Accuracy of the Tonosafe disposable tonometer head compared to the Goldmann tonometer alone

PURPOSE: To assess the accuracy of the Tonosafe disposable prism tonometer head via a randomised controlled prospective trial. METHODS: The intraocular pressure (IOP) of 69 patients (31 men, 38 women) involving 137 eyes was measured using both the Tonosafe disposable and the Goldmann tono-meter head. The average age of patients was 66.5 years (range 23-93 years). The two examiners (PM and SL) who performed tonometry were masked while a separate observer read the IOP measurements. The order was randomised between Tonosafe and Goldmann devices. The minimum interval between the two measurements was 15 min. Patients with corneal and external diseases were excluded from the study. RESULTS: The mean IOP using the Goldmann tonometer head was 17.44 +/- 4.97 mmHg. The mean IOP using the Tonosafe disposable head was 17.58 +/- 5.03 mmHg. The mean difference was 0.14 +/- 1.73 mmHg (95% CI -0.44, 0.16, P= 0.36). Subgroup analysis on eyes with IOP > 21 mmHg showed the Tonosafe disposable head was on average 0.15 +/- 2.40 mmHg higher than the Goldmann tonometer head. There was a high level of correlation between the IOPs obtained with the Goldmann and Tonosafe heads. Pearson's coefficient of correlation was 0.94 (P < 0.0001). CONCLUSION: The Tonosafe disposable prism head was found to be accurate in IOP measurement, even in the higher range.     

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     

Evaluation des mobilen TGDc-01-Tonometers und Vergleich mit dem Applanationstonometer nach Goldmann

PURPOSE: The aim of this study was to evaluate patients' acceptance and intraocular pressure (IOP) readings of a new digital mobile tonometer (TGDc-01) and compare it to Goldmann applanation tonometry.METHOD: Measurements repeated five times with the TGDc-01 and three times with Goldmann tonometry were performed in 100 eyes of 100 patients by two independent investigators. Patients' acceptance of both techniques was evaluated by a visual analogue scale (VAS).RESULTS: The mean IOP with the TGDc-01 yielded 15.4 mmHg for investigator 1 and 12.7 mmHg for investigator 2 (range: 4-43 mmHg). Results of the measurements with Goldmann tonometry showed 17.6 mmHg for investigator 1 and 17.3 mmHg for investigator 2 (9-42 mmHg). The IOP difference of the two tonometry methods was highly significant (p<0.001). The intraobserver variability was 29% for investigator 1 and 8% for investigator 2. Mean IOP values of the two investigators taken with the TGDc-01 differed significantly (p<0.01) from each other by a mean of 2.6 mmHg.CONCLUSIONS: The new mobile tonometer TGDc-01 is better accepted by patients but IOP values are significantly lower compared to Goldmann tonometry and variability is high. Regarding glaucoma diagnostics it seems to be less suitable than Goldmann tonometry.     

Measurement of the intraocular pressure with the “transpalpebral tonometer” TGDc-01 in comparison with applanation tonometry

Background An irregular corneal surface compromises IOP measurement by Goldmann applanation tonometry. In such cases accurate measurement without corneal contact would be desirable. The new eyelid tonometer TGDc-01 measures IOP without corneal contact through the eyelid. The aim of the study was to evaluate the accuracy of the eyelid tonometer compared with Goldmann applanation tonometry (cornea thickness-corrected values) in subjects without corneal alterations.Methods IOP was measured in 199 eyes of 103 subjects without corneal alterations by means of two different methods. Measurements with the transpalpebral tonometer TGDc-01 and the Goldmann applanation tonometer were performed within 5 min in random order.Results The mean difference between lid tonometry and Goldmann applanation tonometry was 0.71 mmHg, SD ±2.467 mmHg. In the reliability analysis the intraclass correlation coefficient was 0.8620. Compared with Goldmann applanation tonometry 66.4% of the IOP readings measured by lid tonometry were in an interval of ±2 mmHg, 81.0% in an interval of ±3 mmHg. The maximum of deviation was –6 mmHg and +6 mmHg, respectively. The Bland and Altman plots are shown.Conclusions Lid tonometry correlates sufficiently with Goldmann applanation tonometry, but in more than 10% of the measurements the IOP readings differed by more than 3 mmHg. The eyelid tonometer may be helpful as a screening tool when Goldmann applanation tonometry is not applicable.     

