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。     

三种眼压计在准分子激光原位角膜磨镶术后的应用比较

目的评价三种不同眼压计在近视准分子激光原位角膜磨镶术后的应用。方法对近视33例66眼和LASIK术后43例86眼分别用非接触眼压计(non—contact tonometer NCT)，Goldmann压平眼压计(Godmann applanalion tonometer，GAT)和Tono-Pen压平眼压计测量眼压(Tono—Pen眼压计测量角膜中央和颞下距角膜缘1．5～2mm处的眼压)，同时测角膜中央及颞下方的厚度。结果用三种方法测得的近视眼LASIK术后的眼压测量值均明显低于正常近视眼。两组均为Tono—Pen和NCT、与GAT测量值呈正相关，LASIK术后中央Tbno—Pen眼压测量值与术前GAT呈正相关。眼压与角膜厚度的关系：近视眼组，NCT与角膜中央厚度呈正相关；GAT和Tono—Pen与角膜厚度无相关性。LASIK术后组，GAT和NCT与角膜厚度呈正相关；Tono-Pen与角膜中央厚度无相关性。结论LASIK术后眼压测量值下降。Tono—Pen测量IOP不受角膜厚度的影响，可应用于LASIK术后等角膜表面不平者。     

角膜中央厚度和曲率对非接触式眼压计测量值的影响

目的研究角膜中央厚度、曲率对非接触式眼压计(NCT)测量值的影响.方法测量PRK或LASIK术前102例(204眼)患者的角膜中央厚度、角膜曲率、眼压,并将测量结果进行相关及回归统计学处理.结果角膜中央厚度与NCT测量值的相关系数r=0.4846,P＜0.001,有高度统计学意义;角膜曲率与NCT测量值的相关系数r=0.0687,P＞0.05,无统计学意义.结论角膜中央厚度与NCT测量值呈正相关,角膜曲率与NCT测量值之间无相关关系.     

动态轮廓眼压计与非接触式眼压计的比较

目的探讨中央角膜厚度和角膜曲率对轮廓动态眼压计以及非接触式眼压计眼压测量结果的影响。方法接受准分子激光原位角膜磨镶术(LASIK)的近视患者27例(54只眼),分别于术前和术后第4周使用非接触式眼压计(NCT)和动态轮廓眼压计(DCT)进行眼压测量。多元线性相关分析研究NCT、DCT测量值和角膜曲率及角膜中央厚度(CCT)之间的相关性。结果LASIK术后NCT测量值降低,而DCT测量值和术前比较差异则无统计学意义。角膜曲率、CCT和NCT读数呈线性相关,而与DCT读数无关。结论DCT测量眼压不受角膜曲率和中央角膜厚度影响,因此更适合于正常眼以及曾经接受角膜屈光手术眼的眼压测量。     

动态轮廓眼压计与压平眼压计的比较

目的:评价和比较动态轮廓眼压计和Goldmann压平眼压计测得的LASIK手术后眼压值。方法:接受准分子激光原位角膜磨镶术(LASIK)的近视患者34例68眼,分别于术前和术后3mo使用动态轮廓眼压计(Pascal dynamic contour tonometer,PDCT)和Goldmann压平眼压计(the Goldmann applanation tonometer,GAT)进行眼压测量。比较手术前后两种测量方法测得的眼压值的差异。多元线性相关分析研究GAT,PDCT测量值和角膜曲率及角膜中央厚度(CCT)之间的相关性。结果:LASIK手术后GAT测量值较术前低,而PDCT值和术前比较差异则无统计学意义。角膜曲率、CCT和GAT读数呈线性相关,而与PDCT读数无关。结论:GAT测量得到的眼压低于实际值。PDCT测眼压不受角膜曲率和中央角膜厚度影响。     

Diaton眼压计与非接触式眼压计测量眼压的比较

目的比较Diaton眼压计（DT）与非接触式眼压计（NCT）测量眼压的差异。方法分别使用DT和NCT测量患者眼压,对测量值进行统计学分析,多元相关分析研究眼压测量值与年龄、角膜曲率、等效球镜度、中央角膜厚度之间的相关性。结果 DT与NCT的平均眼压测量值分别为（13.81±3.27）mmHg和（15.80±3.48）mmHg,差异有统计学意义（P〈0.05）,二者测量值的相关系数r=0.438,P〈0.05,两种眼压计的测量差值随中央角膜厚度增加而升高;将所有患者依照中央角膜厚度分为3组,NCT测量值在3组间有显著差异,而NCT测量值在3组间无差异;NCT测量值与年龄和中央角膜厚度呈正相关,而DT测量值与年龄、角膜曲率、等效球镜度、中央角膜厚度均不相关。结论 Diaton眼压计测量值不受年龄和中央角膜厚度影响,与非接触式眼压计测量值呈正相关,可应用于临床普查和诊断。     

