Comparison of dynamic contour tonometry and Goldmann applanation tonometry in relation to central corneal thickness in primary congenital glaucoma

Background

To compare intraocular pressure (IOP) measurements obtained with dynamic contour tonometer (DCT) and Goldmann applanation tonometer (GAT), and to investigate their relationship to central corneal thickness (CCT) in primary congenital glaucoma (PCG) eyes.

Methods

Thirty-one eyes of 31 PCG patients (25.7?±?7.2 years old) were examined. PCG was defined as elevated IOP, enlarged corneal diameter (buphthalmos), Haab’s striae and abnormal findings at gonioscopy. The mean of three measurements of GAT, DCT (quality scores 1 and 2), and CCT were obtained and assessed for agreement by means of Bland–Altman plot and for Spearman correlation test.

Results

Mean CCT was 534?±?72.3 μm (range: 430 to 610 μm). Mean IOP measurements were 15.1?±?4.2 mmHg (range: 5.5 to 22.7 mmHg) for DCT and 14.5?±?5.6 mmHg (range: 7.0 to 34.0 mmHg) for GAT (P?=?0.244). Spearman correlation tests showed that IOP difference (DCT ? GAT) was not correlated with CCT (r ²?=?0.023, P?=?0.417). IOP measurements by DCT were weakly but statistically correlated with those obtained with GAT (r²?=?0.213, P?=?0.0089). Bland–Altman analysis revealed poor agreement between DCT and GAT readings, considering the 95 % confidence intervals of ±10.45 mmHg.

Conclusions

The differences between DCT and GAT readings were not influenced by CCT in this series of patients. Considering the weak correlation and the poor agreement observed between GAT and DCT measurements and that they both may be affected by corneal biomechanical changes, these methods should not be used interchangeably, and may possibly give no meaningful IOP values in PCG patients.     

Comparative measurement of intraocular pressure by Icare tonometry and Airpuff tonometry in healthy subjects and patients wearing therapeutic soft contact lenses

Background

The aim of the present study was to compare the measurement of intraocular pressure (IOP) through a therapeutic soft contact lens with the “native” measurement. We additionally investigate whether a rebound tonometer (RT) or non-contact tonometer (NCT) is more suitable to measure IOP through a bandage contact lens.

Methods

The IOP was determined using each of the two methods, three times successively with (lens measurement) and without (native measurement) a soft contact lens. The Icare tonometer (Icare® TA01i, Icare Finland Oy, 23 subjects) and the Airpuff tonometer (Nidek NT 53OP, Nidek CO., LTD, Hiroishi Gamagori, Aichi, Japan, 16 subjects) were used. We compared the mean values (validity parameter) and standard deviation (precision parameter) of the three individual measurements in each case using the paired t-test. In addition, we conducted a power analysis to estimate the maximum error in the measurement caused by the contact lens (power level set to 0.8).

Results

With the Airpuff tonometer we detected no statistically significant between the lens and the native measurement (15.6?±?2.6 vs. 15.3?±?2.6 mmHg; p?=?0.42). The power analysis revealed that the maximum error caused by the contact lens was 1.2 mmHg. The Icare tonometry, however, trended toward higher values in the contact lens measurements (17.5?±?4.3 vs. 16.4?±?3.5 mmHg in the native measurements; p?=?0.05). Interestingly, this difference exhibited a statistically significant correlation with the corneal thickness (0.03 mmHg per μm corneal thickness; p?=?0.04).

Conclusion

The use of NCT and RT for IOP measurement over a soft contact lens is feasible. The accuracy appears to be sufficient for the most common clinical applications.     

Effectiveness of the ICare rebound tonometer in patients with overestimated intraocular pressure due to tight orbit syndrome

Purpose

To evaluate the effectiveness of the ICare rebound tonometer in patients with overestimated intraocular pressure (IOP) due to tight orbit syndrome and to identify factors affecting the development of tight orbit syndrome in glaucoma patients.

