Agreement and repeatability of Icare ic100 tonometer

Purpose:To find the agreement and repeatability of Icare ic100 tonometer.Methods:We included 150 subjects above the age of 18 years for this cross-sectional, multicenter study with intraocular pressure (IOP) ≥7 mmHg. After the initial ophthalmic examination, two masked examiners took five IOP measurements using three different instruments; Icare ic100, Icare TA01i, and Goldmann applanation tonometer (GAT) in only one eye of the participants. Comparison of agreement of IOP using different instruments was quantified with intraclass correlation coefficient (ICC) using the two-way random effects models of absolute agreement and Cronbach''s alpha. The test-retest variability of the instruments was assessed by deriving repeatability coefficient (RC) and coefficient of variation (CV).Results:Agreement between the tonometers across the different IOP groups had no statistically significant difference in their mean IOP. Icare ic100 was found to have good reliability across all IOP groups (ICC value >0.78) when compared with Icare TA01i. In comparison with GAT, Icare ic100 showed good reliability across all IOP groups (ICC >0.87) except >16 to <23 mmHg group where it showed moderate reliability (ICC = 0.52). Icare ic100 showed good repeatability with RC and CV of 2.67 and 4.89, respectively.Conclusion:Icare ic100 rebound tonometer can measure IOP with relatively small measurement error and can provide a reliable and repeatable reading in comparison with GAT across a wide pressure range without hampering corneal health.     

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。     

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.     

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.     

Clinical comparison of the Icare tonometer and Goldmann applanation tonometry

PURPOSE: To compare a new method of intraocular pressure (IOP) measurement, using the Icare tonometer, with Goldmann applanation tonometry (GAT). PATIENTS AND METHODS: Two observers obtained IOP readings in 292 eyes (143 right and 149 left) of 153 subjects, using the Icare without topical anesthetic. A GAT reading was subsequently obtained by a consultant ophthalmologist, without the knowledge of the Icare readings. Central corneal thickness (CCT) was obtained on all eyes with ultrasound pachymetry. Patient comfort after IOP measurement was assessed in a consecutive subset of patients. RESULTS: The intraclass correlation coefficient between the 2 modalities of IOP measurement was r=0.95 for the right and r=0.93 for the left eye. The mean difference (Icare-GAT) between the IOP measured by the 2 methods was 0.4 mm Hg in the right eye (SD 3.0, 95% confidence interval -5.5 to 6.3), and 0.8 mm Hg in the left eye (SD 3.0, confidence interval -4.7 to 6.2). GAT measurements did not vary with CCT [correlation coefficient=0.09 (P=0.25) right and 0.14 (P=0.09) left eyes]. However, IOP measured with Icare tonometry increased with increasing CCT [correlation coefficient=0.16 (P=0.05) right and 0.21 (P=0.01) left eyes]. For every 100-microm increase in CCT, the difference (Icare-GAT) increased by 1 mm Hg. Of the 38 consecutive patients surveyed, 28 (73.7%) rated the Icare more comfortable than GAT, with only 2 (5.3%) rating it less comfortable (P<0.001). CONCLUSIONS: There is good correlation between the 2 methods of IOP measurement, even at extremes of IOP. The Icare instrument was easy to use and recorded rapid and consistent readings with minimal training. It seems to be more comfortable than GAT and obviates the need for topical anesthesia.     

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。     

三种不同眼压计眼压测量值的比较

目的:比较分析Icare回弹式眼压计、GAT和DCT的眼压测量结果,探讨Icare回弹式眼压计的临床性能。方法:78例152眼分别用Icare,GAT,DCT3种眼压计进行眼压测量,然后根据测得的眼压高低分为高眼压、中眼压、低眼压3个组,对比分析3种眼压计的测量结果。结果:在全部受测者中Icare,GAT,DCT测得的眼压均值分别为19.16±5.03mmHg,18.41±4.52mmHg和17.23±3.69mmHg,每两种眼压计相比均有显著差别,但是彼此之间密切相关。高、中、低3个眼压组两种眼压计之间的差值均随着眼压的增高而增大。结论:使用Icare测量的眼压值准确可信,Icare,GAT和DCT的眼压值彼此之间具有良好的相关性。     

Evaluation of some factors affecting the agreement between the Proview Eye Pressure Monitor and the Goldmann applanation tonometer measurements

