ICare回弹式眼压计与NCT测量结果的比较

目的：比较ICare回弹式眼压计（ICareRBT）和非接触眼压计（NCT）测量值的一致性,评价ICareRBT的测量精确性。方法：对113例222眼（右眼111眼,左眼111眼）随机使用NCT和ICare回弹式眼压计测量眼压,对两种眼压计所测眼压值的差异采用配对t检验分析法,对ICare所测眼压值随NCT所测值变化的关系分析采用线性回归分析法,对ICare与NCT眼压测量值的一致性采用Bland-Altman分析法。结果：使用ICareRBT和NCT测得的眼压均值分别为18.46±8.50mmHg和17.09±8.32mmHg,二者差值为1.36±1.52mmHg,两种测量方法Pearson相关因子r为0.984。Bland-Altman分析证实ICareRBT与NCT眼压测量值具有良好的一致性。所有受试者对ICareRBT的测量无不适反应。结论：ICareRBT与NCT测量值间具有高度的相关性,可以作为可靠的筛查工具,并可以在临床广泛应用。     

ICARE回弹式眼压计与NCT眼压计测量结果的比较

目的:讨论ICARE回弹式眼压计的临床性能。方法:对78例156眼同时用ICARE回弹式眼压计和NCT眼压计进行眼压测量,对比分析两种眼压计的测量结果及两者的相关情况;观察ICARE眼压计对特殊病例测量的结果。结果:ICARE眼压计和NCT眼压计测得的眼压均值分别为16.55±8.54mmHg和16.81±7.35mmHg,两者无显著差别。两种眼压计测量值显著相关,相关系数为0.964。ICARE眼压计可较好地完成角膜病变和无固视能力等病例的眼压测量。结论:ICARE眼压计可以在临床上运用,尤其适用于其它眼压计测量困难的病例。     

非接触式眼压计与回弹式眼压计在眼压测量中的准确度分析

目的：分析非接触式眼压计(non contact tonometer,NCT)、ICare回弹式眼压计(ICare rebound tonometer,RBT)在青光眼患者中眼压测量结果的准确性。

方法：回顾性病例对照研究。选取青光眼患者113例185眼。用RBT、NCT和Goldmann眼压计(GAT)分别于9：00、16：00两次进行眼压测量并记录为两组数据,分别用秩和检验、国际标准8621指南评估其准确性,Bland-Altman一致性分析两组测量结果的一致性,并以GAT测量值作为标准将数据分为异常眼压组(<10mmHg或>21mmHg)和正常眼压组(10～21mmHg),在不同组间分析其一致性。应用Spearman相关分析眼压计间的相关性。

结果：GAT、NCT和RBT三组测量值间存在差异(P<0.01); GAT获得的眼压测量值与RBT和NCT测量值间存在相关性(r_s=0.71、0.77,P<0.001)。NCT与GAT测量值接近(P=0.92),而RBT与GAT相比,眼压测量值较高(P<0.05)。然而NCT、RBT同GAT相比一致性界限范围均较宽,分别为-6.2～6.0、-5.2～7.6mmHg,在正常眼压组一致性界限范围分别为-5.9～5.9、-4.3～7.5mmHg,在非正常眼压组分别为-7.3～6.4、-7.5～5.6mmHg。根据ISO 8612指南进行评价,NCT和RBT在三组中超过95%的一致性限制的异常值分别为3.9%、11.3%、12.2%和26.3%、11.3%、12.2%。

结论：NCT和RBT均不能简单代替GAT用于青光眼患者眼压的测量。在青光眼患者中,随着测量值偏离正常眼压范围,NCT和RBT的测量误差也有所增大。     

Assessing intraocular pressure by rebound tonometer in rats with an air-filled anterior chamber

