The validity of a digital eyelid tonometer (TGDc-01) and its comparison with Goldmann applanation tonometry – a pilot study

PURPOSE: To determine the intra- and inter-examiner repeatability of a new eyelid tonometer, and its agreement with Goldmann applanation tonometry (GAT). MATERIALS AND METHODS: Forty normal subjects were recruited and their intraocular pressure was measured by two examiners using the eyelid tonometer. Examiner 1 carried out the first set of measurement, followed by examiner 2, and then examiner 1 again. Finally, a third examiner was responsible for GAT measurement. Five readings were obtained from the eyelid tonometer by each examiner each time and were masked, and three readings were obtained from GAT. The mean readings from the eyelid tonometer and GAT were used for analysis. RESULTS: The intra-examiner repeatability for the eyelid tonometer was better (around +/-5 mmHg 95% of the cases) than the inter-examiner repeatability (around +/-8 mmHg 95% of the cases). The mean difference between the eyelid tonometer and GAT was small from examiner 1 (<0.5 mmHg). However, the limits of agreement were greater than the clinically acceptable level of +/-3 mmHg. Examiner 2 gave an even greater difference from GAT. CONCLUSIONS: Similar to other recent studies, we have found that this eyelid tonometer does not provide good agreement with GAT. Different examiners could position the instrument differently and this eyelid tonometer is suggested for screening purposes only.     

Comparison of the rebound tonometer with the Goldmann applanation tonometer in glaucoma patients

PURPOSE: To determine the agreement between the measurement of intraocular pressure (IOP) by the rebound tonometer (RBT) and by the Goldmann applanation tonometer (GAT) and to find out the effect of central corneal thickness (CCT) values on IOP measurements in glaucoma patients. METHODS: IOP was measured with the RBT and GAT, respectively, in 61 eyes of 61 glaucoma patients. CCT was measured using an ultrasonic pachymeter after all IOP determinations had been made. The mean IOP measurement by the RBT was compared with the measurement by the GAT, by Student's t-test. Bland-Altman analysis was performed to assess the clinical agreement between the two methods. The effect of CCT on measured IOP was explored by linear regression analysis. RESULTS: The mean patient age was 56.7+/-21.1 years (range: 30-80 years). There were 32 (52.46%) women and 29 (47.54%) men in the study group. The mean IOP readings were 18.70+/-4.76 mmHg using the RBT, and 18.27+/-3.49 mmHg using the GAT. The difference was not statistically significant (mean difference 0.43+/-2.55, P=0.2). A frequency distribution of the differences demonstrated that in more than 80% of cases the IOP readings differed by <2.3 mmHg between the RBT and GAT. There was a strong correlation between the RBT and GAT readings (r=0.852, P<0.0001). The IOP measurements with the two methods were correlated with CCT (r=0.40, P=0.02 for the RBT and r=0.48, P<0.0001 for the GAT). The IOP increased 1.1 mmHg and 8 mmHg for every 100-microm increase in CCT for the GAT and RBT, respectively. CONCLUSION: The RBT slightly overestimated the IOP value by 0.43 mmHg on average when compared with the GAT. Nevertheless, the RBT readings appeared to be more affected by the various thicknesses of different corneas when compared with those obtained using the GAT.     

Comparison of the new rebound tonometer with Goldmann applanation tonometer in a clinical setting

Purpose: To evaluate the clinical usefulness of a new rebound tonometer, Icare^® PRO (Icare PRO), by comparison with Goldmann applanation tonometry (GAT) in a study on patients with glaucoma. Methods: One hundred and seventy‐two eyes of 86 subjects were enrolled in this study. All of the subjects were examined with an autorefractometer, Icare PRO, slit‐lamp biomicroscope, GAT, ultrasound A‐scan and pachymeter. Three intraocular pressure (IOP) measurements were obtained by Icare PRO and GAT. The intraobserver reliabilities were established by calculating the intraclass correlation coefficients. The Bland–Altman plot was used to compare the Icare PRO and GAT. Results: There was a good correlation between the IOP measurement by GAT and that by Icare PRO (r = 0.6995, p < 0.001). The intraclass correlation coefficients of Icare PRO and GAT were 0.778 and 0.955, respectively. The IOP differences between Icare PRO and GAT (mean: 1.92 mmHg; SD: 3.29 mmHg; 95% limit of agreement: ?4.52 to 8.37 mmHg) did not vary over the wide range of central corneal thickness (p = 0.498), age (p = 0.248), axial length (p = 0.277) or spherical equivalent (p = 0.075). Conclusions: Although IOP with Icare PRO was higher than that with GAT, especially at lower GAT IOP value, Icare PRO was found to be a reliable method and showed a good correlation with GAT. The IOP difference between Icare PRO and GAT was not affected by the central corneal thickness, age, axial length or spherical equivalent. Icare PRO can be expected not only to be a good screening tool but also to be a good substitute for GAT.     