Telemedicine-friendly, portable tonometers: an evaluation for intraocular pressure screening

PURPOSE: To evaluate the intraocular pressure (IOP) readings from two portable, telemedicine-friendly tonometers for suitability in glaucoma screening. METHODS: 213 eyes of 107 consenting patients attending an eye clinic were tested with an I-care tonometer and a Pulsair-Easy Eye puff-air tonometer. Gold standard IOP was measured with a Goldmann applanation tonometer (GAT). Effect of central corneal thickness, anterior chamber depth and refractive errors on IOP measurements were also analysed. RESULTS: The mean difference of IOP by GAT and both the portable tonometers was +/- 2.2 mmHg. The analysis indicates minimal difference between IOP readings of both the portable tonometers. The mean difference between two consecutive readings by I-care was 0.01 mmHg. Using 21 mmHg as a threshold for suspected glaucoma, both the portable digital tonometers reported a sensitivity of 38% and specificity of >95%. In the subjects studied, central corneal thickness had statistically significant influence on IOP measurements while refractive errors and anterior chamber depth had no significant influence on IOP measurements with any tonometry. CONCLUSION: The IOP readings by both portable tonometers are comparable and were within clinically acceptable range from GAT. These portable tonometers are useful tools for IOP screening.     

Evaluation of the new Ocuton S tonometer

PURPOSE: To evaluate the intra- and interobserver variability of the Ocuton S tonometer, its correlation with Goldmann tonometry, the reliability of self-tonometry and the safety of the instrument. METHODS: Thirty-five healthy subjects and 45 patients with primary open-angle glaucoma (POAG), aged from 38 to 80 years (mean age: 64.6 +/- 12.2 years), underwent tonometry with the Ocuton S tonometer in one eye chosen at random. The intra- and interobserver variability between two operators (kappa coefficient), the Ocuton S/Goldmann correlation and the reliability of self-tonometry were evaluated by performing two tonometries on each patient in subgroups. Each tonometry was considered as the mean of three consecutive measurements. Central ultrasonic pachymetry, keratometry and corneal biomicroscopy were also evaluated. RESULTS: The intra- and interobserver variability ranged from 0.38 to 0.66. The difference between the means of intraocular pressure (IOP) with the Ocuton S (24.4 +/- 4.7 mmHg) and the Goldmann tonometer (18.1 +/- 4.7 mmHg) was statistically significant (p < 0.0001). Linear regression analysis revealed a good Ocuton S/Goldmann correspondence (r = 0.88, p = 0.0001). However, IOP values detected with the Ocuton were consistently overestimated, compared to those detected with the Goldmann tonometer. The correlation between corneal thickness and IOP was statistically significant both for the Goldmann (r = 0.510, p = 0.021) and for the Ocuton S tonometer (r = 0.520, p = 0.019). No correlation was found between keratometry and IOP. The mean measurement obtained by self-tonometry (21.9 +/- 3.6 mmHg) showed no statistically significant difference when compared to the mean measurement obtained by an expert operator (21.3 +/- 3.4 mmHg). CONCLUSION: The Ocuton S tonometer is a safe instrument that can be used easily by the patient. However, in comparison to the Goldmann tonometer, it overestimates IOP and requires further technical and methodological refinements in order to ensure greater reliability.     

