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。     

三种眼压计对维族和汉族大学生眼压测量值比较

目的：比较Goldmann眼压计、非接触式眼压计与Schiotz眼压计对维吾尔族、汉族大学生眼压测量值结果。

方法：横断面研究。分别采用Goldmann眼压计、非接触式眼压计与Schiotz眼压计测量维吾尔族、汉族大学生眼压。比较两族整体间、同族不同性别间、不同眼别间三种眼压计测得的眼压值。

结果：相同眼压计对维吾尔族及汉族大学生眼压测量值差异有统计学意义(P<0.05); 相同眼压计对同族不同性别间眼压测量值差异无统计学意义(P>0.05); 相同眼压计对不同眼别间眼压测量值差异无统计学意义(P>0.05),汉族学生比维吾尔族学生眼压测量值高(P<0.05),非接触式眼压计比Goldmann眼压计眼压测量值偏高(P<0.05),非接触式眼压计比Schiotz眼压计眼压测量值要小(P<0.05)。

结论：同一眼压测量仪对同族不同性别间及不同眼别间无差异,汉族学生比维吾尔族学生眼压测量值高,Schiotz眼压计眼压值测量结果显著高于非接触式眼压计,而非接触式眼压计眼压测量值高于Goldmann眼压计。     

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。     

角膜厚度对两种眼压测量方法的影响

目的　比较非接触眼压计 (non -contacttonometer ,NCT)和Goldmann压平眼压计测量眼压的差异 ,并分别探讨中央角膜厚度 (centralcornealthickniss ,CCT)对这两种测量方法的影响。方法　对 1 0 8例拟接受PRK或LASIK手术的患者行CCT ,NCT和Goldmann压平计眼压测量。结果NCT和Goldmann压平眼压计测得的眼压均值具有显著性差异 (F =89 .70 4 4,P <0 . 0 1 )。CCT与NCT和Goldmann压平眼压计测量值呈正相关 ,相关系数分别是r =0. 4 96 0 (t =8 .356 3,P <0 .0 0 1 )和r =0 . 2 1 1 3(t =3. 1 6 2 3,P <0 .0 0 1 )。结论　NCT和Goldmann压平眼压计测量眼压值有差异 ,NCT测量值大于Goldmann压平眼压计 ,CCT对NCT的影响大于Goldmann压平眼压计。     

使用不同眼压计比较翼状胬肉术后绷带镜对眼压的影响

目的：利用回弹式眼压计(RT)及非接触式眼压计(NCT)测量并比较翼状胬肉术后配戴治疗用绷带镜时与裸眼眼压的差异。

方法：选取2019-04/06在开封市中心医院开封眼病医院手术治疗的翼状胬肉患者(鼻侧原发性翼状胬肉小于4mm且术后配戴治疗用绷带镜)50例50眼。于术后14d用RT及NCT分别在戴镜状态、裸眼状态测量患者眼压,比较并分析翼状胬肉术后治疗用绷带镜对眼压测量的影响。

结果：RT在戴镜状态、裸眼状态测得的眼压分别为18.20±3.19、15.17±3.80mmHg,相差3.04±1.79mmHg,且前后两次测量具有良好的相关性(r=0.884,P<0.001); NCT在戴镜状态、裸眼状态测得的眼压分别为15.74±3.23、13.19±3.89mmHg,相差2.55±1.88mmHg,且具有良好的相关性(r=0.876,P<0.001); 在戴镜状态及裸眼状态,两种设备测量所得眼压分别相差2.46±1.45、1.98±1.67mmHg,RT测量结果均显著高于NCT测量结果(P<0.001)。

结论：翼状胬肉术后应用RT、NCT测量配戴治疗用绷带镜状态与裸眼状态的眼压一致性均较好,但在配戴治疗用绷带镜时两种眼压计均有高估患者眼压风险,且应用RT在戴镜状态及裸眼状态眼压高估较NCT更明显。     