Methods

We investigated 84 eyes in 84 glaucoma patients, of which 14 eyes were classified in the tight orbit syndrome group and 70 eyes in the control group. IOP was measured using the ICare tonometer and the Goldmann applanation tonometer (GAT). The demographic data, medical histories, ocular histories, and detailed ocular drug histories of the two groups were compared to identify factors contributing to the development of tight orbit syndrome.

Results

In the tight orbit syndrome group, the ICare tonometer significantly underestimated the IOP by approximately 8.6 mmHg compared with the GAT. In the control group, the IOP readings of the GAT and the ICare tonometer did not differ significantly. Bland–Altman analysis showed that the mean difference between measurements taken using the GAT and those taken using the ICare tonometer was 2.5 ± 6.3 mmHg. The difference between the GAT and ICare tonometer measurements was greater in the tight orbit syndrome group (8.6 ± 5.3 mmHg) than in the control group (1.3 ± 2.7 mmHg). Multivariate regression analysis revealed that only the use of prostaglandin analogs (PGAs) was associated with the development of tight orbit syndrome.

Conclusions

The ICare tonometer is a suitable alternative device for use in patients with tight orbit syndrome in whom the IOP may be overestimated with the GAT. The prolonged use of PGAs is significantly associated with the development of tight orbit syndrome.     

Ab interno gel implant in patients with primary open angle glaucoma and pseudoexfoliation glaucoma

Purpose

To compare efficacy and safety results of an ab interno gel implant in patients with pseudoexfoliation glaucoma (PXG) and primary open angle glaucoma (POAG).

Methods

Retrospective analysis of the medical records of 110 consecutive eyes with open angle glaucoma who had received a XEN45 gel implant between March 2014 and June 2015. Intraocular pressure course, number of glaucoma medications, the need for additional intervention (including needling) and complications were evaluated until 12?months postoperatively.

Results

Data of 67 eyes with POAG and 43 eyes with PXG were analyzed. At 12?months postoperatively, the mean IOP had significantly decreased by 54.0% from preoperatively 31.85?±?8.5?mmHg to 13.99?±?2.6?mmHg in the POAG group, (p?=?0.000; Wilcoxon test), and by 55.2% from 31.63?±?9.0?mmHg to 13.28?±?3.1?mmHg in the PXG group (p?=?0.000; Wilcoxon test). The mean number of anti-glaucoma medications had significantly decreased from 3.25?±?0.8 at baseline to 0.3?±?0.7 medications at 12?months postoperatively in POAG eyes (p?=?0.000; Wilcoxon test), and from 3.05?±?1.0 to 0.3?±?0.6 medications in PXG eyes (p?=?0.000; Wilcoxon test). Hypotony (IOP?≤?6?mmHg) was observed in 2 POAG eyes (3.0%) and in 5 PXG eyes (11.7%) at 1?month but normalized in all eyes at 12?months postoperatively. Severe complications were not observed. No statistically significant differences were found between PXG eyes and POAG eyes.

Conclusion

Our data indicate that the XEN45 gel implant provides significant and comparable reduction in IOP and anti-glaucoma medication during the one-year follow-up period in POAG as well as PXG eyes. This suggests that it may be a noteworthy alternative to traditional filtering procedures in patients with POAG and PXG respectively.

     

Comparison of the new rebound tonometer with Goldmann applanation tonometer in a clinical setting

Purpose: To evaluate the clinical usefulness of a new rebound tonometer, Icare^® PRO (Icare PRO), by comparison with Goldmann applanation tonometry (GAT) in a study on patients with glaucoma. Methods: One hundred and seventy‐two eyes of 86 subjects were enrolled in this study. All of the subjects were examined with an autorefractometer, Icare PRO, slit‐lamp biomicroscope, GAT, ultrasound A‐scan and pachymeter. Three intraocular pressure (IOP) measurements were obtained by Icare PRO and GAT. The intraobserver reliabilities were established by calculating the intraclass correlation coefficients. The Bland–Altman plot was used to compare the Icare PRO and GAT. Results: There was a good correlation between the IOP measurement by GAT and that by Icare PRO (r = 0.6995, p < 0.001). The intraclass correlation coefficients of Icare PRO and GAT were 0.778 and 0.955, respectively. The IOP differences between Icare PRO and GAT (mean: 1.92 mmHg; SD: 3.29 mmHg; 95% limit of agreement: ?4.52 to 8.37 mmHg) did not vary over the wide range of central corneal thickness (p = 0.498), age (p = 0.248), axial length (p = 0.277) or spherical equivalent (p = 0.075). Conclusions: Although IOP with Icare PRO was higher than that with GAT, especially at lower GAT IOP value, Icare PRO was found to be a reliable method and showed a good correlation with GAT. The IOP difference between Icare PRO and GAT was not affected by the central corneal thickness, age, axial length or spherical equivalent. Icare PRO can be expected not only to be a good screening tool but also to be a good substitute for GAT.     