Ocuton-S self tonometry vs. Goldmann tonometry; a diurnal comparison study

PURPOSE: To compare 24-hour diurnal intraocular pressure (IOP) measurements obtained using the Ocuton-S applanation self tonometer and the Goldmann tonometer. METHODS: 24-hour diurnal IOP curves were obtained on 14 eyes of 7 trained patients suffering from medically controlled primary open angle glaucoma. IOP was measured every third hour starting at 9 a.m. with a calibrated Goldmann tonometer; one week later, a similar set of measurements was obtained with Ocuton-S self tonometry by the patients. One week later still, ultrasound corneal pachymetry was performed at the same hours. RESULTS: Overall IOP (24-hour mean) did not differ significantly between the different measuring techniques (ANOVA, p = 0.74), but the IOP differed in a statistically significant manner around the clock (ANOVA, p = 0.00006). The mean Goldmann tonometric readings were up to 2.8 mmHg lower than the Ocuton-S values during the daytime (9 a.m. to 9 p.m.), however, during the night (12 midnight to 6 a.m.) mean IOP measured with Goldmann tonometry was 2.2 to 3.3 mmHg higher than the corresponding average of the self tonometry readings. There was a statistically significant interaction between the type of tonometry and the time of the measurement (p = 0.0007). Central corneal thickness (CCT) showed a significant change during the 24-hour period (p = 0.000001). CONCLUSION: IOP shows a different diurnal curve when measured with the Goldmann tonometer and with the Ocuton-S applanation self tonometer. The instruments' readings might be influenced in different ways by the diurnal changes of the corneal thickness. Since Ocuton-S self tonometry underestimates the IOP in the early morning period, a careful evaluation is necessary when nocturnal and early morning IOP elevation is investigated with this technique.     

Comparison of the ICare® rebound tonometer with the Goldmann tonometer in a normal population

The aim of this study was to evaluate the accuracy of measurement of intraocular pressure (IOP) using a new induction/impact rebound tonometer (ICare) in comparison with the Goldmann applanation tonometer (AT). The left eyes of 46 university students were assessed with the two tonometers, with induction tonometry being performed first. The ICare was handled by an optometrist and the Goldmann tonometer by an ophthalmologist. In this study, statistically significant differences were found when comparing the ICare rebound tonometer with applanation tonometry (AT) (p < 0.05). The mean difference between the two tonometers was 1.34 +/- 2.03 mmHg (mean +/- S.D.) and the 95% limits of agreement were +/-3.98 mmHg. A frequency distribution of the differences demonstrated that in more than 80% of cases the IOP readings differed by <3 mmHg between the ICare and the AT. In the present population the ICare overestimates the IOP value by 1.34 mmHg on average when compared with Goldmann tonometer. Nevertheless, the ICare tonometer may be helpful as a screening tool when Goldmann applanation tonometry is not applicable or not recommended, as it is able to estimate IOP within a range of +/-3.00 mmHg in more than 80% of the population.     

Intraocular pressure measurement in mice: a comparison between Goldmann and rebound tonometry

PURPOSE: The development of mouse models of glaucoma requires methods to accurately measure the intraocular pressure (IOP) in this species. The aim of this study was to compare the accuracy of IOP measurements in mice between modified Goldmann and rebound tonometers. METHODS: IOP was measured either with a modified Goldmann or a rebound tonometer while simultaneously measuring the IOP using invasive manometry in enucleated eyes and in vivo. The level of IOP was controlled hydrostatically. The agreement and correlation between the IOP determined by invasive manometry and by either noninvasive method was evaluated. In addition, the IOP was determined by both noninvasive methods in a cohort of mice with laser-induced ocular hypertension (OHT), and the agreement and correlation between the two tonometry methods were evaluated. RESULTS: Measured IOP by either noninvasive tonometer correlated well with those recorded simultaneously by invasive manometry (r=0.98 for rebound and r=0.94 for Goldmann). In mice with OHT, the IOP correlation between rebound and modified Goldmann was moderate (r=0.71); the IOP measured by modified Goldmann tonometry was consistently higher than that by rebound by approximately 5 mmHg. However, the relative per cent increases in IOP were similar between the two methods. CONCLUSION: Both noninvasive methods of IOP measurements in mice are suitable to detect changes in IOP although rebound tonometry correlated better with the invasive manometry readings. The results suggest that the relative, rather than absolute, IOP offers a more reliable means of correlating findings from studies using different tonometers.     