Purpose  To compare rebound tonometer and cannulation as methods for measuring intraocular pressure (IOP) in rats. Methods  The accuracy of the TonoLab rebound tonometer was determined in eight cannulated rat eyes. IOP was manipulated by changing air pressure from 20 to 100 mmHg at 10-mmHg intervals, and the IOP was measured with the rebound tonometer at each level. The average value of three repeated pressure readings was recorded. Correlation analysis and comparison with the Bland and Altman method were performed. The intraclass correlation coefficient was calculated to assess intraoperator variability. Results  The IOP values measured with the TonoLab rebound tonometer were well correlated with the actual IOP (r ² = 0.963, P = 0.01). The mean of the difference between the rebound tonometer and actual (cannulation) IOP was 7.41 ± 7.87%. The intraclass correlation coefficient was 0.9, indicating low intraoperator variability. Conclusions  The rebound tonometer showed high accuracy and reliability for IOP measurement in rat eyes.     

Icare回弹式眼压计与Goldmann压平眼压计眼压测量结果的比较

背景Icare回弹式眼压计作为一种新式眼压计,有必要对它的临床应用价值进行评估。目的通过比较分析Icare回弹式眼压计和Goldmann压平眼压计（GAT）的眼压测量结果,探讨Icare的临床价值。方法可疑青光眼、青光眼、屈光不正及部分健康体检者78例共152眼同时接受Icare、GAT眼压测量,受检眼先行Icare测量,然后再进行GAT测量,2次测量间隔3～5min。对比分析两种眼压计的测量结果。结果使用Icare和GAT测得的眼压均值分别为（19．16±5．03）mmHg和（18．41±4．52）mmHg,96眼（63．2％）两者的眼压差值≤1mmHg,二者的测量值差异虽有统计学意义,但二者的变化呈明显正相关（r=0．940,P〈0．01）。当Icare眼压测量值〈16mmHg时,Icare的眼压测量值低于GAT,而当Icare眼压测量值≥16mmHg时恰好相反;CCT偏薄、正常以及偏厚的情况下,Icare的眼压测量值均高于GAT的眼压测量值。Icare、GAT的眼压测量值和CCT间呈正相关（r=0．341,P〈0．01;r=0．333,P〈0．01）。结论与GAT眼压计比较,Icare回弹式眼压计易操作,测量结果可靠,临床实用性更强。     

Noninvasive measurement of rodent intraocular pressure with a rebound tonometer

PURPOSE: The present study evaluated the applicability of a rebound tonometer in measuring intraocular pressure (IOP) in rats and mice. METHODS: The accuracy of the TonoLab rebound tonometer was determined in cannulated mouse and rat eyes. IOP was manipulated by changing reservoir height, and tonometer pressure readings were recorded by an independent observer. IOP values were recorded in conscious Wistar rats and in four different strains of mice. The effects of anesthesia on IOP were evaluated in two different strains of mice. RESULTS: The IOP readings generated by the rebound tonometer correlated very well with the actual pressure in the eye. In rats, this linear correlation had a slope of 0.96 +/- 0.05 (mean +/- SEM, n = 4) and a Y-intercept of -2.1 +/- 1.2. In mice, the slope was 0.99 +/- 0.05 (n = 3), and the Y-intercept was 0.8 +/- 1.4. Using this method, the resting IOP of conscious male Wistar rats was observed to be 18.4 +/- 0.1 mm Hg (n = 132). In mice, strain differences in IOP were detected. Baseline IOP values in Balb/c, C57-BL/6, CBA, and 11- to 12-month-old DBA/2J mice were 10.6 +/- 0.6, 13.3 +/- 0.3, 16.4 +/- 0.3, and 19.3 +/- 0.4 mm Hg (n = 12), respectively. In separated studies, anesthesia lowered IOP from 14.3 +/- 0.9 to 9.2 +/- 0.5 mm Hg (n = 8) in C57-BL/6 mice, and from 16.6 +/- 0.4 to 9.4 +/- 0.6 mm Hg (n = 10) in CBA mice. CONCLUSIONS: The rebound tonometer was easy to use and accurately measured IOP in rats and mice. This technique, together with advances in genetic and other biological studies in rodents, will be valuable in the further understanding of the etiology and pathology of glaucoma.     