Comparison of iCare tonometer and Goldmann applanation tonometry in normal corneas and in eyes with automated lamellar and penetrating keratoplasty

Purpose

To compare intraocular pressure (IOP) measurements with Goldmann applanation tonometry (GAT) and iCare tonometry in normal and post-keratoplasty corneas and to assess the influence of central corneal thickness (CCT), corneal curvature (CC), and corneal astigmatism (CA) on IOP.

Methods

This prospective cross-sectional study included one eye of 101 subjects with normal corneas (58 healthy subjects, 43 glaucoma); and 90 post-keratoplasty patients: 34 penetrating keratoplasties (PK); 20 automated-lamellar-therapeutic keratoplasties (ALTK); 19 Descemet-stripping-automated-endothelial keratoplasties (DSAEK); 17 edematous grafts. All subjects underwent GAT and iCare IOP measurements in random order, and CCT, CC, and CA evaluation. The Bland–Altman method and multivariate regression analysis were used to assess inter-tonometer agreement and the influence of CCT, CC, and CA on IOP.

Results

iCare significantly underestimated IOP in all groups compared with GAT (GAT minus iCare of 3.5±3.5 mm Hg, P<0.001), but overestimated IOP in the edematous grafts (GAT minus iCare of −6.5±1.9 mm Hg, P<0.001). In normal corneas, both tonometer measurements were directly related to CCT values; iCare readings appeared inversely related to CC. There was no significant relationship between IOP and CCT, CC and CA in post-keratoplasty eyes, except between CC and iCare measurements for PK eyes.

Conclusions

The agreement between GAT and iCare was clinically acceptable in control, ALTK and DSAEK groups, and poor in PK and edematous grafts eyes. In normal corneas, GAT was significantly affected by CCT; iCare was influenced by CCT and CC. The iCare appeared less influenced by corneal edema when compared with GAT. High IOP readings taken with both tonometers in grafts should raise suspicion of true elevated IOP.     

Comparison of intraocular pressure measurement between rebound, non-contact and Goldmann applanation tonometry in treated glaucoma patients

Background: To compare the intraocular pressure readings obtained with the iCare rebound tonometer and the 7CR non‐contact tonometer with those measured by Goldmann applanation tonometry in treated glaucoma patients. Design: A prospective, cross‐sectional study was conducted in a private tertiary glaucoma clinic. Participants or Samples: One hundred nine (54 males : 55 females) patients including only eyes under medical treatment for glaucoma. Methods: Measurement by Goldmann applanation tonometry, iCare rebound tonometry and 7CR non‐contact tonometry. Main Outcome Measures: Intraocular pressure. Results: There were strong correlations between the intraocular pressure measurements obtained with Goldmann and both the rebound and non‐contact tonometers (Spearman r‐values ≥ 0.79, P < 0.001). However, there were small, statistically significant differences between the average readings for each tonometer. For the rebound tonometer, the mean intraocular pressure was slightly higher compared with the Goldmann applanation tonometer in the right eyes (P = 0.02), and similar in the left eyes (P = 0.93); however, these differences did not reach statistical significance. The Goldmann correlated measurements from the non‐contact tonometer were lower than the average Goldmann reading for both right (P < 0.001) and left (P > 0.01) eyes. The corneal compensated measurements from the non‐contact tonometer were significantly higher compared with the other tonometers (P ≤ 0.001). Conclusions: The iCare rebound tonometer and the 7CR non‐contact tonometer measure intraocular pressure in fundamentally different ways to the Goldmann applanation tonometer. The resulting intraocular pressure values vary between the instruments and will need to be considered when comparing clinical versus home acquired measurements.     