A clinical evaluation of XPERTtm NCTtm (Reichert) for glaucoma screening by optometrists

XPERT^tm NCT^tm advanced logic pneumotonometer (Reichert) was studied for its reliability and use in glaucoma screening. The evaluated 2400 NCT measurements on 300 eyes were compared to the results of Goldmann applanation tonometry (GAT) from the same eyes. Repeated NCT tonometry had no significant effect on IOP. Local anesthesia reduced mean NCT-GAT difference and standard deviation significantly (p < 0.05), i.e. feeling due to the diminished air pulse force provided by the instrument had still considerable influence on IOP. NCT-GAT regression was significant (p < 0.01). Mean IOP readings provided by NCT were four mmHg higher than GAT values. Although accuracy was not satisfactory for exact measuring, it was satisfactory for screening. The results suggested that four mmHg less than the mean IOP value seen on the display is acceptable for screening when the difference between the minimal and maximal individual readings on the display is less than 2SD i.e. six mmHg. In the case of a greater difference, the maximal value is to be replaced, as NCT tends to read higher values than GAT.Abbreviations GAT Goldmann applanation tonometer - NCT XPERT NCT tonometer - IOP in-traocular pressure     

Three portable tonometers, the TGDc-01, the ICARE and the Tonopen XL, compared with each other and with Goldmann applanation tonometry*.

Three portable tonometers, the TGDc-01, the ICARE and the Tonopen XL, were compared with each other and to Goldmann applanation tonometry in a large group of healthy subjects and patients with ocular hypertension or glaucoma (n = 103). Measurements performed with the ICARE and the Tonopen XL were in good agreement with that of the Goldmann tonometer. Intraocular pressure (IOP) values measured with the TGDc-01 were significantly lower and showed more variability. The 95% limits of agreement (portable tonometer - Goldmann) were -17 to +10 mmHg for the TGDc-01, -6 to +7 mmHg for the ICARE and -6 to +8 mmHg for the Tonopen. Corneal thickness could not explain the differences between an IOP measured with the portable tonometers and an IOP measured with the Goldmann tonometer. Patient comfort was slightly higher for ICARE when compared with the Tonopen.     

New-generation portable tonometers: comparison of the Keta and Goldmann tonometers

The Keta Smart-001 is a recently introduced portable battery-operated tonometer with a digital readout. To determine the reliability of the Keta tonometer, intraocular pressure (IOP) measurements were taken in a masked fashion with the Keta tonometer and the Goldmann tonometer in both eyes of 60 patients (20 with and 40 without glaucoma) recruited from general ophthalmology and glaucoma clinics. The results were analysed with an F-test analysis of variance. The Keta tonometer significantly underread the IOP and was totally unreliable in patients with glaucoma. Our results indicate that Keta tonometry should not be used for the screening and management of glaucoma.     

Evaluierung der Reboundtonometrie (ICare) im Vergleich zum TonopenXL und dem Goldmann-Applanationstonometer

BACKGROUND: Goldmann applanation tonometry and dynamic contour tonometry (PASCAL) are two well established slit lamp mounted tonometric methods. Intraocular pressure measurement in bedridden patients and children is often only possible using hand held tonometers (TonoPenXL, Perkins tonometer, Draeger tonometer). This study was performed to evaluate the hand held ICare tonometer, which is based on the rebound method. METHODS: A total of 102 eyes were examined by two highly experienced ophthalmologists for: 1) ophthalmological status, 2) central corneal power (Zeiss IOL-Master), 3) central corneal thickness (Tomey ultrasound pachymetry, five successive measurements, SD<5%), 4) intraocular pressure (IOP) measurement with the Goldmann applantation tonometer (GAT) 1x, 5) TonoPenXL (1x), 6) ICare with three successive measurement series of 6 single measurements. RESULTS: The mean IOP(GAT) was 13.2+/-3.0 mmHg compared with the mean IOP(TonoPenXL) (13.4+/-3.1 mmHg) and with the IOP(ICare) (mean value of first measurement series: 13.4+/-3.1 mmHg). The series of measurements with the ICare showed a tonography effect (decrease of IOP from 14.6 mmHg at the first measurement and 14.2 mmHg at the second to 14.0 at the third measurement). The ICare-measurements were highly reliable (Cronbach's alpha=0.974) and showed a good correlation between the measurement series (r=0.592-0.642; p<0.001). There was a great intra-individual variability of up to 17 mmHg between the GAT, TonoPenXL and ICare methods. CONCLUSIONS: The ICare tonometer is easy to handle and high reliability. The data are comparable with those from the Goldmann tonometer. A tonography effect of 0.6 mmHg in the successive measurement series was found.     