A new rebound tonometer for home monitoring of intraocular pressure

Background  

To compare intraocular pressure (IOP) measurements obtained by the Icare ONE rebound tonometer (RTONE) and the Goldmann applanation tonometer (GAT) in healthy persons and glaucoma patients in a prospective study, and to investigate the influence of central corneal thickness (CCT).     

Age differences in central and peripheral intraocular pressure using a rebound tonometer

AIM: To evaluate the influence of age on the measurements and relationships among central and peripheral intraocular pressure (IOP) readings taken with a rebound tonometer. METHODS: The IOPs were measured using the ICare rebound tonometer on the right eyes of 217 patients (88 men and 129 women) aged 18-85 years (mean 45.9 (SD 19.8) years), at the centre and at 2 mm from the nasal and temporal limbus along the horizontal meridian. Three age groups were established: young (< or =30 years old; n = 75), middle aged (31-60 years old; n = 77) and old patients (>60 years old; n = 65). RESULTS: A high correlation was found between the central and peripheral IOP readings, with the central readings being higher than the peripheral ones. Higher IOP values for the central location were found in the younger patients. Older patients had significantly lower temporal IOP readings than those for the remaining two groups (p<0.001), whereas no significant differences were found among groups when IOP was measured at the central and nasal locations. A significant decrease was observed in the nasal and temporal IOP readings as the age increased (p = 0.011 and 0.006, respectively). CONCLUSION: Older patients had lower IOP values than the middle-aged and younger patients in the temporal peripheral location. A negative correlation was found between age and IOP by rebound tonometry in the corneal periphery but not in its centre.     

Assessment of IcareONE rebound tonometer for self‐measuring intraocular pressure

Purpose: To evaluate the precision of the IcareONE rebound tonometer, which was developed for self‐measuring intraocular pressure (IOP) and to compare IcareONE measurement with Goldmann applanation tonometry (GAT). Methods: Twenty‐four healthy eyes and 81 glaucomatous eyes were enrolled. IOP measurements (three times per session) with IcareONE were made in a random order by an ophthalmologist (Icare(O)) and by the subject (Icare(S)). Intraclass correlation coefficients (CCs), kappa values and mean values of IOP were compared among the two types of Icare recordings and GAT. Bland–Altman analysis was used to assess agreement between methods. Multiple regression analysis was performed to identify the subject factors that influenced the discordant measurements between IcareONE and GAT. Results: The mean value of Icare(O) and Icare(S) measurements was 13.5 ± 5.2 and 13.5 ± 5.4 mmHg, respectively, neither of which was significantly different from GAT (13.8 ± 4.4). The intrarater CC of Icare(O) and Icare(S) was 0.968 and 0.885, respectively. The intermethod CC and weighted kappa between Icare(O) and Icare(S) were 0.907 and 0.684, respectively. All pairwise correlations between the two types of IOP measurement showed coefficients of determination >0.8. Bland–Altman analysis did not show any proportional biases. Multiple regression analysis revealed that the differences between GAT and Icare(O) or Icare(S) were positively correlated with central corneal thickness (CCT) and negatively correlated with age. Conclusions: Intraocular pressure measurements with IcareONE by a physician and by the subject showed excellent agreement with GAT measurements; IcareONE measurements between a physician and the subject had high intrarater reliability, and good agreement thicker CCT led IcareONE measurement to overestimate IOP, while higher age caused it to underestimate IOP compared with GAT.     

Evaluation of the Icare-ONE rebound tonometer as a self-measuring intraocular pressure device in normal subjects

Purpose

To compare Icare ONE rebound self-tonometer (ICRBT) measurements with Goldman applanation tonometry (GAT).

Methods

A trained examiner instructed each of 60 normal subjects on use of the ICRBT. Each subject then took two measurements of his/her own pressure using the ICRBT. Finally, a different examiner, who was masked to the earlier readings, measured IOP by GAT. Bland–Altman limits of agreement (LOA), intraclass correlation coefficients (ICCs), Kappa values, and paired t-test were used to assess the agreement between the two methods. Pearson’s correlation coefficient was used for correlation analysis.