Performance of the rebound,noncontact and Goldmann applanation tonometers in routine clinical practice

Purpose: To compare rebound tonometry (RBT) and noncontact tonometry (NCT) using Goldmann applanation tonometry (GAT) as reference. Methods: The study sample was comprised of 108 eyes of 108 subjects consecutively examined at a general ophthalmology clinic. The order of use of the three tonometers was randomized at the study outset. The difference between the methods was plotted against the mean to compare the tonometers. The hypothesis of zero bias was examined by a paired t‐test and 95% limits of agreement (LoA) were also calculated. Differences with respect to GAT were assessed according to the international standard for ocular tonometers (ISO 8612). Results: Mean intraocular pressures (IOPs ± SD) obtained using the three instruments were GAT 17.5 ± 3.8 mmHg; RBT 18.5 ± 5.5 mmHg and NCT 17.4 ± 5.6 mmHg. The 95% LoA were from ?7.9 to +7.7 mmHg for NCT–GAT and from ?6.8 mmHg to +8.7 mmHg for RBT–GAT. A difference with respect to GAT under ±1 mmHg was observed in 11.1% of the eyes measured by NCT and 18.5% of eyes measured by RBT. According to the IOP ranges established by the ISO 8612, differences from GAT measurements greater than ±5 mmHg were always above the accepted level of 5%. Correlations between IOP and central corneal thickness (CCT) were significant for all three tonometers. Conclusions: The rebound and noncontact tonometer behaved similarly when used to measure IOP taking GAT measurements as the reference standard. Neither tonometer fulfilled ISO 8612 requirements. Both were similarly influenced by CCT.     

Comparison of Goldmann applanation tonometry, rebound tonometry and dynamic contour tonometry in normal and glaucomatous eyes

AIM: To compare the intraocular pressure (IOP) measurements obtained with the rebound tonometry (RT), dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) in normal and glaucomatous eyes and investigate the effects of central corneal thickness (CCT) and corneal curvature (CC) on IOP measurements. METHODS: One hundred and twenty-four eyes of 124 subjects were enrolled in this cross-sectional study. Fifty-six of participants were healthy individuals and 68 of them were glaucomatous patients. IOP was measured on each subject always in the same order, ICare RT-Pascal DCT-GAT, after a minimum interval of 10min between measurements. CCT and CC were measured using a rotating Scheimpflug camera before the IOP measurements in all subjects. One way repeated measures ANOVA, Pearson correlation coefficient and regression analysis, and Bland-Altman analysis was used for the statistical assessment. RESULTS: Mean IOP for all enrolled eyes was 16.00±3.80 mm Hg for GAT, 16.99±4.91 mm Hg for RT, and 20.40±4.44 mm Hg for DCT. Mean differences between GAT and RT was -1.75±3.41 mm Hg in normal (P<0.001) and -0.37±3.00 mm Hg in glaucomatous eyes (P=0.563). Mean differences between GAT and DCT was -4.06±3.42 mm Hg in normal (P<0.001) and -4.67±3.12 mm Hg in glaucomatous eyes (P<0.001). GAT and RT were significantly positive correlated with CCT in normal (r=0.317, P=0.017 and r=0.576, P<0.001, respectively) and glaucomatous eyes (r=0.290, P=0.016 and r=0.351, P=0.003, respectively). DCT was also significantly positive correlated with CCT in normal eyes (r=0.424, P=0.001) but not in glaucomatous eyes (r=0.170, P=0.165). All tonometers were unaffected by CC. CONCLUSION: IOP measurements by RT and DCT were significantly higher than GAT. DCT has highest IOP measurements among these tonometers. RT was most influenced tonometer from CCT although all tonometers were significantly positive correlated with CCT except DCT in glaucomatous eyes. CC did not influence IOP measurements.     

