Pressure phosphene tonometry versus Goldmann applanation tonometry for measuring intraocular pressure before and after LASIK

PURPOSE: To compare pressure phosphene tonometry with Goldmann applanation tonometry for measuring intraocular pressure (IOP) before and after LASIK. METHODS: Forty-three (18 men and 25 women) consecutive healthy patients underwent complete pre- and postoperative LASIK ophthalmologic assessments including manifest and cycloplegic refraction, keratometry, and central corneal thickness. Three repetitive sets of pressure phosphene tonometry and Goldmann applanation tonometry measurements were performed the day before and 3 months following uneventful LASIK. RESULTS: Mean preoperative spherical equivalent refraction was -4.70 +/- 2.50 diopters (D) (range: -1.50 to -12.90 D) and mean preoperative keratometry was 43.95 +/- 1.08 D. After LASIK, spherical equivalent refraction was +0.23 +/- 0.11 D and mean keratometry was 39.46 +/- 2.28 D. Preoperative pressure phosphene tonometry (12.16 +/- 1.58 mmHg) and Goldmann applanation tonometry (12.01 +/- 1.55 mmHg) IOP measurements were similar. Postoperative IOP was 10.30 +/- 1.16 mmHg with Goldmann applanation tonometry and 12.20 +/- 1.62 mmHg with pressure phosphene tonometry. The postoperative IOP difference between Goldmann applanation tonometry and pressure phosphene tonometry was 0.15 +/- 1.12 mmHg (P = .41). The mean change in pachymetry after LASIK was 68.73 +/- 73 microm. The change in Goldmann applanation between preoperative and postoperative LASIK values was 1.71 +/- 1.43 mmHg (P < .0001), a change that was strongly correlated with changes in corneal thickness (R = 0.75, P < .0001) and keratometry (R = 0.72, P < .0001). No such correlations were found with pressure phosphene tonometry. CONCLUSIONS: Goldmann applanation tonometry-measured IOP decrease after LASIK is strongly correlated with a decrease in central corneal thickness and changes in keratometry, whereas pressure phosphene tonometry-measured IOP is independent of corneal thickness. Pressure phosphene tonometry appears to be a more reliable method for recording tonometry in these patients.     

Transpalpebral measurement of intraocular pressure using the Diaton tonometer versus standard Goldmann applanation tonometry

Background  

Diaton transpalpebral tonometry is a new version of TGDc-01 transpalpebral tonometry. The aim of this study is to evaluate the reliability of this method, and to compare the results with those of corrected Goldmann applanation tonometry (c-GAT), which is the “gold standard” for the clinical measurement of IOP.     

Intraocular pressure difference in Goldmann applanation tonometry versus Perkins hand-held applanation tonometry in overweight patients

Objective

To analyze the increase in intraocular pressure (IOP) caused by anatomic and physiologic factors in overweight patients when using Goldmann applanation tonometry.

Design

A prospective cohort study.

Participants

Seventy average-weight individuals who had no difficulties with IOP measurements at the slit lamp and 12 obese patients with suspected glaucoma who could position the head at the slit lamp only with great effort participated.

Intervention

The authors compared IOP values between slit-lamp-mounted Goldmann applanation tonometry and Perkins hand-held tonometry.

Main outcome measure

The difference in Goldmann and Perkins IOP measurements was examined.

Results

In the group of obese patients, the mean IOP was 20.9 ± 2.28 mmHg (mean ± standard deviation; range, 18–26 mmHg) for the right eye and 21.4 ± 3.16 mmHg (range, 16–28 mmHg) for the left eye when determined by Goldmann tonometry and 16.3 ± 2.39 mmHg (range, 13–20 mmHg) for the right eye and 16.3 ± 2.42 (range, 11–19 mmHg) for the left eye when determined by Perkins tonometry. The mean decrease was 4.5 ± 1.3 mmHg (range, 3–7 mmHg) for the right eye and 4.9 ± 1.9 mmHg (range, 2–9 mmHg) for the left eye. In the control group, the mean difference between the two types of tonometers for the right eye was 0.34 ± 0.69 mmHg and for the left eye was 0.33 ± 0.82 mmHg. Patients who had a falsely elevated IOP on Goldmann tonometry had an average body mass index of 34 ± 3.82 (range, 28.5–41.9); most were female (5:1 ratio).

