scholarly journals Intraocular Pressure Measurement Using Ocular Response Analyzer, Dynamic Contour Tonometer, and Scheimpflug Analyzer Corvis ST

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Lisa Ramm ◽  
Robert Herber ◽  
Eberhard Spoerl ◽  
Frederik Raiskup ◽  
Lutz E. Pillunat ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Healthy Subjects ◽  
Corneal Thickness ◽  
Applanation Tonometry ◽  
Ocular Response Analyzer ◽  
Corvis St ◽  
Dynamic Contour Tonometer ◽  
Iop Measurement ◽  
Good Agreement

Purpose. To compare intraocular pressure (IOP) measurements with Goldmann applanation tonometry (GAT), ocular response analyzer (ORA), dynamic contour tonometer (DCT), and Corvis ST (CST) in healthy subjects. Methods. In a prospective, observational study, IOP measurements with GAT (GAT-IOPc), ORA (IOPcc), DCT (DCT-IOP), and CST (bIOP) were performed and analyzed in 94 healthy subjects. Results. Mean age of the participants was 45.6 ± 17.2 years (range 18 to 81 years). Mean GAT-IOPc was 12.9 ± 2.4 mmHg, mean DCT-IOP was 16.1 ± 2.6 mmHg, and mean IOPcc was 15.6 ± 3.3 mmHg. DCT-IOP and IOPcc were significantly higher than GAT-IOPc (P<0.001). Mean bIOP was 13.5 ± 2.4 mmHg that was slightly higher but not significantly different from GAT-IOPc (P=0.146). Correlation analysis of IOP values and central corneal thickness (CCT) revealed a negative correlation between GAT-IOPc and CCT (r = −0.347; P=0.001). However, IOPcc, DCT-IOP, and bIOP showed no significant correlation to CCT. Only bIOP revealed a weak but significant age dependency (r = 0.321, P=0.002). Conclusion. All tonometry devices showed a good agreement of biomechanical corrected IOP values with GAT-IOPc. As no influence of CCT on IOPcc, DCT-IOP, and bIOP was detectable, the used correction algorithms appear to be appropriate in these tonometers in the clinical setting. The highest agreement was found between GAT-IOPc and bIOP. However, bIOP weakly correlated with participants’ age. Further studies are needed to elucidate the role of bIOP for IOP measurement.

Intraocular pressure measurements in diabetes mellitus

2019 ◽  
Vol 30 (6) ◽  
pp. 1432-1439 ◽  
Author(s):  
Lisa Ramm ◽  
Robert Herber ◽  
Eberhard Spoerl ◽  
Lutz E Pillunat ◽  
Naim Terai
Keyword(s):  
Diabetes Mellitus ◽  
Intraocular Pressure ◽  
Healthy Subjects ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Applanation Tonometry ◽  
Goldmann Applanation Tonometry ◽  
Ocular Response Analyzer ◽  
Pressure Measurements ◽  
Corvis St

Purpose: To investigate the impact of diabetes mellitus–induced changes on intraocular pressure measurements using Goldmann applanation tonometry, Ocular Response Analyzer, and Corvis ST. Methods: Measurements were done using Goldmann applanation tonometry, Ocular Response Analyzer, and Corvis ST in 69 diabetic patients. Biomechanical-corrected intraocular pressure values by Ocular Response Analyzer (IOPcc) and Corvis ST (bIOP) were used. In addition, biometry and tomography were performed and information on diabetes mellitus specific factors was collected. Results were compared to an age-matched group of 68 healthy subjects. Results: In diabetes mellitus, Goldmann applanation tonometry intraocular pressure (P = 0.193) and central corneal thickness (P = 0.184) were slightly increased. Also, IOPcc (P = 0.075) and bIOP (P = 0.542) showed no significant group difference. In both groups, IOPcc was higher than Goldmann applanation tonometry intraocular pressure (P = 0.002, P < 0.001), while bIOP was nearly equal to Goldmann applanation tonometry intraocular pressure (P = 0.795, P = 0.323). Central corneal thickness showed a tendency to higher values in poorly controlled than in controlled diabetes mellitus (P = 0.059). Goldmann applanation tonometry intraocular pressure correlated to central corneal thickness, while IOPcc and bIOP were independent from central corneal thickness in both groups. All intraocular pressure values showed significant associations to corneal biomechanical parameters. Only in diabetes mellitus, bIOP was correlated to Pachy slope (P = 0.023). Conclusion: In diabetes mellitus, Goldmann applanation tonometry intraocular pressure was slightly, but not significantly, increased, which might be caused by a higher central corneal thickness and changes in corneal biomechanical properties. However, intraocular pressure values measured by Ocular Response Analyzer and Corvis ST were not significantly different between diabetes mellitus patients and healthy subjects. The bIOP showed a higher agreement with Goldmann applanation tonometry than IOPcc and was independent from central corneal thickness.