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。     

动态轮廓眼压计的临床应用

目的 探讨动态轮廓眼压计(OCT)在原发性开角型青光眼(POAG)、高眼压症(OHT)、正常眼压性青光眼(NTG)及正常对照人群眼压和眼压脉动振幅(OPA)测量中的临床应用价值及影响因素.方法 选取POAG、OHT、NTG及正常对照组各30例,分别采用Goldmann压平眼压计(GAT)测量眼压,DCT测量眼压及OPA,并测量中央角膜厚度(CCT)、中央角膜曲率(CCV)以及心率、收缩压、舒张压等指标,以了解这些指标对OPA的影响.各组统计量两两比较采用q检验.各统计量之间的相关分析采用Pearson相关分析,对于多个变量之间的线性关系采用多重线性回归分析.结果 DCT测量POAG、OHT、NTG及对照组的眼压值分别为(21.68±2.02)、(23.37±2.65)、(18.43±3.08)、(17.04±2.07)lnln Hg(1 mm Hg=0.133 kPa);GAT测最的眼压值分别为(21.18±2.95)、(23.28±5.95)、(16.39±3.60)、(14.66±2.27)mm Hg.两者测量结果的差异无统计学意义(t=1.338,1.445,1.682,1.803;P=0.197,0.151,0.136,0.081).POAG、OHT、NTG及对照组的OPA值分别为3.03±1.13,3.53±1.43,2.21±0.55,2.87±0.60,组间比较差异有统计学意义(F=21.311,P=0.000);OPA值与心率、收缩压、舒张压、GAT测量值、CCT均相关,与年龄无明显相关性.结论 DCT测量结果与GAT有良好的一致性,受干扰因素少,可信度高;POAG、NTG、OHT患者和正常人的OPA存在差异,其中NCT患者OPA值明显较低,提示各组间眼内血液动力学状况的差异,OPA可能对青光眼的诊断及治疗具有一定的潜在价值.     

角膜厚度对三种不同眼压计测量的影响

目的:比较采用Goldmann压平眼压计(Goldmann applanation tonometer,GAT)、非接触眼压计(non-contact tonometer,NCT)和Schiotz眼压计(Schiotz tonometer,ST)的眼压(intraoeular pressure,IOP)测量,评估角膜中央厚度(central corneal thickness,CCT)对读数的影响。方法:使用GAT、NCT和ST对所有患者的右眼进行眼压测量。超声角膜厚度测量法测定CCT。所有IOP及CCT测量由同一检查者进行。计算CCT25%(Q1)百分位数和75%(Q3)百分位数值,并通过这种方法将该组分为薄、中、厚角膜亚组。使用Statplus软件进行统计分析。结果:全系列144眼,GAT测量平均IOP为17.4±4.9mmHg,NCT为16.0±5.8mmHg,ST为14.0±4.0mmHg(Friedman方差分析P<0.01)。IOP水平和CCT之间的相关系数NCT为0.787(P<0.01),GAT为0.630(P<0.01),ST为0.565(P<0.01)。ST测量中,纠正的IOP误差和CCT之间的相关性在厚角膜明显弱(r=0.381,P=0.022)。结论:NCT是最易受不同CCT影响的设备。ST读数似乎比GAT和NCT读数受CCT的影响小。特别是在厚角膜,与NCT和GAT相比,ST可以被认为是一个更可靠的仪器。     

Diaton眼压计测量准分子激光原位角膜磨镶术后眼压

目的:通过与非接触式眼压计(non-contact tonometer,NCT)的比较,评价Diaton眼压计(DT)在准分子激光原位角膜磨镶术(laser in situkeratomileusis,LASIK)前后眼压测量中的应用价值。方法:在LASIK术前及术后1mo,分别使用NCT和DT测量患者眼压,使用SPSS13.0统计软件对所得结果进行统计学分析。结果:术后1mo时,NCT眼压测量值较术前下降(5.76±2.31)mmHg,DT眼压测量值则无显著差异(t=0.70,P=0.487);NCT与DT读数测量值差值与术中切削量呈正相关,与术后中央角膜厚度呈负相关。结论:Diaton测量眼压不受角膜厚度的影响,因此更适用于LASIK术后患者的眼压测量。     

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.     