Background: Our aim was to examine whether training level and ocular factors could account for part of the difference in intraocular pressure (IOP) measured using the Goldmann applanation tonometer (GAT) and Proview Eye Pressure Monitor (PPT). Methods: One hundred and nineteen individuals (238 eyes) were enrolled in the study. The mean age was 35.8 years (range 21 to 79). All study participants obtained IOP measurements using the PPT after hearing instructions on how to perform PPT. Glaucoma patients obtained additional IOP measurements using PPT after viewing an instructional video and after 30 days of home use. IOP was also measured using the GAT at each experimental session. Results: The difference in IOP measured by the GAT and the PPT was 0.55 ± 3.38 mmHg, 0.17 ± 3.79 mmHg and ‐1.30 ± 3.79 mmHg for myopic, emmetropic and hypermetropic groups, respectively, which were statistically significant (ANCOVA; p = 0.014). The difference in IOP between GAT and PPT was not significantly different for measurements obtained after verbal instructions, instructional video or after 30 days of home use (Repeated‐ANCOVA; p = 0.30). The overall agreement between the GAT and the PPT was poor. Intra‐class correlation coefficient was 0.575, and the 95% confidence interval (CI) of agreement was ‐6.93 to +6.73 mmHg. Conclusion: There was a small systematic difference in IOP measured by the GAT and PPT when comparing the different refraction groups; however, this level of difference between the groups is unlikely to be of clinical significance. The level of training in using the PPT did not influence its measurements. The limits of agreement between the PPT and the GAT were wide and long‐term use of PPT did not improve its agreement.     

Goldmann压平眼压计与非接触式眼压计测量眼压的对比研究

目的:比较Goldmann压平眼压计(Goldmannapplanationtonometer,GAT)与非接触眼压计(non-contacttonometer,NCT)测量眼压的差异,以评价NCT与GAT测量的相关性。方法:对265例志愿者(529眼)分别采用Goldmann压平眼压计与非接触眼压计测量眼压。结果:非接触眼压计的测量结果低于Goldmann压平眼压计,且差异有显著性(19.13vs23.43,t=22.644,P<0.01),随眼压值的升高,两者相差幅度增大,差异在眼压〉30mmHg时更为明显,但相关系数逐渐变小。结论:非接触眼压计眼压测量值较Goldmann眼压测量值偏低,非接触眼压计眼压值为临界眼压时,需应用Gold-mann压平眼压计校正,以便及时发现病理性眼压升高,避免青光眼的漏诊和失治。     

五种眼压计测量眼压的一致性比较及其与角膜生物力学的相关性

目的 比较非接触眼压计（气流眼压）、Goldmann压平眼压计（压平眼压）、Icare pro回弹眼压计（回弹眼压）、Tono-pen AVIA眼压计（笔式眼压）和可视化角膜生物力学分析仪（生物力学眼压）测量眼压的一致性,进一步分析眼压和角膜生物力学的相关性。设计 诊断方法评价。研究对象 健康志愿者44例。方法 同一医师每天同一时段分别应用上述五种眼压计测量受试者的左眼眼压。将眼压与中央角膜厚度、角膜第一压平时间进行Pearson相关分析。主要指标 眼压值、眼压差值的平均值、相关系数。结果 压平眼压、气流眼压、回弹眼压、笔式眼压和生物力学眼压5种眼压结果分别为（15.9±3.3）mmHg、（14.8±2.9）mmHg、（16.9±3.3）mmHg、（14.7±2.5）mmHg和（16.1±3.0）mmHg。其中,气流眼压、笔式眼压较压平眼压低（P=0.01,0.00）。气流眼压、回弹眼压、笔式眼压、生物力学眼压均与压平眼压正相关（r=0.63、0.37、0.63、0.55,P均＜0.05）;Bland-Altman分析两种测量方式眼压差值平均值分别为：气流眼压与压平眼压：-1.1 mmHg [95%一致性界限（95% LoA）为-6.4,4.2],笔式眼压与压平眼压：-1.2 mmHg（95% LoA -6.3,3.9）,回弹眼压与压平眼压：1.0 mmHg（95% LoA为-6.2,8.3）,生物力学眼压与压平眼压：0.3 mmHg（95% LoA为-5.6,6.2）。所有研究对象中央角膜厚度（550.5±29.2）μm,角膜第一压平时间（7.63±0.36）ms。笔式眼压和中央角膜厚度呈正相关（r=0.40,P=0.01）。五种测试的眼压均与角膜第一压平时间呈正相关（r=0.53,0.64,0.55,0.46,0.99;P均＜0.05）。结论 Icare pro和Corvis ST测量眼压与Goldmann眼压计无明显差异,气流眼压、笔式眼压较压平眼压略低,Corvis ST与Goldmann眼压一致性最好。角膜第一压平时间是影响眼压测量结果的重要因素,时间越长,眼压测量值越高。（眼科, 2020, 29： 365-369）     