Relationship between novel intraocular pressure measurement from Corvis ST and central corneal thickness and corneal hysteresis

2019 ◽  
Vol 104 (4) ◽  
pp. 563-568 ◽  
Author(s):  
Masato Matsuura ◽  
Hiroshi Murata ◽  
Yuri Fujino ◽  
Mieko Yanagisawa ◽  
Yoshitaka Nakao ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Central Corneal Thickness ◽  
Linear Regression Analysis ◽  
Corneal Thickness ◽  
Biomechanical Properties ◽  
Applanation Tonometry ◽  
Corneal Hysteresis ◽  
Corneal Resistance Factor ◽  
Corvis St ◽  
The Relationship

AimsCorvis ST (CST) yields biomechanical corrected IOP (bIOP) which is purported to be less dependent on biomechanical properties. In our accompanied paper, it was suggested that the repeatability of bIOP is high. The purpose of the current study was to assess the relationship between intraocular pressure (IOP) measured with CST and central corneal thickness (CCT) and corneal hysteresis (CH), in comparison with IOP measured with Goldmann applanation tonometry (GAT) and the ocular response analyzer (ORA).MethodsA total of 141 eyes from 141 subjects (35 healthy eyes and 106 glaucomatous eyes) underwent IOP measurements with GAT, CST and ORA. The relationships between IOP measurements (ORA-IOPg, ORA-IOPcc, CST-bIOP and GAT IOP) and biomechanical properties (CCT, CH and corneal resistance factor (CRF)) were analysed using the linear regression analysis.ResultsIOPg, IOPcc and GAT IOP were significantly associated with CCT (p<0.001), whereas bIOP was not significantly associated with CCT (p=0.19). IOPg, bIOP and GAT IOP were significantly associated with CH (IOPg: p<0.001; bIOP: p<0.001; GAT IOP: p=0.0054), whereas IOPcc was not significantly associated with CH (p=0.18). All of IOP records were associated with CRF (p<0.001).ConclusionThe bIOP measurement from CST is independent from CCT, but dependent on CH and CRF.

scholarly journals Intraocular pressure changes and corneal biomechanics after hyperopic small-incision lenticule extraction

2019 ◽  
Author(s):  
Dan Fu ◽  
Meiyan Li ◽  
Michael C. Knorz ◽  
Shengsheng Wei ◽  
Jianmin Shang ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Corneal Thickness ◽  
Corneal Biomechanics ◽  
Ocular Response Analyzer ◽  
Small Incision Lenticule Extraction ◽  
Corvis St ◽  
Small Incision ◽  
Lenticule Extraction

Abstract Background: To compare intraocular pressure (IOP) measurements by a dynamic Scheimpflug analyzer (Corvis ST), a non-contact tonometer, and the ocular response analyzer following hyperopic small-incision lenticule extraction (SMILE).Methods: Thirteen patients underwent hyperopic SMILE in one eye each were prospectively enrolled. IOP and corneal biomechanical parameters were measured preoperatively and 1 week, 1 month, and 3 months after surgery with a non-contact tonometer (IOPNCT), Corvis ST (biomechanical corrected IOP, bIOP), and the ocular response analyzer (Goldmann-correlated intraocular pressure [IOPg], cornea compensated IOP [IOPcc]). A linear mixed model was used to compare IOP and biomechanical values among the methods at each time point.Results: IOPNCT, IOPg, and IOPcc dropped significantly after surgery, with the amplitude being 3.15±0.48 mmHg, 5.49±0.94 mmHg, and 4.34±0.97 mmHg, respectively, at the last visit. IOPNCT decreased by 0.11±0.06 mmHg per µm of removed central corneal thickness. bIOP did not change significantly after surgery. Before surgery, no difference was found among the measurements (P> 0.05). After surgery, IOPNCT and bIOP were higher than IOPg and IOPcc. bIOP is independent of cornea thickness at the last visit, while correlated significantly with corneal biomechanics as other three IOP values did.Conclusion: bIOP (biomechanical corrected IOP as measured with the Corvis ST) seems to be an accurate parameter to measure IOP after hyperopic SMILE.