Comparison of ICare tonometer with Goldmann applanation tonometer in glaucoma patients

PURPOSE: To compare the intraocular pressure (IOP) readings taken with the new ICare tonometer and with the Goldmann applanation tonometer (GAT) and to evaluate the influence of central corneal thickness (CCT) on the IOP measurements. PATIENTS AND METHODS: One eye of 178 consecutive patients with primary open-angle glaucoma underwent ultrasonic CCT measurement, followed by IOP evaluation with the GAT and with the ICare tonometer. The deviation of ICare readings from GAT values, corrected according to the Doughty and Zaman formula, was calculated and correlated to CCT by a linear regression model. The agreement between the 2 devices was assessed by use of the Bland-Altman method. RESULTS: The average CCT was 552+/-39 mum. The mean IOP and the mean corrected IOP with GAT were 19.4+/-5.4 mm Hg, and 18.5+/-5.7 mm Hg, respectively. The mean ICare IOP reading was 18.4+/-5.2 mm Hg. The deviations of ICare readings from corrected GAT values were highly correlated with CCT values (r=0.63, P<0.01). Linear regression analysis showed that a CCT change of 10 mum resulted in an ICare reading deviation of 0.7 mm Hg. The Bland-Altman scatter-plot showed a reasonable agreement between the 2 tonometers. CONCLUSIONS: The ICare tonometer can be useful in a routine clinical setting. The IOP readings are quite in accordance with those obtained by GAT. The measurements seemed to be influenced by CCT variations, and thus pachymetry should always be taken into consideration.     

The influence of central corneal thickness and corneal curvature on intraocular pressure measured by tono-pen and rebound tonometer in children

PURPOSE: To find out the effect of central corneal thickness (CCT) and radius of the corneal curvature on intraocular pressure (IOP) measurements using rebound tonometer (RBT) and Tono-Pen in healthy schoolchildren. METHODS: IOP was measured with Tono-Pen and RBT, respectively, in 165 healthy schoolchildren with a mean age 9.8+/-3.1 (range: 7 to 12 y) years. Corneal radius of curvature (in mm) was determined using a keratometer before CCT and IOP measurements. CCT was measured using an ultrasonic pachymeter after all IOP determinations had been made. The effect of CCT, radius of the corneal curvature, and sex on measured IOP was evaluated by linear regression analysis. RESULTS: The mean IOP readings were 17.47+/-2.7 mm Hg using Tono-Pen, and 16.81+/-3.1 mm Hg using RBT. Tono-Pen measured IOP values slightly greater than that of RBT (P=0.006). Mean CCT was found to be 561.37+/-33 microm. A significant association between measured IOP and CCT was found with each device (r=0.220 for the Tono-Pen, r=0.373 for the RBT; P=0.006 for the Tono-Pen and P<0.0001 for the RBT). The IOP increased 2.2 and 3.7 mm Hg for every 100-microm increase in CCT for the Tono-Pen and the RBT, respectively. The relation between IOP and CCT was not different for boys and girls. Mean radius of the corneal curvature readings was 7.68+/-0.41 mm (42.75+/-1.37 D) for both sexes. There was no significant relationship between either the mean corneal curvature readings, or CCT and IOP (r=0.02; P=0.4 for CCT and r=0.01; P=0.5 for IOP). CONCLUSIONS: Both the Tono-Pen and RBT have a systematic error in IOP readings caused by its dependence on CCT. The CCT measurements should be considered to ensure proper interpretation of IOP measurements in children, like in adults. The corneal radius of curvature had no significant effect on measured IOP with each device.     

Assessment of the Pascal dynamic contour tonometer in monitoring intraocular pressure in unoperated eyes and eyes after LASIK

PURPOSE: To assess the performance of the Pascal dynamic contour tonometer (PDCT) (Swiss Microtechnology AG) by comparing it to Goldmann applanation tonometry (GAT) and noncontact air tonometry (NCT) before and after laser in situ keratomileusis (LASIK). SETTING: Vlemma Eye Institute, Athens, Greece. METHODS: Intraocular pressure was measured in 118 eyes before and 1 and 4 weeks after LASIK using GAT, NCT, and the PDCT, which allows direct, digital, transcorneal measurement of intraocular pressure. RESULTS: Preoperatively, central corneal thickness (CCT) correlated with GAT and NCT measurements but not with PDCT measurements. After LASIK, the mean reduction in CCT ranged from -3.0 to -171.0 microm (median 78 microm). The mean GAT measurement dropped by -4.9 mm Hg +/- 2.7 (SD) at 1 week and was -5.4 +/- 3.0 mm Hg at 4 weeks. Similar drops were observed in NCT measurements. The observed post-LASIK changes in GAT and NCT IOP measurements were not directly proportional to the change in CCT, refractive error, or mean keratometric readings. The preoperative and postoperative PDCT measurements did not differ significantly. CONCLUSIONS: The structural corneal changes induced by LASIK appeared to influence GAT and NCT measurements but not PDCT measurements. Therefore, PDCT may be better suited for monitoring IOP in unoperated eyes and in eyes that have had LASIK.     