iCare回弹式眼压计的临床应用评价

目的比较iCare回弹式眼压计（RBT）测量的眼压值与Goldmann压平眼压计（GAT）测量眼压值的差异,评价RBT测量眼压的可靠性及可重复性。方法对正常志愿者9例9眼同时使用iCareRBT和GAT进行测量,比较二者眼压测量结果的重复性。对GAT眼压在正常范围内的受试者（包括可疑青光眼患者和眼压控制良好的青光眼患者）45例45眼分别用RBT和GAT进行测量,使用配对t检验、相关分析及Bland-Altman图一致性检验等方法比较二者测量结果的一致性。由2位操作者使用同一台RBT对13位正常志愿者13眼进行测量,通过组内相关系数比较各自测量结果的重复性,从而评价不同操作者对iCareRBT测量结果的影响,模拟真实临床工作环境。结果 RBT组眼压读数的组内相关系数为0.821（95%CI：0.553～0.952）,GAT组眼压读数的组内相关系数为0.846（95%CI：0.604～0.959）,表明2种仪器的测量重复性均较好,但尚不能说明何种更好。RBT和GAT测得的眼压分别为（14.42±3.49）mmHg和（16.18±2.68）mmHg,二者呈正相关（r=0.684,P〈0.01）;但RBT所测的眼压读数略低于GAT,差异有统计学意义（t=4.601,P〈0.01）。Bland-Altman图显示二者的差值为（-1.76±2.56）mmHg,95%CI：（-6.77～3.26）。使用RBT所测眼压值的组内相关系数分别为0.827（95%CI：0.626～0.938）和0.697（95%CI：0.413～0.884）。结论 RBT与GAT所测得的眼压值在正常范围内,具有较好的相关性,2种眼压计测量的重复性均较好,而不同操作者测量的重复性不完全一致。     

PASCAL动态轮廓眼压计临床应用的初步报告

目的:验证动态轮廓眼压计(DCT)的临床性能。方法:对81例143眼青光眼及可疑病例青光眼患者用DCT测量眼内压(IOP);132眼同时用Goldmann压平眼压计(GAT)测量眼压,部分病例同时用NIDEKUP-1000型角膜测厚仪测量中央角膜厚度(CCT)。GAT与DCT测量结果采用配对t检验,GAT、DCT测量值与CCT的关系及DCT测量值与眼脉动振幅(OPA)的相关关系采用Spearman双变量相关分析。结果:①DCT和GAT测得的眼压均数分别为(18.6±3.9)mmHg和(17.4±4.1)mmHg;DCT测得的眼压值高于GAT,其差值均数为(1.1±2.3)mmHg;两种眼压计测得的眼压值呈正相关(r=0.83,P<0.01)。②116眼同时完成了DCT眼压测量及CCT测量,两者相关系数r=0.03,P=0.77;113眼同时完成了GAT眼压测量及CCT测量,两者相关系数r=0.28,P=0.003。③143眼同时记录了DCT眼压值和眼脉动振幅(OPA),其均数分别为(18.6±3.9)mmHg和(2.6±1.1)mmHg,两者的相关系数r=0.32,P<0.01。结论:以上结果初步证实:①DCT眼压计测量值与GAT眼压测量值高度相关,但DCT测量值略高于GAT测量值,提示DCT可用于临床诊断。②DCT测量值与CCT不相关,GAT测量值与CCT显著相关,提示DCT在青光眼诊断中有独特优势。③DCT测量的OPA与IOP值显著相关,相关的机制及临床意义有待探讨。     