The relationship between central corneal thickness and Goldmann applanation tonometry

Background: The aim of this study was to investigate the relationship between Goldmann applanation tonometry and central corneal thickness in a large sample of healthy eyes. Method: Five hundred eyes of 500 subjects (253 women, 50.6 per cent and 247 men, 49.4 per cent) were analysed in a prospective healthy population study. Mean age of the sample was 31 ± 8 years. Goldmann applanation tonometry was carried out by one physician. Tonometric values were the mean of three consecutive readings. Subsequently, another physician carried out ultrasonic pachymetry with the DGH 2000 AP ultrasonic pachymeter (DGH Technology Inc, San Diego, USA). Ten measurements were made at the centre of the cornea of each eye. The lowest value was used for analysis. Results: Applanation tonometry and central corneal thickness were correlated (r = 0.184, p < 0.001). There was no significam correlation between corneal thickness and age (r = 0.083, p = 0.065), mean spherical equivalem refraction (r = 0.083, p = 0.065) or visual acuity (r = 0.036, p = 0.187). Conclusion: In normal eyes, there is no statistically significant correlation between changes of intraocular pressure and changes of central corneal thickness but they suggest a relationship between intraocular pressure and central corneal thickness. Goldmann applanation tonometry has a systematic error in accuracy of intraocular pressure readings of healthy eyes caused by its dependence on central corneal thickness. Measurement of corneal thickness by optometrists should be the first step in diagnosing intraocular pressure pathologies.     

非接触式和Goldmann压平眼压计测量结果的一致性分析

目的：在原发性开角型青光眼（ POAG ）中应用佳能TX-F非接触式眼压计（ NCT）和Goldmann压平眼压计（ GAT）测量眼压（ IOP）,并比较测量值。 方法：55例（55右眼）确诊为POAG的患者接受详细的眼科检查,光学相干断层扫描成像和自动视野检查。使用NCT1（一次喷气模式）, NCT3（三次喷气模式）和GAT测量眼压,每隔5分钟一次。 结果：55例（55右眼） POAG 患者平均年龄为64.1±8.1岁。比较NTC1,NTC3测量的眼压值（14.22±3.42,14.28±3.29mmHg）与GAT测量的眼压值（14.66±3.49mmHg）无统计学差异（ P=0.291）。使用Bland-Altman 方法比较NCT1-GAT, NCT3-GAT和NCT1-NCT3得出的95%一致性界限（IOA）分别为-4.9~＋4.4mmHg,-4.1~＋3.4mmHg和-3.4~＋3.3 mmHg。 结论：虽然NCT与GAT测量的眼压值相似,但偏大的IOA范围限制了NCT1,NCT3和GAT在POAG患者中的互换应用。     

iCare回弹式眼压计与Goldmann压平眼压计测量结果的比较

目的对比iCare回弹式眼压计（RBT）与Goldmann压平眼压计（GAT）测量眼压的一致性,评价RBT测量眼压的准确性及安全性。方法研究为诊断性试验评价。分别用2种眼压计测量角膜正常的患者52例104眼,其中男28例,女24例;年龄19～76岁,以GAT眼压值作为基准分为5组：≤10mmHg、11～20mmHg、21～30mmHg、31～40mmHg、≥41mmHg组。评估2种测量方法的眼压值差值及其与眼压的关系。对RBT眼压值随GAT眼压值变化的关系进行评价。结果 RBT测得的眼压读数为（17.20±9.13）mmHg,GAT测得的眼压读数为（17.13±8.94）mmHg,二者差异无统计学意义（t=0.260,P=0.795）。60.58%的患者2种方法测得的眼压差值在1mmHg以内。5个组中,GAT眼压与RBT眼压的绝对差值随着眼压读数的增高而加大,最大值在≥41mmHg组,二者的最大绝对差值〈4mmHg。RBT眼压读数随着GAT眼压读数的改变而变化,二者的变化呈现良好的相关性（r=0.917,P〈0.01）,但与GAT测量法比较,RBT测得的眼压值均稍高。当GAT眼压值〉21mmHg时,RBT测量的敏感度和特异度分别为95.5%和98.8%。RBT测量后25%的患者主诉有异物感和眼干。结论 iCareRBT测量眼压具有良好的耐受性和安全性,与GAT测量眼压具有较好的相关性,适用于临床。     