Conclusion

The authors believe simultaneous breath-holding and thorax compression, with subsequent increase in venous pressure, may be a causative factor for transitory elevations of IOP. Perkins tonometry in obese patients may help avoid a false diagnosis of glaucoma caused by transitory elevations in IOP.     

Transpalpebral measurement of intraocular pressure using the TGDc-01 tonometer versus standard Goldmann applanation tonometry

Background A recently developed digital tonometer for transpalpebral intraocular pressure (IOP) measurement, distributed by Corneal, Inc., allows the noninvasive measurement of IOP for screening purposes.Method We measured the IOP of 218 eyes in 109 patients of the Interdisciplinary Uveitis Center of the University of Heidelberg with intact corneal epithelium. IOPs were measured first with the TGDc-01 tonometer, and then by means of Goldmann tonometry. IOPs were recorded by two independent examiners. The mean of three measurements obtained with the TGDc-01 was taken, whereas only one measurement was performed with the Goldmann tonometer.Results The mean difference between the TGDc-01 and Goldmann measurements was 3.7 mmHg. The standard deviation of the differences was ±4.06 mmHg. Thus measurements acquired with the TGDc-01 may range 4.4 mmHg above or 11.8 mmHg below the values given by Goldmann tonometry.Conclusion The IOP values obtained with the TGDc-01 were in poor agreement with Goldmann tonometry. We found a higher variation as well as a bias towards lower IOP values with the TGDc-01. It is a question of clinical judgement as to how far these deviating measurements can be accepted for screening purposes. Because the IOPs obtained with the TGDc-01 are generally lower and less accurate than those obtained with the Goldmann tonometer we believe that the TGDc-01 is not a reliable tool for IOP measurement in clinical routine.This work was presented at the 101st meeting of the German Society of Ophthalmology, Berlin, 2003     

Comparison of intraocular pressure measured by Pascal dynamic contour tonometry and Goldmann applanation tonometry

AIMS: To compare the intraocular pressure (IOP) measurements obtained using the Pascal dynamic contour tonometer (PDCT) with the standard Goldmann applanation tonometer (GAT) and to correlate these with central corneal thickness (CCT) in patients with normal corneas. METHODS: A prospective, masked, comparative case series of 116 eyes from patients attending a glaucoma clinic. IOP was measured with PDCT by one examiner and with GAT by a masked, independent examiner. A mean of six CCT readings was used for analysis. RESULTS: IOP measured by the two instruments correlated significantly (r=0.77; P<0.0001). IOP measured by GAT correlated strongly with CCT (r=0.37, P=0.0001) whereas the relationship between IOP measured by PDCT and CCT approached significance (r=0.17, P=0.073). The differences between GAT and PDCT measured IOP also correlated strongly with CCT (r=0.37, P<0.0001). The 95% limits of agreement between GAT and PDCT were +/-4.2 mmHg. Dividing the eyes into three groups on the basis of CCT, demonstrated those in the thickest tertile showed a poorer agreement between instruments and the GAT measured significantly higher IOP in this group (P=0.003) while the PDCT showed no significant differences with different CCTs (P=0.37). CONCLUSION: Demonstration of the relative independence of PDCT IOP measurements from CCT supports a potential clinical role for this instrument, particularly for subjects with CCT outside the normal range.     