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。     

Goldmann眼压计与非接触眼压计测量青光眼患者眼压的对比分析

目的：：对比分析 Goldmann 压平式眼压计( Goldmann applanation tonometer, GAT)和非接触眼压计( non-contact tonometer,NCT)测量青光眼患者眼压的结果,寻找其规律性。方法：分别使用GAT和NCT测量108例206眼青光眼患者的眼压。结果：青光眼患者108例206眼的平均眼压：GAT测量为29.77±10.27mmHg,NCT测量为24.59±8.58mmHg,两者比较存在显著性差异(P<0.01),而且眼压越高,差异性越显著。结论：NCT 测量值较 GAT 测量值低,眼压越高,差值越大。建议使用GAT检查青光眼患者的眼压,以免漏诊和贻误治疗。     

非接触式眼压计与Goldmann压平眼压计测量眼压值一致性的Meta分析

背景 非接触式眼压计(NCT)是临床常见的眼压测量设备,其测量值受角膜参数等多种因素的影响,近年有临床研究针对NCT与“金标准”Goldmann眼压计(GAT)测量眼压值一致性的报道,但尚缺乏循证评价. 目的 从循证医学的角度评价NCT与GAT测量眼压值的一致性. 方法 采用严密制定的检索策略检索MEDLINE、EMbase、中国生物医学文献数据库、中国期刊全文数据库文献,检索年限为从各数据库建库至2016年6月.按照纳入和排除标准筛选文献,提取样本量、平均年龄、样本特征、随访时间、NCT与GAT眼压测量等数据.使用Cochrane协作网提供的Review Manager 5.3.0软件进行合并效应量的检测,6篇文献间经I2检验存在异质性,采用随机效应模型校正后对NCT与GAT测量的眼压值进行分析. 结果 初步检索共获得24篇文献,筛选后共纳入NCT与GAT测量眼压值的比较研究6篇,总样本量为478眼.采用随机效应模型校正后,NCT的眼压测量值较GAT眼压测量值高0.02 mmHg(1 mmHg=0.133 kPa),差异无统计学意义[加权均数差(WMD)=0.02,95％可信区间(CI):-0.59 ～ 0.63,P=0.95].漏斗图法显示文献存在发表偏倚.结论 NCT与GAT测量正常人群眼压结果具有较好的一致性,但尚需更多大样本比较研究提供支持.     

Intraocular pressure measurement over soft contact lens by rebound tonometer:a comparative study

AIM: To evaluate the intraocular pressure (IOP) measurements by Icare rebound tonometer over a contact lens in comparison with Goldmann applanation tonometry (GAT).METHODS: Fifty patients using contact lens were included in this study. One of the eyes of the patients was selected randomly and their IOP were measured by rebound tonometer with and without contact lens (RTCL, RT respectively) and by GAT, as well as their central corneal thickness (CCT) by optical pachymeter. The results of both methods were compared by correlation analysis, general linear method repeated measure and Bland-Altman analysis.RESULTS: Mean IOP values measured by RTCL, RT and GAT were 15.68±3.7, 14.50±3.4 and 14.16±2.8 (P<0.001), respectively. Mean IOP by RTCL was significantly higher than the measurements implemented by RT and GAT (P<0.001), while there was no difference between the measurements by GAT and RT (P=0.629). There was a good level of positive correlation between GAT and RTCL as well as RT (r=0.786 P<0.001, r=0.833 P<0.001, respectively). We have observed that CCT increase did not show any correlation with the differences of the measurements between RTCL and RT (P=0.329), RTCL and GAT (P=0.07) as well as RT and GAT (P=0.189) in linear regression model.CONCLUSION: The average of the measurements over contact lens by rebound tonometer was found to be higher than what was measured by GAT. Although this difference is statistically significant, it may be clinically negligible in the normal population.     