iCare回弹式眼压计测量的重复性及与Goldmann压平式眼压计测量值间的一致性研究

背景Goldmann压平式眼压计（GAT）是眼压测量的金标准,但由于操作复杂且需要良好配合而影响其临床应用。iCare回弹式眼压计（RBT）是一种新型的压平式眼压计,但需进行充分的临床应用评价。目的对iCareRBT检查者间及检查者内测量的可重复性及iCareRBT与GAT测量值间的一致性进行研究。方法2位操作者使用iCareRBT对36例青光眼及可疑青光眼患者双眼各测量1次,分别记录读数,对iCareRBT检查者间的重复性进行评价。2位操作者使用iCareRBT分别测量56例青光眼和52例青光眼患者,并对可疑青光眼患者的双眼进行测量,并记录眼压读数,对iCareRBT检查者内的重复性进行评价。检查者2对青光眼及可疑青光眼患者92例182眼先使用iCareRBT进行测量,然后检查者1使用Goldmann压平式眼压计进行测量,对iCareRBT和GAT的测量值进行一致性检验,并评价iCareRBT测量眼压的安全性。结果iCareRBT检查者间眼压测量值相关因子r右眼为0．937,左眼为0．887;检查者1对右眼和左眼重复测量眼压值的r值分别为0．986、0．969,检查者2所测右眼和左眼的r值分别为0．990、0．979;iCareRBT测量值与CAT测量值的均值分别为（18．74±8．36）mmHg、（19．33±8．20）mmHg,二者差值为（-0．59±2．60）mmHg,95％CI为（-5．80～4．60）,2种测量法相关因子r为0．951。所有受试者对iCareRBT的测量无不适反应。结论iCareRBT具有检查者间和检查者内的高度可重复性及很好的耐受性,iCareRBT测量值与GAT测量值间具有高度相关性。     

The iCare rebound tonometer: comparisons with Goldmann tonometry, and influence of central corneal thickness

Purpose:  To assess agreement between the iCare rebound tonometer and Goldmann tonometry and to assess the influence of central corneal thickness and the value of scleral rebound tonometer readings.
Methods:  Prospective single-centre cross-sectional study comparing iCare rebound tonometer (RT) intraocular pressure (IOP) readings taken from corneal and scleral locations to Goldmann applanation tonometer (GAT) readings in 100 subjects attending ophthalmology clinics.
Results:  There was a significant difference between RT and GAT, with RT tending to overestimate IOP. The mean difference between RT and GAT measurements was 3.36 mmHg. The mean difference between the log of RT and the log of GAT measurements was 0.2356, a ratio of 1.27 ( P  < 0.0001). A formula derived from a linear regression analysis suggested that a 10% increase in CCT increased the RT IOP reading by 9.9%. Scleral RT readings showed no relationship to GAT readings.
Conclusions:  The rebound tonometer cannot replace the Goldmann tonometer in the office setting given the wide limits of agreement between the two devices. Corneal rebound tonometer readings are influenced by CCT whereas scleral rebound tonometer readings are of no value.     

中央角膜厚度对3种眼压计眼压测量值的影响

目的比较分析不同中央角膜厚度(central corneal thickness,CCT)下Icare回弹式眼压计、Goldmann压平式眼压计(Goldmann applanation tonometer,GAT)和动态轮廓眼压计(dynamic contour tonometry,DCT)的眼压测量结果,探讨CCT对3种眼压计测量值的影响。方法 对78例患者152眼分别用Icare、GAT、DCT3种眼压计进行眼压测量,并进行CCT的测量,对比不同CCT下3种眼压计的测量结果,分析眼压测量值与CCT的关系。结果 在全部受测者中Icare、GAT、DCT测得的眼压均值分别为(19.16±5.03)mmHg(1 kPa=7.5 mmHg)、(18.41±4.52)mmHg和(17.23±3.69)mmHg,三者之间有显著差异(F=7.256,P=0.001)。Icare和GAT的眼压测量值均与CCT显著相关(r=0.341,P<0.001;r=0.333,P<0.001),CCT每改变10μm,Icare的眼压值改变0.47 mmHg,GAT的眼压值改变0.41 mmHg;而DCT的眼压测量值与CCT无显著相关(r=0.032,P=0.699)。结论 Icare、GAT的眼压测量值均明显受CCT的影响,而Icare受CCT影响的程度较GAT的稍大,DCT的眼压测量值基本不受CCT的影响。     

Should Orbscan pachometry be performed before or after Goldmann applanation tonometry?