Comparison of intraocular pressure using Goldmann applanation tonometry versus non-contact tonometry in eyes with high-viscosity silicone oil

2019 ◽  
Vol 30 (3) ◽  
pp. 494-499 ◽  
Author(s):  
Dionysios D Pagoulatos ◽  
Zoi G Kapsala ◽  
Olga E Makri ◽  
Ilias G Georgalas ◽  
Constantinos D Georgakopoulos
Keyword(s):  
Intraocular Pressure ◽  
Silicone Oil ◽  
Corneal Thickness ◽  
Measurement Techniques ◽  
High Viscosity ◽  
Applanation Tonometry ◽  
Applanation Tonometer ◽  
Iop Measurement ◽  
Prospective Comparative Study ◽  
Silicone Oil Tamponade

Background: To compare intraocular pressure (IOP) measurements using Goldmann applanation tonometer (GAT) and air tonometer (non-contact tonometry [NT]) in vitrectomized eyes with high-viscosity silicone oil tamponade, as well as in normal eyes. Patients and Methods: In this prospective comparative study, 32 eyes with silicone oil tamponade of high viscosity (5700 CS) and 32 normal fellow eyes were included. IOP was measured by GAT and air tonometer 30 ± 12 days after vitrectomy, while measurements of central corneal thickness (CCT) were also obtained. Results: In eyes with silicone oil, IOP was 20.09 ± 4.91 mmHg and 16.75 ± 3.86 mmHg using contact tonometer and air tonometer, respectively ( p < 0.0001). In normal eyes, IOP was 16.41 ± 2.15 mmHg and 16.31 ± 2.49 mmHg using the same tonometry techniques and this difference was not statistically significant ( p = 0.598). In addition, no significant correlation was detected between IOP measurements using both techniques and age, gender, CCT, and type of lens. Conclusions: It seems that GAT overestimates IOP in eyes with high-viscosity silicone oil compared with NT, while both IOP measurement techniques in normal eyes provide similar values. Further assessment of available IOP measurement methods could possibly establish the most accurate technique for IOP estimation in vitrectomized eyes with silicone oil tamponade.

Ocular Response Analyzer versus Goldmann Applanation Tonometer for Measurement of Intra-Ocular Pressure

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Rim Raafat Fayez ◽  
Mohamed Adel Abdelshafik ◽  
Ahmed Ibrahim Aboulenain ◽  
Momen Mahmoud Hamdi
Keyword(s):  
Corneal Thickness ◽  
Cross Sectional Study ◽  
Applanation Tonometry ◽  
Ocular Response Analyzer ◽  
Cross Sectional ◽  
Goldmann Applanation Tonometer ◽  
Applanation Tonometer ◽  
Iop Measurement ◽  
The Mean ◽  
Method Of Evaluation

Abstract Background Goldmann applanation tonometry (GAT) has been the gold standard for intraocular pressure(IOP) measurement ,since its appearance in clinical practice around 50 years ago.(1) In spite of being almost unchallenged, the last few years have become a sustained search for a new standard method for IOP measurement,. One such recently marketed instrument is the Ocular Response Analyzer (ORA), which able to detect the corneal biomechanics. Aim of the Work is to compare the IOP measurement estimated by Goldmann applanation tonometer to that of ORA and detect the effect of state of refraction, corneal topography and central corneal thickness (CCT) on these measurements. Patients and Methods This cross-sectional study was done from March 2018 to October 2018 on 65 eyes of patients visiting the outpatient clinic. Results The mean GAT IOP was 15.938 ± 6.041 while the mean ORA (IOPcc) and (IOPg) were 19.711 ± 7.59 and 17.242 ± 7.35 mm Hg respectively. There is a strong positive relationship between GAT IOP & ORA IOPg measurement (r = 0.880 – p = &lt;0.001*). Also finding a weak yet significant correlation between IOPg and CCT (r = 0.385, p = 0.001). None of the pressure measurements was affected by refraction or corneal curvature significantly. Conclusion In conclusion, our results suggest that mean IOPs obtained by ORA were significantly higher than that of GAT with different influencing factors that are not completely understood. caution has to be sought when using the ORA, the values obtained ought not to be used interchangeably with the values obtained by 1 GAT, despite the presence of a positive correlation between these values. This underlines the importance of using one and only method of evaluation of the IOP for every patient in successive follow-up visits.