可疑青光眼患者清晨起床前后的体位变化和日常活动对眼压的影响

目的：观察可疑青光眼患者清晨起床前后的体位变化和日常活动对眼压的影响。 方法：使用Icare回弹式眼压计对51例100眼可疑青光眼患者进行清晨起床前后的卧、坐位和日常活动前后的眼压测量,对比分析卧、坐位眼压和日常活动前后的眼压测量结果。 结果：起床前卧、坐位测量的眼压均值分别为19.14±5.51和17.12±4.53mmHg,两者差别显著。清晨日常活动前后测量的眼压均值分别为17.12±4.53和14.44±3.90mmHg,两者有显著差别。 结论：起床前后的体位变化和日常活动可以导致显著的眼压变化。     

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。     

Can we measure the intraocular pressure when the eyeball is against the pillow in the lateral decubitus position?

Purpose: To evaluate the amount of intraocular pressure (IOP) change in the eye against the pillow in the lateral decubitus position (LDP). Methods: Thirty eyes from 15 healthy volunteers (12 men and three women) aged 29 ± 3 (range 25–37) years participated in this study. Using the rebound tonometer (Icare PRO, Icare Finland Oy, Helsinki, Finland), the IOP of both eyes was checked in sitting, supine, right and left LDPs. In the LDP, the additional IOP measurements were taken with the lower eyeball against the latex pillow. Results: Baseline IOP in the sitting position was 12.7 ± 1.9 mmHg in the right eye and 12.8 ± 2.2 mmHg in the left eye. Ten minutes after shifting from the sitting to the supine position, IOP increased significantly (right eye: +1.4 ± 1.4 mmHg, p = 0.006; left eye: +1.8 ± 1.5 mmHg, p = 0.001). Changing from the supine to the right and left LDP increased significantly the IOP of dependent eye (right eye: +2.3 ± 1.8 mmHg, p = 0.001; left eye: +1.5 ± 1.8 mmHg, p = 0.011). When the dependent eye was compressed against the pillow in the LDP, the IOP of the dependent eyes increased significantly after 10 min (right eye in the right LDP: +4.1 ± 4.9 mmHg, p = 0.011; left eye in the left LDP: +3.4 ± 3.7 mmHg, p = 0.006). Conclusion: The IOP was significantly elevated when the eyeball was against the pillow in the LDP.     

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.

     

A comparison between Goldmann applanation tonometry and dynamic contour tonometry after photorefractive keratectomy

Background

The intraocular pressure (IOP) could be measured by both Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT). Although these two methods have been discussed widely after laser-assisted sub-epithelial keratectomy (LASIK), there is little data in the cases undergoing photorefractive keratectomy (PRK). We aimed to compare the changes of IOP measurements obtained by GAT and DCT after PRK for myopia/myopic astigmatism.

Methods

This prospective study enrolled 77 candidates (154 eyes) for PRK to correct myopia or myopic astigmatism and 30 matched patients (30 eyes) with myopia or myopic astigmatism who served as controls. Changes of the IOP measurements (ΔIOP) obtained by GAT and DCT before and at 6 months after PRK in the operated eyes, and at baseline and 6 months later in the controls, were documented. Changes of the central corneal thickness (ΔCCT) were determined in the same fashion.