Results

All of the subjects were able to obtain correct measurements with ICRBT after three attempts. The mean intraocular pressure with ICRBT and GAT measurements were 16.0?±?3.3?mmHg and 13.7?±?2.5?mmHg respectively. The mean difference between patient’s ICRBT and technician’s GAT measurements was 2.3?mmHg (p?p?r?=?0.48, p?r?=?0.31, p?=?0.015), indicating that greater thickness is associated with greater differences between the two methods.

Conclusion

The ICRBT was reliable in the hands of normal subjects, and may be used for self-monitoring of IOP. ICRBT measurements generally overestimated GAT measurements.     

Effectiveness of the ICare rebound tonometer in patients with overestimated intraocular pressure due to tight orbit syndrome

Purpose

To evaluate the effectiveness of the ICare rebound tonometer in patients with overestimated intraocular pressure (IOP) due to tight orbit syndrome and to identify factors affecting the development of tight orbit syndrome in glaucoma patients.

Methods

We investigated 84 eyes in 84 glaucoma patients, of which 14 eyes were classified in the tight orbit syndrome group and 70 eyes in the control group. IOP was measured using the ICare tonometer and the Goldmann applanation tonometer (GAT). The demographic data, medical histories, ocular histories, and detailed ocular drug histories of the two groups were compared to identify factors contributing to the development of tight orbit syndrome.

Results

In the tight orbit syndrome group, the ICare tonometer significantly underestimated the IOP by approximately 8.6 mmHg compared with the GAT. In the control group, the IOP readings of the GAT and the ICare tonometer did not differ significantly. Bland–Altman analysis showed that the mean difference between measurements taken using the GAT and those taken using the ICare tonometer was 2.5 ± 6.3 mmHg. The difference between the GAT and ICare tonometer measurements was greater in the tight orbit syndrome group (8.6 ± 5.3 mmHg) than in the control group (1.3 ± 2.7 mmHg). Multivariate regression analysis revealed that only the use of prostaglandin analogs (PGAs) was associated with the development of tight orbit syndrome.

Conclusions

The ICare tonometer is a suitable alternative device for use in patients with tight orbit syndrome in whom the IOP may be overestimated with the GAT. The prolonged use of PGAs is significantly associated with the development of tight orbit syndrome.     

Agreement of rebound tonometer in measuring intraocular pressure with three types of applanation tonometers

PURPOSE: To evaluate the agreement of iCare rebound tonometer in measuring intraocular pressure (IOP) with Goldmann applanation tonometer (GAT), Tonopen XL, and noncontact tonometer, and the influence of the central corneal thickness (CCT) on IOP measurements made with these four tonometers in 45 (12 control and 33 glaucomatous or ocular hypertensive) eyes. DESIGN: Clinically relevant experimental study. METHODS: Tonometer intermethod agreement was assessed by the Bland-Altman method. The relations of CCT with absolute IOP values and intertonometer differences were analyzed by linear regression. RESULTS: The mean differences (95% limits of agreement) in IOP readings between iCare and GAT, Tonopen XL, and noncontact tonometer were 1.40 +/- 4.29, 0.00 +/- 4.78, and 2.22 +/- 4.19 mm Hg, respectively. All tonometries had a marked association with CCT. As the CCT got thicker, iCare considerably overestimated GAT and Tonopen XL. CONCLUSIONS: Although influenced by CCT, iCare agrees well with applanation tonometers.     