眼反应分析仪与非接触眼压计眼压测量的对比观察

目的比较眼反应分析仪(ORA)与非接触眼压计(NCT)测量眼压结果的差异,分析ORA、NCT测量结果与角膜中央厚度(CCT)的关系。方法近视患者57例(114只眼),于准分子激光手术前行ORA测量,得出角膜补偿眼压(IOPcc)和Goldmann相关眼压值(IOPg)两个数值,NCT测眼压3次取平均值。结果 ORA测得IOPcc平均值16.85 mm Hg,IOPpg平均值15.26 mm Hg,NCT眼压计测得平均值15.66 mm Hg;IOPcc>NCT>IOPg。IOPcc、IOPg与NCT所测眼压值比较,差异均有统计学意义(P<0.05)。NCT和IOPg均与CCT呈正相关(r:分别为0.463和0.419,P<0.05);IOPcc与CCT无相关性(r:0.230,P>0.05)。结论 ORA测量屈光不正患者的眼压与NCT测量结果存在一定差异,其中IOPcc不受角膜厚度的影响,在临床运用中准确性较好。     

三种眼压计与Pentacam眼压校正系统的应用比较

目的:比较非接触式眼压计(NCT)、Goldmann压平式眼压计(GAT)、动态轮廓眼压计(DCT)和Pentacam三维眼前节分析系统四种方法检查眼压的差异,并研究它们与中央角膜厚度(CCT)和中央角膜曲率(CCV)的关系。方法:对拟行LASIK手术的143例286眼患者用Pentacam系统测量CCT和CCV后,分别用NCT,GAT和DCT测量眼压,并用Pentacam系统的Ehlers,Shah,Dresden,Orssengo/Pye和Kohlhaas5种眼压校正方法对NCT眼压值进行校正,将测量结果进行方差分析、相关性及线性回归分析。结果:DCT值最高,DCT与其他方法之间均有显著性差异(P<0.01);GAT与DCT,Kohlhaas,Shah之间有差异(P<0.05),与其他方法之间无差异;各组眼压值之间有较好的相关性,GAT与DCT的相关性最强(r=0.702);NCT受CCT影响最大,GAT受CCV影响最大,DCT,Dresden,Orssengo/Pye,Shah与CCT和CCV均不存在相关性(P>0.05)。结论:对CCT和CCV正常的健康人群进行青光眼筛查时建议使用压平式眼压计,对可疑的患者,尤其是CCT和CCV偏离正常的患者,宜进一步行DCT检查或者用Pentacam系统进行眼压校正。     

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。     

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的比较

目的 :比较非接触式眼压计 ( NCT)和 Goldm ann压平眼压计测量眼压的差异。方法 :对 112例 ( 2 2 0眼 )志愿者分别进行 NCT和 Goldmann压平眼压计眼压测量及中央角膜厚度测量 ,并对其中 16 8眼进行自动验光检查。结果 :NCT和 Goldmann眼压计眼压测量值分别为 1.98± 0 .6 9k Pa和 2 .34± 0 .77k Pa。 NCT眼压测量值较 Goldmann眼压测量值偏低 0 .36± 0 .37k Pa( P<0 .0 5 )。眼压在 1.33～ 2 .6 7k Pa内 ,二种眼压计测量眼压值偏差最小。角膜厚度和眼球屈光度与 NCT眼压测量值分别呈明显正相关和负相关。结论 :NCT眼压测量值较Goldmann眼压测量值偏低 ,NCT眼压值为临界眼压时 ,应应用 Goldm ann压平眼压计校正     

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.     

Effect of corneal thickness on intraocular pressure measurements with the Pascal dynamic contour,Canon TX‐10 non‐contact and Goldmann applanation tonometers in healthy subjects

Purpose: To investigate the effects of central corneal thickness (CCT) on intraocular pressure (IOP) measurements of the Pascal dynamic contour tonometry (DCT), Canon TX‐10 non‐contact tonometry (NCT) and Goldmann applanation tonometry measurements (GAT) in healthy subjects. Methods: IOP values of 135 eyes with normal corneas of 135 healthy volunteers were determined by DCT, NCT and by GAT. The CCT was measured using an ultrasonic pachymeter after all IOP determinations had been made. Results: When DCT measurements were compared (IOP = 17.52 ± 2.0 mmHg) with NCT measurements (IOP = 16.54 ± 2.77 mmHg) and GAT measurements (IOP = 15.07 ± 2.35 mmHg), DCT measurements were significantly higher than NCT and GAT (p < 0.001). There was a significant correlation between CCT with both NCT (r = 0.260, p = 0.003) and GAT measurements (r = 0.257, p = 0.005). There was a weak correlation that was not statistically significant between CCT and DCT (r = 0.160, p = 0.079). Conclusion: The IOP measurements with DCT seem to be less dependent on CCT. NCT appears to be more affected by variation in CCT than GAT.     