Results

The mean IOP readings obtained by DCT were comparable before and at 6 months after procedure (18.34 ± 3.03 mmHg and 17.87 ± 2.61 mmHg respectively, p?=?0.41); whereas the mean IOP reading obtained by GAT decreased significantly 6 months postoperatively (17.92 ± 3.63 mmHg and 16.25 ± 2.66 mmHg, p?<?0.001). A significant correlation was present between the ΔIOP obtained by GAT and ΔCCT (r?=?0.61, p?<?0.001). Similar correlation was not significant between the DCT-obtained ΔIOP and the ΔCCT (r?=?0.07, p?=?0.44). The mean ΔIOP obtained by GAT was significantly higher in the operated eyes than in the controls (?1.54?±?1.45 vs 0.07?±?0.44 mmHg, p?=?0.02). The mean DCT-obtained ΔIOP was just marginally insignificant between the operated and nonoperated eyes (?0.63?±?0.59 vs 0.02?±?0.38 mmHg respectively; p?=?0.09).

Conclusions

The authors recommend DCT after PRK in the cases with myopia or myopic astigmatism     

Effects of trabeculectomy on posture-induced intraocular pressure changes over time

Introduction

To determine whether trabeculectomy affects postural-induced changes in intraocular pressure (IOP), and whether it is maintained.

Methods

Thirty-six eyes of 36 patients with open-angle glaucoma who were scheduled for their initial trabeculectomy with adjunctive mitomycin C were prospectively examined. The IOP was measured in the sitting and the lateral decubitus position with an ICare rebound tonometer before, and 1, 3, and 12?months after trabeculectomy.

Results

Twenty-nine eyes of 29 patients completed this study. The mean baseline IOP measured with the ICare tonometer was 17.4?±?4.9?mmHg in the sitting position and 21.3?±?5.6?mmHg in the lateral decubitus position (p?p?p?=?0.004 respectively). This decrease in the degree of posture-dependent IOP change was maintained at +1.7?±?2.2?mmHg at 1 year postoperatively (p?Conclusions Our results indicate that trabeculectomy not only reduces the IOP but also reduces the degree of posture-induced changes in the IOP. Our findings also speculate that measuring the postural IOP changes after trabeculectomy might provide a clue on the functioning of a filtering bleb.     

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.     

Switching efficacy on intraocular pressure from latanoprost to bimatoprost in eyes with open angle glaucoma: implication to the changes of central corneal thickness

Purpose

Intraocular pressure (IOP)-lowering effects of 0.03 % bimatoprost in eyes with open angle glaucoma (OAG) was compared with that of 0.005 % latanoprost.

Methods

Thirty-one patients with OAG who had received three kinds of ocular hypotensive agents (latanoprost, beta-blocker, and topical carbonic anhydrase inhibitor) were included in this study. In these patients, bimatoprost was administered for 8 weeks after switching from latanoprost. The IOP was measured with a goldmann applanation tonometer (GAT) at the baseline, and Weeks 2, 4 and 8 after switching the treatment. The IOP at the baseline and at the end of treatment period was measured at 10:00, 12:00, and 16:00. The central corneal thickness (CCT) was measured at each visit using an ultrasonic pachymeter.

Results

At the baseline, the mean IOP was 18.8 ± 1.4 mmHg, and the CCT was 530.7 ± 29.5 μm. At Week 8 after switching treatment, bimatoprost significantly reduced the IOP by 2.0 ± 1.6 mmHg from the baseline (p < 0.001). The CCT tended to be reduced (p = 0.009; Repeated ANOVA) and Bonferroni test indicated a statistically significant decrease of the CCT at Week 8 in comparison with that at the baseline (p = 0.013).

Conclusions

Bimatoprost has an IOP-lowering effect superior to that of latanoprost in glaucoma patients after switching from latanoprost. The use of bimatoprost can decrease the CCT for a relatively short period in a linear regression fashion.     

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。     

Evaluierung der dynamischen Konturtonometrie bei Keratokonus

Purpose

The gold standard for measuring intraocular pressure (IOP) until now has been Goldmann applanation tonometry (GAT), which depends on the central corneal thickness (CCT) and curvature. In patients with keratoconus who have an abnormal corneal geometry and thickness, measurement of pressure with GAT is often difficult and not very reproducible. We compared the impact of the central corneal thickness (CCT) on the IOP measured with dynamic contour tonometry (DCT), a digital method which is adapted to the corneal geometry, and GAT in patients with keratoconus.