Tono-pen眼压计与Goldmann眼压计对穿透性小梁切除术后患者眼压测量的比较

目的:寻找穿透性小梁切除术后患者眼压测量的简单方法。方法:随机选取行穿透性小梁切除术后3d的患者120例120眼。分别用Goldmann眼压计和Tono-pen眼压计测量眼压,比较两种眼压测量值的差异。结果:120眼中,Goldmann眼压计所测量眼压的平均数值14.69±4.60mmHg。Tono-pen所测眼压的平均数值14.72±4.62mmHg。经统计学检验,P>0.05,Tono-pen眼压计与Goldman眼压计的测量结果无显著性差异。对于穿透性小梁切除术后的眼压测量,Tonopen眼压计与Goldman眼压计的测量结果有高度相关性。Tono-pen眼压计可以准确地估计眼压值。结论:对于穿透性小梁切除术后的的患者眼压在7～32mmHg间时Tono-pen眼压计可以作为一种准确测量眼压的简单方法。     

The induction/impact tonometer: a new instrument to measure intraocular pressure in the rat

Non-invasive intraocular pressure (IOP) measurement in rats can be performed with a variety of methods, none of which seems appropriate for scaling down for the mouse eye. In an attempt to develop such a method for non-invasive IOP measurement in mice, an alternative concept, that of rebound tonometry, was explored using an induction/impact (I/I) tonometer probe. IOP measurement using the rebound concept is based on bouncing a probe onto the eye and detecting its motion. Motion parameters of the probe, which vary according to eye pressure, are used to calculate the IOP.As a first step towards this goal a prototype I/I tonometer was evaluated for IOP measurement of the rat eye. Two similar instruments were constructed and tested for their ability to measure accurately and reliably rat IOP by comparing the measurements against the manometric (true) IOP as determined by cannulation ex vivo. Good correlation between the true IOP and the I/I measurements (R(2) = 0.95) was detected for IOP between 7.4 and 56 mmHg. Although individual eyes tested showed some variability in the relationship of the measured IOP with the true IOP, this variability was minimal.Starting probe-cornea distance between 3 and 5 mm, and angle of impact up to 25 degrees relative to the visual axis at the corneal apex, did not affect the reproducibility of the I/I tonometer. Comparison of I/I tonometer measurements to direct manometric determination of IOP by in vivo cannulation of eyes in anesthetized normal female Wistar rats correlated reasonably well (R(2) = 0.67) with manometrically determined IOP within the narrow range of normal rat IOPs (10-16.5 mmHg), underestimating the true (manometric) IOP by an average of 11.6%.The I/I tonometer is a reliable and accurate instrument for non-invasive IOP measurement in rat eyes that can potentially be adapted for IOP measurement in mice.     

Non-invasive determination of intraocular pressure in the rat eye. Comparison of an electronic tonometer (TonoPen), and a rebound (impact probe) tonometer

BACKGROUND: The reproducibility and accuracy of the induction/impact (I/I) probe device (rebound tonometer) and the TonoPen XL electronic tonometer were compared through the measurement of intraocular pressure (IOP) differences between contralateral rat eyes. METHODS: IOP was measured in 18 female Wistar rats with variable, modest elevations of IOP in one eye. Mean IOP from five measurements on each of the 36 eyes was determined using the rebound tonometer, followed by the TonoPen XL. Following cannulation, true (manometrically determined) IOP was recorded with a calibrated pressure transducer. Differences between the operated and normal eye of each animal for each tonometric method of measurement were correlated with the true difference in IOP. RESULTS: IOP differences between the operated and contralateral normal eye ranged from +5.9 to -1.7 mmHg (mean +1.7 mmHg) when measured by cannulation and from +7.2 to -1.4 mmHg (mean +2.4 mmHg) and +9.8 to -3.2 mmHg (mean +3.6 mmHg) when measured with the rebound tonometer and TonoPen XL respectively. Differences between eyes recorded by rebound tonometer ( y) correlated with those determined by cannulation ( x) in a linear fashion ( y=0.8243 x+1.0721; R(2)=0.6603). Correlation for the TonoPen XL was much weaker ( y=0.8675 x+2.1672; R(2)=0.2077). IOP measurements using the rebound tonometer did not differ significantly from true IOP, whereas TonoPen XL increasingly underestimated IOP with increasing IOP (9-20 mmHg). CONCLUSION: The rebound tonometer displayed greater accuracy and less variability than TonoPen XL in measuring the IOP of the rat eye (range 9-20 mmHg).