Influence of corneal structure, corneal responsiveness, and other ocular parameters on tonometric measurement of intraocular pressure

PURPOSE: To estimate the relationships between ocular parameters and tonometrically measured intraocular pressure (IOP), to determine the influence of ocular parameters on different instrument measurements of IOP, and to evaluate the association of ocular parameters with a parameter called hysteresis. METHODS: Patients presenting at a glaucoma clinic were recruited for this study. Subjects underwent IOP measurement with the Goldmann applanation tonometer (GAT), the TonoPen, and the Reichert Ocular Response Analyzer (ORA), and also measurements of central corneal thickness (CCT), axial length, corneal curvature, corneal astigmatism, central visual acuity, and refractive error. Chart information was reviewed to determine glaucoma treatment history. The ORA instrument provided a measurement called corneal hysteresis. The association between measured IOP and the other ocular characteristics was estimated using generalized estimating equations. RESULTS: Among 230 patients, IOP measurements from the TonoPen read lowest, and ORA read highest, and GAT measurements were closest to the mean IOP of the 3 instruments. In a multiple regression model adjusting for age, sex, race, and other ocular characteristics, a 10 microm increase in CCT was associated with an increase of 0.79 mm Hg measured IOP in untreated eyes (P<0.0001). Of the 3 tonometers, GAT was the least affected by CCT (0.66 mm Hg/10 mum, P<0.0001). Hysteresis was significantly correlated with CCT with a modest correlation coefficient (r=0.20, P<0.0007). CONCLUSIONS: Among parameters related to measured IOP, features in addition to CCT, such as hysteresis and corneal curvature, may also be important. Tonometric instruments seem to be affected differently by various physiologic characteristics.     

Inter-instrument agreement and influence of central corneal thickness on measurements with Goldmann, pneumotonometer and noncontact tonometer in glaucomatous eyes

PURPOSE: This study was conducted to compare the intraocular pressure (IOP) measurements by the Goldman applanation tonometer (GAT), non contact tonometer (NCT) and the ocular blood flow (OBF) pneumotonometer in different IOP ranges in glaucomatous eyes. The effect of central corneal thickness (CCT) on IOP measurement in chronic glaucomatous eyes using the three different tonometers was also evaluated. MATERIALS AND METHODS: IOP measurements of 130 eyes of primary glaucoma patients were performed using GAT by an ophthalmologist while NCT and OBF-pneumotonometer measurements were performed by an experienced optometrist. The IOP values were compared amongst the three instruments in the three different IOP ranges (0-18 mmHg, > 18 to 25 mmHg, > 25 mmHg). CCT was also measured in all patients. RESULTS: The mean of paired difference between GAT and NCT was 0.9 +/- 3.1 mmHg while that between GAT and OBF-pneumotonometer was 0.3 +/- 3.4 mmHg. The OBF-pneumotonometer and NCT were more affected by corneal thickness (0.41 mmHg and 0.4 mmHg / 10 micro corneal thickness respectively) while GAT was the least affected by corneal thickness (0.3 mmHg / 10 micro corneal thickness) though the difference was not statistically significant ( P =0.42). CONCLUSION: With appropriate correction for corneal thickness the NCT and OBF-pneumotonometer can be used as reliably as GAT in following up glaucomatous patients.     

The influence of corneal thickness and curvature on the difference between intraocular pressure measurements obtained with a non-contact tonometer and those with a Goldmann applanation tonometer

PURPOSE: The influence of corneal thickness and curvature on the difference between intraocular pressure (IOP) measurements obtained with a non-contact tonometer (NCT) and those with a Goldmann applanation tonometer (GAT) was studied. METHODS: The corneal thickness and curvature were obtained in 230 eyes of 115 subjects. The correlation between them and ratios of measurement with NCT to that with GAT ([NCT/GAT]) were examined. RESULTS: [NCT/GAT] and corneal thickness showed a significant positive correlation (r = 0.556, p < 0.01), but, the correlation between [NCT/GAT] and the radius of corneal curvature was not statistically significant (r = -0.035, p = 0.30). CONCLUSION: The thick cornea has more influence on the measurement with NCT than GAT, because IOP is measured with NCT over a wider applanation area. The corneas with steeper curvature also cause higher corneal rigidity and produce more overestimation of NCT measurement, while they have stronger capillary attraction of the precorneal tear film for the GAT tip and also produce overestimation of GAT measurement. As a result, [NCT/GAT] was believed to be not influenced by the corneal curvature.