Oculab Tono-Pen, Goldmann applanation tonometry, and pneumatic tonometry for intraocular pressure assessment in gas-filled eyes

We performed 84 intraocular pressure measurements with the Oculab Tono-Pen, Goldmann applanation tonometer, and pneumatic tonometer in 47 eyes that had undergone pars plana vitrectomy and gas-fluid exchange. Measurements made by using the Tono-Pen were accurate when compared to those made by Goldmann tonometry (mean difference, 0.74 mm Hg). In a subset of eyes with increased intraocular pressure (greater than or equal to 25 mm Hg), the Tono-Pen provided measurements similar to those made by Goldmann applanation tonometry (P greater than .60), with only three of 39 readings (8%) underestimating the Goldmann pressure by more than 3 mm Hg. Pneumatic tonometry significantly underestimated the intraocular pressure in eyes with increased pressure (P less than .001), with 20 of 39 readings (51%) underestimating the Goldmann pressure by 5 mm Hg or more.     

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.     

Measurement of intraocular pressure in LASIK and LASEK patients using the Reichert Ocular Response Analyzer and Goldmann applanation tonometry

PURPOSE: To determine the efficacy of the Reichert Ocular Response Analyzer (ORA) to measure intraocular pressure (IOP) following corneal laser refractive surgery. METHODS: Intraocular pressure was measured using Goldmann applanation tonometry preoperatively and 3 months following LASIK and LASEK for all levels of myopia and low levels of hyperopia. In LASIK eyes, 120-microm flaps were cut using the Hansatome XP. The ORA was used to measure Goldmann correlated IOP and corneal compensated IOP 3 months postoperatively. Postoperative central corneal thickness, hysteresis, and corneal curvature were assessed to determine their relationship with postoperative change in Goldmann applanation tonometry IOP. Efficacy of ORA IOP measurement was analyzed by comparing Goldmann applanation tonometry IOP with Goldmann correlated IOP. RESULTS: LASEK was performed on 35 eyes, and LASIK was performed on 90 eyes. In the LASIK group, mean Goldmann applanation tonometry IOP decreased 3.7+/-2.3 mmHg postoperatively (P=.00). Postoperative Goldmann applanation tonometry did not differ significantly (P=.06) from postoperative ORA Goldmann correlated IOP (10.2+/-2.1 mmHg). In the LASEK group, mean Goldmann applanation tonometry IOP decreased 3.9+/-2.3 mmHg (P=.00). Postoperative Goldmann applanation tonometry did not differ significantly (P=.6) from postoperative ORA Goldmann correlated IOP (10.7+/-2.5 mmHg). Postoperative decrease in Goldmann applanation tonometry IOP did not correlate with age, ablation depth, pre- and postoperative central corneal thickness or corneal hysteresis, or postoperative decrease in corneal curvature. CONCLUSIONS: Intraocular pressure measurements were similar using both the ORA Goldmann correlated IOP and Goldmann applanation tonometry following keratorefractive surgery.     

Diurnal variation of central corneal thickness and Goldmann applanation tonometry estimates of intraocular pressure

PURPOSE: To determine whether there is a temporal relationship between the diurnal variation of central corneal thickness (CCT) and intraocular pressure (IOP) by Goldmann applanation tonometry in young normal human participants in vivo. METHODS: Twenty-five eyes of 25 young healthy normal participants were examined in a prospective observational cross-sectional study. IOP, CCT and corneal curvature were measured using standard clinical techniques over a 24-hour period, and the temporal interrelationships between these parameters were examined. RESULTS: The overnight change in IOP measured by Goldmann tonometry was 3.1+/-2.4 mm Hg (P<0.001), CCT was 20.1+/-10.9 mum (P=0.016), with no statistical change in central corneal curvature (0.05 mm, P=0.477, paired t test with Bonferroni correction). Both IOP and CCT were highest on awakening at 7:00 then dropped rapidly to baseline levels by 9:00 (linear mixed models), and these two parameters were highly correlated (r=0.978, P<0.001). After 9:00, there was no correlation between these parameters (r=-0.453, P=0.260). CONCLUSIONS: The results of this study have highlighted a potential link between the diurnal variation of CCT and the accuracy of Goldmann tonometry estimates of IOP during the first 2 hours after awakening. Clinicians should be wary of using Goldmann tonometry to estimate IOP until the overnight increase in CCT has resolved.     