PURPOSE: To compare the Orbscan central corneal thickness (CCT) values before and after intraocular pressure (IOP) measurement with Goldmann applanation tonometry in young normal adults. MATERIALS AND METHODS: Fifty-three eyes of 53 subjects who were free from any ocular problems were studied. The measurements included optical pachometry by the Orbscan II system, followed by Goldmann applanation tonometry, and finally Orbscan optical pachometry again. Standard Goldmann technique was adopted with the application of one drop of 0.4% benoxinate and fluorescein sodium prior to the measurement. The same operator was involved in the Orbscan pachometry before and after Goldmann tonometry. Another investigator was responsible for Goldmann tonometry. Three readings were obtained in each case, and the means were used for analysis. RESULTS: The mean IOP of the sample was 14.6 +/- 2.6 mmHg. There was no significant difference (paired t-test: p = 0.50) in the mean CCT values before and after the Goldmann tonometry (551 +/- 32 and 552 +/- 35 microm respectively). CONCLUSION: Standard Goldmann applanation tonometry does not affect the Orbscan CCT values. Measurement of CCT for the adjustment of true IOP can be carried out either before or after Goldmann tonometry.     

Goldmann tonometry versus the Tono-Pen XL for intraocular pressure measurement: an evaluation of the potential impact on clinical decision making in glaucoma

Aim:  To assess the validity of the Tono-Pen XL as an alternative to the Goldmann applanation tonometer (GAT) for the measurement of intraocular pressure (IOP) in patients with ocular hypertension (OHT) and glaucoma.
Methods:  Over a 3 month period, patients with OHT or glaucoma attending a general clinic had IOP measurements taken using the Tono-Pen XL and the GAT. Tono-Pen measurements were taken by suitably trained nursing staff, while Goldmann tonometry was performed by the examining ophthalmologist.
Results:  There were 124 eyes of 62 patients in this study. Overall, mean IOP was 18.3 ± 4.8 mmHg using GAT and 18.8 ± 5.5 mmHg using the Tono-Pen. Using the Bland–Altman method, the upper and lower limits of agreement between the two devices were +10.6mmHg and −9.6 mmHg, respectively. Significant over- and under-estimates of IOP were noted in 10 (16%) patients.
Conclusion:  Our findings suggest that the Tono-Pen XL cannot be used as a substitute for GAT in the management of patients with glaucoma or OHT.     

Comparison of dynamic contour tonometry with Goldmann applanation tonometry in glaucoma practice

Purpose: To compare intraocular pressure (IOP) readings taken using dynamic contour tonometry (DCT) with IOP readings taken with Goldmann applanation tonometry (GAT) in eyes with glaucoma or ocular hypertension. Methods: The present study included 100 eyes in 100 patients with glaucoma or ocular hypertension. After pachymetry DCT and GAT were performed. Intraocular pressures as measured with DCT and GAT were compared with one another and with central corneal thickness (CCT). Results: Mean DCT IOP measurements (20.1 ± 4.3 mmHg) were significantly (p < 0.001) higher than GAT IOP values (17.9 ± 4.7 mmHg). The mean difference between DCT and GAT measurements was 2.1 mmHg (range ? 3.4 to 9.7 mmHg). The difference followed a normal distribution. Measurements made with DCT and GAT correlated significantly with one another (Spearman’s rho = 0.761, p < 0.001). Neither GAT nor DCT measurements showed a significant correlation with CCT (537 ± 39 μm, range 458–656 μm). Multivariate regression analysis has shown that the difference between DCT and GAT is influenced significantly by ocular pulse amplitude (r = ? 0.334, p = 0.001) and it is not influenced by CCT (r = ? 0.106, p = 0.292). Conclusions: In eyes with glaucoma or ocular hypertension, DCT facilitates suitable and reliable IOP measurements which are in good concordance with GAT readings. Variation in CCT cannot by itself explain the differences in measurements taken with DCT and GAT in a number of 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。     