Methods

IOP was measured in 54 patients (38 men and 16 women, mean age of 36±9.9 years) with GAT and DCT in randomized order. All patients had a keratoconus which was assured by topography. In addition central corneal thickness (CCT) was measured with the Pentacam. For statistical analysis the Pearson correlation was calculated and a Bland-Altman diagram plotted.

Results

Mean corneal thickness was 486.2±45.5 μm. DCT measured the IOP at a mean value of 14.9±2.6 mmHg and GAT at 13.3±2.9 mmHg. With a mean difference of 1.6±2.4 mmHg DCT measured significantly higher than GAT (p≤0.05) Neither IOP measurements with GAT (r=?0.03; p>0.05) nor those with DCT (r=0.08; p>0.05) showed a significant correlation to central corneal thickness.

Conclusion

The example of keratoconus confirms that IOP measured by GAT is lower than if measured by DCT. Because both methods are independent of the CCT they are equally acceptable for IOP follow-up in eyes with keratoconus, which may result in progressive corneal thinning in the long term.     

疑似青光眼患者24h眼压变化规律

目的：分析疑似青光眼患者24h眼压的变化规律。

方法：收集疑似青光眼患者48例96眼,使用Accupen手持眼压计(24-3000)和NCT非接触眼压计(CT-80)测量24h眼压,自7：30开始,每2h测一次眼压,共12次,其中7：30～21：30测量坐位眼压,23：30～5：30测量坐位及卧位眼压。

结果：两种眼压计测量的传统体位下24h眼压峰值均出现在7：30,非接触眼压计测得的结果为22.05±3.608mmHg,手持式眼压计测得的结果为19.79±4.147mmHg。手持眼压计测得习惯性体位下眼内压峰值出现在5：30,平均21.64±4.814mmHg,且两种体位24h眼内压谷值均出现在21：30,谷值眼内压平均值为15.73±3.649mmHg。两种体位均呈夜间眼压逐渐升高,白天眼压逐渐下降的趋势。

结论：疑似青光眼患者眼内压峰值多出现在清晨,夜间卧位眼压值较坐位眼压值高。     

Intraocular pressure alterations after visual field testing

Purpose

To determine whether intraocular pressure (IOP) is significantly altered after visual field (VF) testing in eyes with open-angle glaucoma (OAG).

Methods

A prospective clinical trial of 106 OAG patients who had not had any previous surgical interventions. IOP was measured with a non-contact tonometer and refractive error with an auto refractometer. The measurements were made before and immediately after the VF test of the first eye (OD) and the second eye (OS).

Results

The baseline refractive error (spherical equivalent) was ?4.13 ± 3.61 diopters (D) OD and ?4.05 ± 3.63 D OS. The average VF testing time was 7.5 ± 1.4 min OU. The average baseline IOP was 12.8 ± 2.9 mmHg OD and 12.6 ± 2.8 mmHg OS. After the VF testing OD, the average IOP decreased significantly to 12.3 ± 2.6 mmHg (P = 0.001), but the IOP (12.5 ± 2.6 mmHg) OS was not significantly unchanged (P = 0.190). Following the VF testing OS, the IOP OD was 12.2 ± 2.6 mmHg (P = 0.252) and OS was 12.4 ± 2.7 mmHg (P = 0.487). An elevation of ≥2 mmHg in the IOP after the VF testing was found in 2.8 % of the right eyes and 0.9 % of the left eyes. The refractive error was not significantly changed after the VF testing. Multivariate analysis showed statistically significant correlations between the IOP decrease after the VF testing and the baseline IOP (P = 0.000) and the central corneal thickness (P = 0.034).

Conclusions

In the majority of eyes with OAG, VF testing did not lead to an increase in the IOP. The amount of IOP reduction after VF testing is significantly correlated with the baseline IOP and central corneal thickness.     