Effects of central corneal thickness and corneal curvature on the intraocular pressure measurement by Goldmann applanation tonometer and ocular blood flow pneumatonometer

PURPOSE: To assess the effects of central corneal thickness (CCT) and corneal curvature (CC) on the measurements of intraocular pressure (IOP) using Goldmann applanation tonometer (GAT) and the ocular blood flow pneumatonometer (OBFT). METHODS: 104 patients were recruited from a glaucoma clinic. The CCT was measured using ultrasound pachymetry and the mean radius of CC using a keratometer. The IOP of each eye was measured using both GAT and the OBFT in a random order. Right eyes only were analysed for statistical purposes. RESULTS: The mean (+/-SD) IOP by GAT and OBFT was 18.2 mmHg (+/-4.4) and 18.2 mmHg (+/-4.0), respectively, with no statistically significant difference. IOP measurement with both instruments varied with CCT and CC. GAT showed an IOP increase of 0.40 mmHg per 10 microm increase of CCT and OBFT showed an increase of 0.38 mmHg in IOP per 10 microm increase of CCT. Multiple regression analysis showed that the effect of CCT was statistically significant (P<0.001) on IOP recorded by both the GAT and OBFT but CC did not have a statistically significant effect on IOP recordings performed by either technique. CONCLUSION: IOP measurements by GAT and OBFT are positively correlated with CCT with both tonometers being similarly affected. There was no significant correlation between CC and IOP measured by either tonometer.     

国产回弹式眼压计在儿童眼压测量中的应用

目的：观察国产回弹式眼压计在儿童眼压监测中的应用。方法：对本院眼视光门诊就诊的108例儿童进行两眼眼压测量,年龄大于13岁的儿童回弹式眼压计（ rebound tonometer,RBT）测量完成后左眼进行Goldmann压平式眼压计（ Goldmann applanation tonometry,GAT）眼压测量。 结果：两眼均顺利完成RBT眼压测量的儿童100例,成功率92.6%（100/108）,其中13岁以上24例。24例左眼RBT和GAT眼压平均值分别为16.0±3.0 mmHg （1 kPa=7.5mmHg）和15.7±2.8mmHg,两者差异无统计学意义（P〉0.05）,两者具有良好的相关性（r=0.849,P〈0.05）。100例儿童的左右眼眼压均呈正态分布,平均值分别为16.0±2.8mmHg和16.2±2.6mmHg,两者差异无统计学意义（P〉0.05）,两者具有良好的相关性（r=0.863,P〈0.05）。 结论：国产回弹式眼压计在儿童眼压测量中简单易操作,无需麻醉,准确性较高,能够较好满足临床儿童眼压测量的需求。     

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.     

Effect of central corneal thickness on intraocular pressure and comparison of Topcon CT‐80 non‐contact tonometry with Goldmann applanation tonometry

Background

To compare intraocular pressure (IOP) measurements obtained with the Topcon CT‐80 non‐contact tonometer (NCT) and Goldmann applanation tonometer (GAT), in different ranges of IOP in normal and glaucoma subjects, and to assess the influence of central corneal thickness (CCT) on the IOP measurements in Asian Indian eyes.

Methods

Four hundred and two eyes of 402 subjects (193 newly diagnosed primary open angle glaucoma [POAG] and 209 normal) were enrolled for this prospective study. For each eye, IOP was measured with GAT by a glaucoma specialist and NCT by a trained optometrist. The IOP values were compared among the tonometers in the three different IOP ranges (≤ 12 mmHg, 13–20 mmHg and ≥ 21 mmHg) using Bland–Altman graphs. Correlation between GAT and NCT was assessed by Pearson correlation co‐efficient. CCT was measured with ultrasound pachymetry and its correlation with GAT and NCT was analysed using linear regression analysis.

Results

The mean paired difference of IOP between NCT and GAT was 1.556 ± 2.69 mmHg (r = 0.26, p = 0.006) at IOP range of ≤ 12 mmHg, ?1.665 ± 2.6 mmHg (r = 0.51, p < 0.0001) in IOP range of 13–20 mmHg and ?2.202 ± 3.44 mmHg (r = 0.82, p < 0.0001) in the IOP range of ≥ 21 mmHg. Linear regression analysis showed a mean IOP variation of 0.27 mmHg per 10 μm change in CCT for NCT (p < 0.0001) and IOP change of 0.19 mmHg per 10 μm change in CCT for GAT (p = 0.01).

Conclusion

In this study of normotensive and POAG subjects, the Topcon CT‐80 NCT showed an overestimation of IOP at the lower range and underestimation of IOP in normal and higher ranges of IOP. Clinicians should keep in mind that CCT influences IOP measurement with both types of tonometer and that the IOP readings obtained with these tonometers are not interchangeable.