Prospective comparison of the new indentation tonometer TGdC-01, the non-contact tonometer PT100 and the conventional Goldmann applanation tonometer

BACKGROUND: This study aimed to compare the results of newer tonometric techniques with standard tonometry for the examples of the Goldmann applanation tonometry (GAT), the indentation tonometer "TGDc-01" and the non-contact tonometer "PT 100". PATIENTS: The study was conducted on a total of 52 healthy subjects. The IOP was measured in each subject on both eyes with all three methods. There were 27 males (51.9 %), 25 females (48.1 %) with an average age of 28.5 years, with a minimum of 13 and a maximum of 79 years. RESULTS: There was no statistically significant difference between the non-contact and the Goldmann applanation tonometry. The measurements were 0.4 mmHg lower, no difference for the left or right side was seen. For IOP higher than 15 mmHg - 0.88 mmHg lower and for IOP lower 15 mmHg - 0.15 mmHg. The results for the "TGDc01" were 0.82 mmHg lower than GAT, the standard deviation was a little higher with 2.9 mmHg compared to 2.67 mmHg for GAT. For IOP higher than 15 mmHg they rose up to - 2.28 mmHg, for IOP lower than 15 mmHg the results for "TGDc-01" were only - 0.2 mmHg lower. There was also an effect with respect to the side, on the right eye the difference was significant with 3.03 mmHg (p = 0.006), in contrast to the left eye with 2.69 mmHg (p = 0.235). For "TGDc01" the standard deviation was higher with 2.9 mmHg compared to 2.6 mmHg for "PT 100". CONCLUSIONS: The non-contact tonometer showed no clinical relevant difference compared with GAT for measuring IOP. The indentation tonometer showed differences for precision, for higher tension IOP the measurement was lower compared with GAT. There was also a significant side difference using the "TGDc-01".     

探讨24h眼压检查对青光眼诊断的意义

目的:评价24h眼压测量在青光眼患者诊断中的意义。方法:选择青光眼疑似患者51例51眼,使用Goldmann眼压计进行24h眼压测量。结果:所有患者中,21眼(41.2%)的眼压在正常范围内且昼夜眼压波动小于6mmHg(1mmHg=0.133kPa),30眼(58.8%)出现昼夜眼压波动过大或峰值眼压高于21mmHg。其中7例出现仅有夜间高眼压且最高者达54mmHg,白天自然缓解到正常范围。24h眼压平均值及高峰值与门诊眼压记录相比,差异均具有统计学意义(P<0.01)。结论:24h眼压测量与门诊检查眼压相比,能更好地发现高眼压和昼夜眼压波动异常患者。     

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.     

Tono-Pen,a new tonometer

The Tono-Pen is a miniaturized Mackay-Marg tonometer with electronic signal analysis and digital pressure display. In study 1, we compared the Tono-Pen with Goldmann tonometry in 108 healthy human subjects (216 eyes). In 33 of these subjects, the IOP was changed in a range between 0 and 50 mmHg by a scleral suction-cup system. In study 2, the Tono-Pen was compared with a Statham membrane manometer in 6 humans (12 eyes), 3–6 h after death. The IOP was changed in a range between 0 and 60 mmHg by an infusion system.—Results: Related to the Goldmann tonometer, the Tono-Pen gave a small overestimation of IOP below 16 mmHg (maximum deviation 1.5 mmHg at 0 mmHg Goldmann reading). Above 16 mmHg, however, the Tono-Pen increasingly underestimated the IOP determined by Goldmann tonometry (maximum deviation 8 mmHg at 50 mmHg Goldmann reading). Related to the manometer, the Tono-Pen gave a small overestimation of IOP below 17 mmHg and small underestimation above 17 mmHg (maximum deviation 2.5 mmHg at manometer readings of 0 and 60 mmHg, respectively).— Conclusions: Throughout the entire clinically relevant IOP range, an acceptable relationship between Tono-Pen and manometer readings was found in human cadaver eyes, whereas the relationship between Tono-Pen and Goldmann tonometric readings in the clinical study was found to be acceptable only in the low and physiological IOP range. The considerable deviation from the Goldmann readings in the high IOP range requires further modifications of The Tono-Pen.     

