0.2 mm Hg) and widest CI (95%CI; +/-5.05 mm Hg), RT showed relatively small mean bias (-0.7 mm Hg) and narrowest CI (95%CI; +/-3.75 mm Hg). CONCLUSIONS: There was a significant agreement between the RT and the GAT measurements. We expect RT to be considered as a reliable alternative when IOP measurement with GAT is not feasible.

Application of the domestic rebounder tonometer in children / 国际眼科杂志(Guoji Yanke Zazhi)

AlM:To evaluate the clinical application of the domestic rebound tonometer ( RBT ) in measuring intraocular pressure ( lOP) in healthy children. METHODS:lOP measurement was measured in bilateral eyes of 108 cases with domestic RBT. Then the lOP for the left eyes of the children older than 13 years was obtained with Goldmann applanation tonometry ( GAT) . RESULTS: Of the 108 children, 100 ( 92. 6%) had lOP measurement both eyes successfully. Of the 100 children, 24 were older than 13 years. The mean lOP values for the left eyes of the 24 children of RBT and GAT were (16. 0± 3. 0) mmHg (1kPa=7. 5mmHg) and (15. 7±2. 8) mmHg, respectively. There was no significant difference between the lOP of the two tonometers (P>0. 05). The lOP of RBT had a good liner relationship with that of GAT ( r=0. 849, P CONCLUSlON: Domestic RBT is a good instrument in detecting lOP in children and it seems to be very comfortable and easy when performing lOP measurement in children without an anesthetic.

Comparison of Icare Rebound Tonometer with Goldmann Applanation Tonometry

PURPOSE: To compare Icare rebound tonometer (IRT) and Goldmann applanation tonometer (GAT) and investigate the clinical usefulness of IRT. METHODS: In a retrospective study of 131 eyes with glaucoma and glaucoma suspect, intraocular pressure (IOP) was measured with IRT and GAT. The correlation between IRT and GAT and the influence of refractive error (spherical equivalent; SE) and central corneal thickness (CCT) were analyzed. RESULTS: A distinct correlation between IRT and GAT was found. IOP measured with GAT was 2.23 +/- 3.16 mm Hg higher than with IRT (p or = -5 diopter) was measured relatively lower than in hyperopic eyes (SE < -5 diopter) with GAT (+1.50 +/- 0.68 mm Hg) and IRT (+1.88 +/- 0.75 mm Hg). CONCLUSIONS: IRT showed strong correlation with GAT, but IOP measured approximately 2 mm Hg lower. The IOP tends to measure lower at low CCT and in myopic eyes.

Intraocular Pressure Measurement with the Noncontact Tonometer and Rebound Tonometer through Plano Soft Contact Lenses

PURPOSE: To investigate the accuracy of intraocular pressure (IOP) measurement through a plano soft contact lens (SCL) in situ by a noncontact tonometer (NCT) and a rebound tonometer (RBT). METHODS: The IOP of 66 eyes of 33 subjects with no ocular pathology was measured by NCT (tonometer CT-80, TOPCON, Japan) and RBT (iCare rebound tonometry(TM), Tiolat Oy, Finland). IOP measurement was repeated through plano SCL (ACUVUE OASYS(R), Johnson & Johnson Vision Care Inc., USA) in situ. Statistical analysis was performed using the paired t-test. RESULTS: Mean IOP measured by NCT was 13.10 +/- 2.52 mmHg without SCL and 12.95 +/- 2.56 mmHg with SCL. Mean IOP measured by RBT was 14.13 +/- 2.94 mmHg without SCL and 13.84 +/- 2.75 mmHg with SCL. No significant statistical differences were found between IOP measured with and without SCL (p=0.47, p=0.11 respectively). CONCLUSIONS: Reliable measurement of IOP by NCT and RBT can be achieved through plano SCL.

Comparison of Rebound Tonometer, Non-Contact Tonometer, Goldmann Applanation Tonometer and the Relationship to Central Corneal Thickness

PURPOSE: To compare the level of accuracy of intraocular pressure (IOP) measurements of a rebound tonometer (RT) Icare(R), and non-contact tonometer (NCT), using Goldmann Applanation tonometer (GAT) as a reference to evaluate the influence of central corneal thickness (CCT) on IOP readings in the Korean population. METHODS: In a prospective study of 273 eyes, IOP was measured with RT, GAT, and NCT and compared to CCT measurements. Patients were assigned to one of 3 groups based on IOP measurements of GAT and 1 of 2 groups based on CCT. The comparison of the IOP values of RT, GAT, and NCT was performed between the IOP and CCT groups, and the differences among tonometers were evaluated. RESULTS: The RT showed statistically significant correlation with the GAT compared to the NCT. The CCT was related to RT measurements. The RT values compared to the GAT was underestimated in thin corneas and overestimated in thick corneas. CONCLUSIONS: There was a significant correlation between the RT and the GAT measurements compared with the NCT. However, RT is influenced by CCT and correlates less with GAT in low IOP ranges, suggesting that corneal thickness should be taken into consideration during such measurements.