Influence of Selective Laser Trabeculoplasty (SLT) on combined clear cornea phacoemulsification and Trabectome outcomes

Background

In this retrospective comparative cohort outcome study, the influence of Selective Laser Trabeculoplasty (SLT) on combined clear cornea phacoemulsification and ab interno trabeculectomy (Trabectome) outcomes in Primary Open Angle Glaucoma (POAG), Pseudoexfoliation Glaucoma (PEX), and Pigmentary Glaucoma (PG) was examined.

Methods

Combined clear cornea phacoemulsification and Trabectome were performed in 27 consecutive patients with POAG, in 27 patients with PEX, and in 20 patients with PG. Each group was divided into two subgroups including patients without SLT treatment prior to surgery and patients who had insufficient response to 360° SLT treatment three months prior to surgery.

Results

In the SLT group, mean IOP at six months measured 13.33?±?2.08 mmHg with an average decrease of 30 % from preoperative IOP in the POAG group, 12.10?±?1.40 mmHg with an average decrease of 46 % in the PEX group, and 11.83?±?2.21 mmHg with an average decrease of 38 % in the PG group. In eyes without previous SLT, mean IOP sixt 6 months measured 11.00?±?1.73 mmHg with an average decrease of 38 % from preoperative IOP in the POAG group, 15.50?±?1.41 mmHg with an average decrease of 35 % in the PEX group, and 15.67?±?2.91 mmHg with an average decrease of 36 % in the PG group, respectively.

Conclusions

Prior SLT treatment seems not to negatively influence combined clear cornea phacoemulsification and Trabectome outcomes in glaucoma patients. However, SLT treatment may even have an additive effect on following combined Trabectome outcomes in patients with PEX and PG.     

Hornhautdickenabhängige Korrekturfaktoren bei der Goldmann-Applanationstonometrie

Background

For many years researchers have discussed which corneal parameters can influence the measurement of intraocular pressure (IOP). As a substantial parameter, the central corneal thickness (CCT) is assumed; however, different measuring methods – including Goldmann applanation tonometry (GAT), dynamic contour tonometry (DCT), and corneal compensated pressure measured with the ocular response analyzer (IOPcc) – may lead to a completely different dependence on corneal thickness.

Method

In a study approved by the ethics commission, the anterior chamber of 92 eyes of cataract patients and 85 eyes of glaucoma patients with very different CCT measurements was cannulized before surgery (cataract operation or trabeculectomy), and the IOP values were measured simultaneously with a pressure absorber and with GAT (Perkins tonometer) at different pressure values.

Results

The individual measurements exhibited an extraordinarily wide dispersion. In both groups, weak correlations of the difference between GAT and IOP values with the CCT were found (correction factors of 0.95 mmHg/100 µm CCT at pressure level 20 mmHg, 1.2 mmHg/100 µm CCT at pressure level 30 mmHg, and 1.7 mmHg/100 µm CCT at pressure level 40 mmHg).

Conclusions

Measurement of CCT is valuable for prognostic assessment of glaucoma, but not for correction factors for corneal thickness.     

非接触式和Goldmann压平眼压计测量结果的一致性分析

目的：在原发性开角型青光眼（ POAG ）中应用佳能TX-F非接触式眼压计（ NCT）和Goldmann压平眼压计（ GAT）测量眼压（ IOP）,并比较测量值。 方法：55例（55右眼）确诊为POAG的患者接受详细的眼科检查,光学相干断层扫描成像和自动视野检查。使用NCT1（一次喷气模式）, NCT3（三次喷气模式）和GAT测量眼压,每隔5分钟一次。 结果：55例（55右眼） POAG 患者平均年龄为64.1±8.1岁。比较NTC1,NTC3测量的眼压值（14.22±3.42,14.28±3.29mmHg）与GAT测量的眼压值（14.66±3.49mmHg）无统计学差异（ P=0.291）。使用Bland-Altman 方法比较NCT1-GAT, NCT3-GAT和NCT1-NCT3得出的95%一致性界限（IOA）分别为-4.9~＋4.4mmHg,-4.1~＋3.4mmHg和-3.4~＋3.3 mmHg。 结论：虽然NCT与GAT测量的眼压值相似,但偏大的IOA范围限制了NCT1,NCT3和GAT在POAG患者中的互换应用。