Assessment of intraocular pressure measured by Reichert Ocular Response Analyzer, Goldmann Applanation Tonometry, and Dynamic Contour Tonometry in healthy individuals

AIM: To investigate the accuracy of intraocular pressure (IOP) as measured by a Reichert Ocular Response Analyzer (ORA), as well as the relationship between central corneal thickness (CCT) and IOP as measured by ORA, Goldmann applanation tonometry (GAT), and dynamic contour tonometry (DCT). METHODS: A total of 158 healthy individuals (296 eyes) were chosen randomly for measurement of IOP. After CCT was measured using A-ultrasound (A-US), IOP was measured by ORA, GAT, and DCT devices in a randomized order. The IOP values acquired using each of the three tonometries were compared, and the relationship between CCT and IOP values were analyzed separately. Two IOP values, Goldmann-correlated IOP value (IOPg) and corneal-compensated intraocular pressure (IOPcc), were got using ORA. Three groups were defined according to CCT: 1) thin cornea (CCT<520μm); 2) normal-thickness cornea (CCT: 520–580μm); and 3) thick cornea (CCT>580μm) groups. RESULTS: In normal subjects, IOP measurements were 14.95±2.99mmHg with ORA (IOPg), 15.21±2.77mmHg with ORA (IOPcc), 15.22±2.77mmHg with GAT, and 15.49±2.56mmHg with DCT. Mean differences were 0.01±2.29mmHg between IOPcc and GAT (P>0.05) and 0.28±2.20mmHg between IOPcc and DCT (P>0.05). There was a greater correlation between IOPcc and DCT (r=0.946, P=0.000) than that between IOPcc and GAT (r=0.845, P=0.000). DCT had a significant correlation with GAT (r=0.854, P=0.000). GAT was moderately correlated with CCT (r=0.296, P<0.001), while IOPcc showed a weak but significant correlation with CCT (r=?0.155, P=0.007). There was a strong negative correlation between CCT and the difference between IOPcc and GAT(r=-0.803,P=0.000), with every 10μm increase in CCT resulting in an increase in this difference of 0.35mmHg. The thick cornea group (CCT>580μm) showed the least significant correlation between IOPcc and GAT (r=0.859, P=0.000); while the thin cornea group (CCT＜520μm) had the most significant correlation between IOPcc and GAT (r=0.926, P=0.000). The correlated differences between IOPcc and DCT were not significant in any of the three groups (P>0.05). CONCLUSION: Measurement of IOP by ORA has high repeatability and is largely consistent with GAT measurements. Moreover, the ORA measurements are affected only to a small extent by CCT, and are likely to be much closer to the real IOP value than GAT.     

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.     

动态轮廓眼压计与Goldmann压平眼压计及非接触眼压计测量眼压的对比研究

目的探讨动态轮廓眼压计(DCT)与Goldmann压平眼压计(GAT)及非接触眼压计(NCT)测量眼压的准确性,并比较三种眼压计测量结果与中央角膜厚度(CCT)的相关性。设计前瞻性、比较性病例系列。研究对象连续选取90例(90眼)10~76岁正常人。方法采用KONAN非接触式角膜内皮镜测量CCT后,对所有入选者单眼以随机顺序采用Pascal型DCT、GAT及Topcon型NCT测量眼压。测量结果两两比较,并将眼压值与CCT进行直线回归分析。主要指标眼压值,Pearson相关系数。结果 90例正常人DCT眼压平均值(17.33±2.71 mm Hg)明显高于GAT(14.27±2.81 mm Hg)(P=0.000)及NCT(14.67±2.93 mm Hg)(P=0.000),平均差异分别为(3.06±2.01)mm Hg和(2.67±2.20)mm Hg;GAT与NCT之间平均差异为(-0.39±2.29)mm Hg(P=0.105)。DCT与GAT眼压值之间相关系数r=0.736(P=0.000);与NCT眼压值之间相关系数r=0.699(P=0.000)。GAT、NCT眼压值与CCT均明显相关(r=0.370,P=0.000;r=0.508,P=0.000);DCT眼压值与CCT无明显相关性(r=0.051,P=0.639)。DCT和GAT的差值与年龄无明显相关性(r=0.064,P=0.052)。结论 DCT测量的眼压值虽高于GAT及NCT,但不受CCT的影响,可能较GAT和NCT测量的眼压值更接近真实值。     

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）     

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 influence of soft contact lenses on the intraocular pressure measurement

Purpose

To evaluate the influence of silicone hydrogel contact lenses on the intraocular pressure (IOP) measurement using Goldmann applanation tonometry (GAT), non-contact tonometry (NCT), and Pascal dynamic contour tonometry (DCT).