Pascal,ICare and Goldmann applanation tonometry – a comparative study

Purpose: To compare intraocular pressure (IOP) measurements by Pascal, ICare and Goldmann applanation tonometry (GAT), to evaluate the effects of central corneal thickness (CCT) and curvature on IOP measurement and to estimate the intra‐observer variability. Methods: A prospective, single‐centre study of 150 eyes with a wide range of pressures. Six masked IOP measurements/method; corneal thickness and curvature were studied for each eye. GAT was the reference. Results: IOP_Pascal and IOP_ICare correlated with IOP_GAT (r = 0.91, 0.89). Mean ICare measurement exceeded GAT by 2 mmHg. Pascal measured higher than GAT at low IOPs and lower at high IOPs. For every 10 mmHg increase in IOP above 31 mmHg, Pascal measured 2 mmHg lower than GAT and vice versa. CCT was correlated significantly with IOP_GAT (r = 0.23) and IOP_ICare (r = 0.43) but not with IOP_Pascal (P = 0.12). CCT was correlated with age. In a subgroup (>50 years), ICare and the difference between IOP_GAT and IOP_Pascal were affected significantly by the CCT, whereas IOP_GAT and IOP_Pascal were not. Corneal curvature was correlated significantly with IOP_GAT (r = ?0.27) and IOP_Pascal (r = ?0.26) but not with IOP_ICare (P = 0.60). Intra‐observer variability within each set of six measurements was approximately 2 mmHg, irrespective of method. Conclusion: This study showed a reasonable overall correlation and concordance between the IOP obtained with the three instruments. None of the methods were completely independent of the biomechanical properties of the cornea. ICare showed a significant dependency upon CCT, whereas GAT and Pascal showed a significant dependency on corneal curvature. All methods showed intra‐observer variability, which leaves room for further improvement of methods.     

Comparison of rebound and applanation tonometry in the management of patients treated for glaucoma or ocular hypertension.

AIM: To compare intraocular pressure (IOP) values obtained with the iCare rebound tonometer (RBT) with values obtained with the Goldmann applanation tonometer (GAT) in patients with glaucoma and ocular hypertension, and to evaluate the impact of possible differences on management decisions. METHODS: The IOP was measured with the iCare RBT and GAT in 45 consecutive patients in a nurse-led glaucoma unit. The outcome measures were the IOP difference between the methods and the 95% limits of agreement (LoA) for IOP measurements. In all subjects where the IOP readings differed by >3 mmHg between the RBT and GAT, two ophthalmologists were independently asked to recommend treatment and/or follow-up intervals, based on the patients' clinical data and the IOP values. RESULTS: The RBT overestimated the IOP compared with GAT in 67% of the cases (30/45). In 78% (35/45) the IOP difference was within +/-3 mmHg. When an extreme value of 15 mmHg difference was excluded, the 95% LoA was +/-4.31 mmHg. In five of the 10 patients with an IOP difference of > +/- 3 mmHg the difference would have led to change in therapy; in three more patients the follow-up interval would have been changed. In the remaining two patients the difference in IOP would not have led to any change in management. CONCLUSIONS: The mean difference between RBT and GAT was small (1.5 +/- 3 mmHg) compared with the published repeatability of GAT values. Yet, the difference was found to have clinical implications in 18% (8/45) of the patients.     

动态轮廓眼压计监测LASIK手术前后眼压变化

目的比较动态轮廓眼压计(DCT)、Goldmann压平式眼压计(GAT)及非接触式眼压计(NCT)测量接受准分子激光原位角膜磨镶术(LASIK)患者眼压值的差异。设计前瞻性临床试验研究。研究对象接受LASIK治疗的近视患者70例(140眼)。方法对上述患者于术前、术后1周,1、6个月用三种不同眼压计分别测量眼压,比较各时间点、各种眼压计之间的差异。同时记录手术前、后中央角膜厚度,取其两者差为角膜切削深度的值。主要指标眼压值(IOP)和角膜切削深度。结果术后1周,1、6个月DCT测量值(16.74±1.96mmHg、16.67±1.90mmHg、16.42±2.12mmHg)与其术前值(17.36±2.32mmHg)比较差异无统计学意义(F=1.346,P=0.06)。术后GAT和NCT测量值均呈下降趋势,与术前测量值比较差异有统计学意义(GAT:F=101.217,P=0.000;NCT:F=171.466,P=0.000),并且下降值与角膜切削深度成正相关关系(GAT:r=0.86,P=0.000;NCT:r=0.87,P=0.000),但术后三个时间段测量值比较差异无统计学意义(GAT术后三个时间点q值为0.216、0.677、0.461,P值分别为0.461、0.097、0.117;NCT术后三个时间点q值为0.215、0.585、0.370,P值分别为0.436、0.436、0.100)。结论LASIK术后GAT和NCT测量值明显下降,而DCT测量值无显著变化,其测量值较前两者更为可靠。(眼科,2007,16:344-347)