Effect of corneal astigmatism on intraocular pressure measurement using ocular response analyzer and Goldmann applanation tonometer

Purpose  

To assess the effect of corneal astigmatism on intraocular pressure (IOP) measurements using an Ocular Response Analyzer (ORA) and a Goldmann applanation tonometer (GAT).     

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。     

Changes in corneal biomechanics and intraocular pressure following Femto-LASIK using Goldman applanation tonometry and ocular response analyzer

AIM:To compare intraocular pressure(IOP)measurements before and after laser in situ keratomileusis(LASIK)with a femtosecond laser for flap creation using ocular response analyzer(ORA)and Goldmann applanation tonometry,and to identify factors that may influence the preoperative and postoperative IOP.METHODS:A prospective study conducted on myopic patients who underwent LASIK using a femtosecond laser for flap fashioning.Enrolled patients were evaluated preoperatively,6 wk and 3 mo postoperatively for manifest refraction(MR),keratometric(K)readings and central corneal thickness(CCT)using a scheimpflug-based topography.Corneal resistance factor(CRF),corneal hysteresis(CH),Goldmann correlated IOP(IOPg)and corneal compensated IOP(IOPcc)were measured using ORA besides IOP assessment by Goldman applanation tonometry(GAT).RESULTS:There was a statistically significant decrease in measures of IOPg by 3.35±0.83 mm Hg,followed by GAT which decreased by 2.2±0.44 mm Hg,and the least affected by operation was IOPcc which decreased only by 0.87±0.1 mm Hg after 6 wk.After 3 mo follow up there was a statistically significant decrease in IOPcc which decreased only by 0.76±0.4 mm Hg,followed by IOP GAT by 1.6±0.5 mm Hg,and the most affected by operation was IOPg which decreased by 2.3±0.3 mm Hg.Correspondingly,there was a statistically significant decrease in CH and CRF after 6 wk and 3 mo.At 3 mo,the preoperative MR and preoperative GAT were prominent significant predictors of the postoperative GAT changes.The prediction equation was subsumed.CONCLUSION:IOP measurements and corneal biomechanical factors reduce significantly after LASIK with a femtosecond laser for flap creation.The IOPcc values are less influenced by changes in corneal properties than IOPg and GAT,indicating that IOPcc may provide the most reliable measurement of IOP after this procedure.     

Goldmann applanation versus hand-applanation and Schiötz indentation tonometry

Summary For evaluation of hand-applanation tonometry comparative measurements of intraocular pressure have been carried out using the Goldmann applanation tonometer, the Draeger and Perkins hand-applanation tonometers and the Schiötz indentation tonometer. A series of 52 eyes has been tested. The statistical analysis was based on the Goldmann tonometry as a reference system. The hand-applanation tonometers were found to be in satisfactory agreement with the Goldmann tonometer, whereas the Schiötz tonometer gave significantly low values in the pressure range considered.

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Zusammenfassung Zur klinischen Beurteilung der Handapplanationstonometrie wurden vergleichende Messungen des intraokularen Druckes mit dem Applanationstonometer nach Goldmann, den Handapplanationstonometern nach Draeger und Perkins sowie mit dem Schiötz-Tonometer durchgeführt. Die Vergleichsmessungen erfolgten an 52 Augen. Die Ergebnisse der Goldmann-Tonometrie wurden in der statistischen Auswertung als Bezugssystem den anderen Tonometern gegenübergestellt. Hierbei fanden sich die Handapplanations-tonometer nach Perkins und Draeger in guter Übereinstimmung mit der Goldmann-Tono-metrie, während die Schiötztonometrie im untersuchten Druckbereich signifikant zu niedrige Werte ergab.