Methods

We included in the study 40 eyes of 40 patients who did not have any ocular or systemic diseases or contraindications to contact lens use. We measured and recorded the IOP values of each patient using NCT without and with contact lenses (groups 1 and 2, respectively), using DCT without and with contact lenses (groups 3 and 4, respectively), and using GAT without contact lenses (group 5).

Results

The mean IOP value of group 1 was 14.55±2.95 mm Hg and 13.92±2.58 mm Hg in group 2. We detected no statistically significant difference between group 1 and group 2 (P=0.053). The mean IOP values for group 3 and group 4 were 16.26±2.33 mm Hg and 15.19±2.40 mm Hg, respectively. We detected a statistically significant difference between groups 3 and 4 (P=0.005). Group 5''s mean IOP value was 12.97±2.65 mm Hg. IOP values measured with DCT were statistically significantly higher compared with IOP values measured with NCT and GAT (P<0.0001 and P<0.0001, respectively). Additionally, IOP values measured with NCT were statistically significantly higher compared with IOP values measured with GAT (P<0.0001).

Conclusion

According to the results of our study, silicone hydrogel soft contact lens use does not significantly affect IOP values measured with NCT, but it affects IOP values measured with DCT.     

The effect of contact lens-induced corneal edema on Goldmann applanation tonometry and dynamic contour tonometry

Purpose  To evaluate the effect of contact lens-induced corneal edema on intraocular pressure (IOP) measurements using Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT) in Asian subjects. Participants  The study included 40 eyes of 20 normal volunteers with no evidence of ocular disease. Methods  Forty eyes of 20 healthy volunteers were required to wear soft contact lenses for 2 hours to induce corneal swelling. Central corneal thickness (CCT) and IOP were measured before and immediately after contact lens wear using specular microscope, GAT, and DCT. The IOP measurements by GAT and DCT were compared. The changes in the CCT and the IOP measurements after wearing contact lenses were assessed. Results  The mean CCT of the 40 eyes evaluated was 532.6 ± 31.6 μm. The mean IOP was 11.78 ± 2.04 mmHg for the GAT and 14.46 ± 1.89 mmHg for the DCT, and the difference was statistically significant (P < 0.001). After wearing contact lenses, the mean CCT was 553.2 ± 34.3 μm, which was 20.6 ± 12.9 μm greater than before wearing them (P < 0.001). The mean IOP measurements of the GAT and DCT were decreased after wearing the contact lenses. The mean decrease of the GAT values was 0.43 ± 1.95 mmHg, which was not statistically significant (P = 0.175). However, the mean decrease of the DCT readings, which was 0.75 ± 1.74 mm Hg, was statistically significant (P = 0.010). Conclusion  The IOP measurements with DCT were significantly higher than those with GAT in healthy Asian eyes. Although the mean IOP measurements of both the GAT and the DCT were decreased in the edematous cornea, IOP measurements of the DCT were more affected by corneal edema than were the GAT. The authors have no proprietary, commercial, or financial interests in any of the products described in this study.     

Dynamic contour tonometry versus Goldmann applanation tonometry: a comparative study

Background Various sources of error, including central corneal thickness (CCT) and structural corneal rigidity, have been proposed for Goldmann applanation tonometry (GAT). The Pascal dynamic contour tonometer (DCT) is a novel device designed for intraocular pressure (IOP) measurements assumed to be largely independent of CCT and corneal curvature. We compared DCT with GAT in eyes with normal corneas of various thickness.Methods We prospectively measured IOP using DCT and GAT in random order in 100 eyes of 100 subjects (M:F=46:54; mean age 42±19, range 23–88 years).Results Mean DCT values were about 1mmHg higher than GAT readings (16±3 vs 15±3 mmHg, p=0.001). Bland–Altman analysis of individual pairs of DCT and GAT measurements revealed a bias of –1.0 mmHg [95% confidence interval (CI): ±1.2]. Neither GAT nor DCT showed a significant correlation with CCT (533±48, range 399–641 m).Conclusions In eyes with normal corneas, DCT allows suitable and reliable IOP measurements which are in good concordance with GAT. Comparison of DCT with intracameral manometry is desirable in the future.