Comparison of intraocular pressure measured by Icare rebound tonometer and Goldmann applanation tonometer / 中华实验眼科杂志

Background As a new tonometer,it is necessary to assess the clinical value of Icare rebound tonometer.Objective This study was to compare the intraocular pressure(IOP)values measured by Icare with that measured by GAT,and discuss the clinical value of leare rebound tonometer. Methods IOP measurement was performed on 152 eyes of 78 subjects with suspicious glaucoma,glaucoma,refractive error and normal examinnee by Icare and GAT respectively.The Icare IOP was measured firstly and then the GAT IOP was carried out with the 3-or 5-minute interval.The IOP values were compared between Ieare and GAT.This study was approved by Ethic Committee of Wuhan General Hospital of Chinese PLA.Written informed consent was obtained from each subject prior to this study. Results The mean IOP values of Icare and GAT were(19.16±5.03)mmHg and(18.41±4.52)mmHg respectively.The differences between Icare IOP and CAT IOP were less than or equal to 1 mmHg in 96 of 105 eyes(63.2%).The positive correlation was found between the Icare IOP and GAT IOP(r=0.940,P<0.01).The Ieare IOP was lower than that of GAT when IOPIcare<16 mmHg,however,the IOP of Icare were higher when IOPIcare≥6 mmHg;the IOP of Icare were higher than that of GAT in the total CCT range.The correlation coefficients of IOP of Icare or CAT with CCT were 0.341(P<0.01)and 0.333(P<0.01),respectively. Conclusion Compared with GAT,Icare is more feasible in clinic because it is practicable and reliable.

Reproducibility and tolerability of iCare rebound tonometer and its agreement evaluation with Goldmann applanation tonometry / 中华实验眼科杂志

Background Goldmann applanation tonometry (GAT) is a gold standard of intraocular pressure measurement.But its utilization iS limited because of its complexity and high requirement of cooperation.iCare rebound tonometer (iCare RBT) is a new type of applanation tonometry,and its accuracy and safety in clinical application need to be evaluated.Objective Present study was to investigate the reproducibility and tolerability of iCare RBT and its measurement agreement with GAT over a wide intraocular pressure (IOP) range. Methods The IOP were measured in bilateral eyes of 36 glaucoma and glaucoma suspect patients by 2 examinees with iCare RBT at the 1-minute interval to assess the interobserver reproducibility.Then the IOP of both eyes from 56 Subjeets and other 52 subjects were separately measured twice for each by two operators with iCare RBT for the evaluation of intraobserver reproducibility.Finally.IOP of 182 eyes of 92 glaucoma and glaucoma suspect patients was obtained by examiner 2 with RBT first and examiner 1 with GAT subsequently at a 2.minute interval in a masked fashion to perform an agreement evaluation of two readings by using Bland-Ahman method.The tolerance of subjects to iCare RBT measurement were surveyed.Oral informed consent was obtained prior to the IOP measurement. Results Concerning the iCare RBT readings.interobserver correlation coefficients were 0.937 in the right eye and 0.887 in the left eye.Intraobserver correlation coefficients of examiner 1 were 0.986 in the left eyes and 0.969 in the fight eyes.And those of examiner 2 were 0.990 and 0.979.Mcan values of iCare RBT readings and GAT were(18.74±8.36)mmHg and(19.33±8.20)mmHg and the mean difference values(iCare-GAT)was(-0.59 4±2.60)mmHg with the 95%confidence interval of -5.80-4.60 mmHg.The correlation coefficient between two modalities of IOP measurement WaS 0.95 1.No severe pain and discomfort were complained in all the subjects during or after measurement of iCare RBT. Conclusion iCare RBT has good interobserver and intraobserver reproducibility and good tolerance.It was proved that this is a good correlation between iCare RBT readings and GAT readings.

Comparison of the Intraocular Pressure Measurement between Rebound Tonometer and Tonopen in Rats

PURPOSE: To compare the rebound tonometer with the TonoPen for measuring the intraocular pressure (IOP) in rats METHODS: Chronic IOP elevation models were induced unilaterally in nine Sprague-Dawley rats by applying an argon laser to the trabecular meshwork. IOP was measured before laser treatment and at one, two, and three days following laser treatment. Two independent operators collected five readings of the rebound tonometer and the TonoPen. Correlation analysis and comparison with the Bland & Altman method were performed. The intraclass correlation coefficient of each measurement and the difference between two independent operators were calculated. RESULTS: The IOP values measured with the rebound tonometer were well correlated with those of the TonoPen (r=0.676, p<0.001); however, the mean difference expressed as the percent difference of the averages of two tonometers, was 27.5%. The IOP values measured with a rebound tonometer exhibited a significantly higher intraclass correlation coefficient (0.966; 95% CI, 0.945-0.980 vs 0.412; 95% CI, 0.264-0.581) and a lower difference between the two operators (3.10+/-2.17 mmHg vs 6.17+/-5.17 mmHg) than those of the TonoPen. CONCLUSIONS: Although the IOP values measured with the rebound tonometer were lower than those of the TonoPen, they were in good agreement and were less variable than those of the TonoPen.