Pneumotonometry using sterile single-use tonometer covers.

Current methods for cleaning pneumotonometer tips include soaking the removable tip in various chemical agents. Disadvantages of this technique include the potential for incomplete disinfection, corneal contact with cleaning solutions, tip damage or loss, and soaking time. The authors studied the use of an available, disposable latex cover placed over the pneumotonometer tip for measuring intraocular pressure (IOP) in 46 eyes with normal corneas from a glaucoma screening clinic and 141 eyes with normal and abnormal corneas from a cornea and external disease clinic. The mean absolute IOP difference comparing with and without the tonometer cover was 1.6 mmHg for the glaucoma screening patients and 1.8 mmHg for the cornea clinic patients. A tonographic-like effect due to repeated tonometry also was shown. An additional study measuring a series of known IOP values in a cadaver eye showed no significant difference between uncovered and covered readings. These data suggest that placement of a disposable, latex cover over the pneumotonometer tip enables accurate IOP measurements and is a sanitary and convenient alternative method to repeated chemical disinfection.     

The effect of repeated applanation on subsequent IOP measurements

Background: In studies aimed at assessing the accuracy and repeatability of non‐contact tonometers, the order in which these tonometers and the Goldmann tonometer are used is usually randomised despite studies in the literature that demonstrate an ocular massage effect that occurs post‐applanation but not after non‐contact tonometry. The purpose of this study was to investigate the effect of repeated corneal applanation on subsequent assessments of IOP. Methods: Data were obtained from 65 left eyes of 65 young, oculovisual normals. Three sets of IOP measurements were obtained, one set with the Goldmann applanation tonometer and two with the Topcon CT80 non‐contact tonometer (one set each before and after applanation with the Goldmann tonometer), in each one of two separate measurement sessions, one week apart. Results: The average (and SD) IOP measured with the Goldmann tonometer in the first session (14.8 ± 2.9 mmHg) did not vary significantly from the IOP measured with the non‐contact tonometer (pre‐applanation) in both sessions or with the average Goldmann IOP in the second session. The bias (mean difference ± SD) between methods was 0.3 ± 1.4 mmHg and 0.4 ± 1.4 mmHg, respectively, for the first and second sessions, with the CT80 (pre‐applanation) recording the higher IOP in both sessions. The within‐session repeatability coefficients were ±2.3 mmHg, ±2.6 mmHg, ±2.1 mmHg and ±2.0 mmHg for the CT80 (pre‐applanation) in the first and second sessions, and the Goldmann tonometer in the first and second sessions, respectively. Test‐retest repeatability coefficients were ±2.8 mmHg and ±2.5 mmHg for the CT80 (pre‐applanation) and the Goldmann tonometer respectively. Post‐applanation with the Goldmann tonometer, there was a statistically significant (p < 0.05) reduction (1.5 ± 1.2 mmHg in session 1) in the IOP measured with the non‐contact tonometer in both sessions. Conclusion: These results suggest that repeated corneal applanation leads to a statistically significant reduction in IOP on subsequent measurements.     

新型眼压计原理及其在临床中的应用

眼压测量是目前对青光眼进行疗效观察及随访的主要手段之一,眼压计是临床工作中测量眼压的重要工具,修氏眼压计和Goldmann 压平眼压计长期以来为国内外临床医生所广泛应用,近十年来,又出现了一些新型的眼压计,如动态轮廓眼压计（DCT）、I Care回弹眼压计、Tono-Pen眼压计、Diaton眼压计和Proview压眼闪光眼压计等。其原理各异,临床应用价值也众说纷纭。DCT与Goldmann 压平眼压计（GAT）有较好的相关性,且测量值不受角膜性状的影响,但其对于配合差者有较大误差。I Care回弹眼压计、Tono-Pen眼压计、Diaton眼压计和Proview压眼闪光眼压计均为便携式眼压计,测量时不需使用麻醉药,便于青光眼的筛查,但其临床应用较少,测量的准确性仍需进一步研究。（眼科,2012,21： 136-140）