     

新型非接触式眼压分析仪ORA与Goldmann压平眼压计的比较

目的比较新型非接触式眼压分析仪ORA与Goldmann压平式眼压计测量眼压的差异,以评价ORA眼压测量仪在临床眼压测量中的应用价值。方法本院门诊127例237眼分别由专人进行非接触眼压测量仪ORA与Goldmann压平式眼压计测量,并同时用超声角膜测厚仪测量角膜厚度。结果127例病人237眼,Goldmann压平眼压值和ORA直接测量结果（IOPG）分别为（17.94±6.50）mmHg和（18.88±7.93）mmHg,两者比较差异有显著统计学意义（P=0.000）;正常人群平均角膜厚度为（546.19±36.34）μm,经角膜厚度-眼压公式校正IOPG平均值为17.42±3.92mmHg,ORA经自带软件处理后的眼压值（IOPcc）平均为（17.50±4.38）mmHg,两者比较差异无统计学意义（P=0.681）,IOPG校正前两者比较差异有统计学意义（P=0.024）。结论新型非接触式眼压分析仪ORA的直接测量值与Goldmann压平眼压计的测量值相近略高,ORA的测量分析值IOPcc是排除角膜因素影响更接近真实的眼压结果。     

Comparison of Proview phosphene tonometry with Goldmann applanation tonometry

BACKGROUND: To compare intraocular pressures obtained using a handheld pressure phosphene tonometer (PPT) (Proview, Bausch & Lomb Pharmaceuticals, Inc., Tampa, Fla.) with Goldmann applanation tonometry. METHODS: Comparative case series of 30 randomly selected patients. RESULTS: The readings obtained with the pressure phosphene tonometer display a higher mean and a larger standard deviation than those obtained with the Goldmann applanation tonometer (GAT). Differences between PPT and GAT readings tended to decrease as a function of increased Goldmann levels. The relation of Proview and Goldmann readings (r = 0.32) and the scatterplot were not consistent with the hypothesis that the 2 methods are equivalent. INTERPRETATION: Our results indicate that the pressure phosphene-type handheld tonometry method, which does not appear to provide an accurate and consistent measure of intraocular pressure, is substantially less reliable than the Goldmann method.     

Clinical evaluation of applanation resonance tonometry: a comparison with Goldmann applanation tonometry

PURPOSE: The purpose of this study was to calibrate and evaluate the precision of the new applanation resonance tonometry (ART) in a clinical study designed in accordance with the International Standard Organization's requirements. METHODS: This was a prospective, randomized, single-center study, where healthy volunteers and patients participated. A total of 153 eyes were divided into 3 groups with respect to their intraocular pressure (IOP) at screening: <16 mm Hg, 16 to 23 mm Hg, and >23 mm Hg. IOP was measured with Goldmann applanation tonometry (GAT) as reference method and by ART in both a biomicroscope (ARTBiom) and a handheld (ARTHand) setup with a 10-minutes pause between methods. The mean of 6 readings was regarded as one measurement value. RESULTS: Mean age of the subjects was 59 years (range 20 to 87 y). GAT showed a mean IOP of 20.0 mm Hg (range 8.5 to 43.5 mm Hg, n=153). The precision was 2.07 mm Hg for ARTBiom and 2.50 mm Hg for ARTHand, with a significant dependency for age as compared with GAT. Measurement order produced a decreasing IOP with a mean of 2.3 mm Hg between the first and last method. CONCLUSIONS: The precision obtained in both ARTBiom and ARTHand was within the limits set by the International Standard Organization standards for tonometers. The standardized procedure and the stability of the biomicroscope setup resulted in a slightly better precision as compared with the handheld setup. Despite a 10-minutes pause between measurements, the order was a significant factor, possibly because the patients were more apprehensive at the first measurement.