Intraocular Pressure Measurement

Glaucoma ◽  
2012 ◽  
Author(s):  
Manishi Desai
Keyword(s):  
Intraocular Pressure ◽  
Corneal Thickness ◽  
Applanation Tonometry ◽  
Slit Lamp ◽  
Topical Anesthetic ◽  
Fick Principle ◽  
Average Patient ◽  
Risk Of Progression ◽  
Iop Measurement ◽  
To Come

Intraocular pressure (IOP) measurement is a key test by which patients with glaucoma are clinically monitored. Clinical trials have demonstrated that a reduction in IOP results in a reduction in the risk of progression of glaucoma. Accordingly, measuring IOP with relative accuracy is very important in managing patients. There are multiple methods to measure IOP. The method used may depend on the particular clinical setting. All are surrogate measures in comparison to manometry (i.e., IOP measurement using an intracameral cannula), which is the most direct means to measure IOP. However, manometry is not practical for everyday clinical practice since it is invasive. This overview provides information about currently available methods to measure IOP and how they may be best applied. This section also outlines the advantages and disadvantages involved with these methods. Not all techniques are available to every practitioner, but knowing the principles behind these methods and the limitations should allow clinicians to more carefully interpret and reliably obtain IOP measurements using the techniques at their disposal. Goldmann applanation tonometry (GAT) is considered to be the standard by which IOP is measured for the average patient (i.e., average corneal thickness without apparent corneal abnormalities). GAT is also likely the measurement modality most readily available to practitioners. The Perkins tonometer is a handheld Goldmann applanation device (Fig. 1.1B). This is helpful when measuring IOP in children as it can be used in the upright or supine position and for patients unable to come to the slit lamp. Based on the Imbert-Fick principle Applanation diameter is 3.06 mm (not the size of the applanation tip, which is larger), so that 1 g of force represents 10 mmHg. Assumes the eye is a sphere, corneal thickness is estimated to be 0.52 mm, and volume displaced by contact is negligible Instill topical anesthetic and fluorescein dye. Clean tip (see recommended cleaning technique at end of this section). Position patient at slit lamp (for GAT). Set illumination to cobalt blue filter and set force knob/drum to 1 (which corresponds to 10 mmHg).

Comparison between different tonometers following intrastromal corneal ring segments implantation

2021 ◽  
pp. 112067212110425
Author(s):  
Mennatullah M Elfwwal ◽  
Mohamed K Elbasty ◽  
Mohamed F Khattab ◽  
Malak I ElShazly
Keyword(s):  
Intraocular Pressure ◽  
Femtosecond Laser ◽  
Central Corneal Thickness ◽  
Pressure Range ◽  
Corneal Thickness ◽  
Applanation Tonometry ◽  
Ocular Response Analyzer ◽  
P Value ◽  
Cross Sectional ◽  
Intrastromal Corneal Ring

Purpose: To compare different intraocular pressure (IOP) readings in corneas with intrastromal corneal ring segments (ICRS) taken by three different tonometers; Goldmann applanation tonometry (GAT), air puff tonometer, and ocular response analyzer (ORA) corneal-compensated IOP (ORA-IOPcc) and determine the relation of these measurements to different corneal parameters taken by Pentacam. Methods: An observational cross-sectional analytic study included patients who underwent ICRS keraring implantation at 3 months. In each eye, the two rings were placed using the femtosecond laser assisted technique 5.5 or 6 mm from the center. IOP was measured using three different tonometers; GAT, air puff tonometer, and ocular response analyzer (ORA) corneal-compensated IOP (ORA-IOPcc). Results: Fifty eyes of 30 patients (20 males and 10 females) aged 27.56 ± 6.38 years were included. IOP measurements by GAT, air puff tonometer, and ORA-IOPcc were 13.28 ± 2.13 mmHg, 10.47 ± 2.55 mmHg, and 13.19 ± 2.78 mmHg, respectively. Comparisons between air puff and each of GAT and ORA-IOPcc were statistically highly significant ( p-value <0.001). Conclusion: IOP measurements taken by air puff tonometer were significantly lower than those taken by GAT and ORA-IOPcc. These differences were not constant across the pressure range but increased as the pressure values determined using GAT and ORA increased. ORA-IOPcc and GAT showed similar readings. No correlation was found between any of the IOP readings taken by the three tonometers and the central corneal thickness.

scholarly journals Comparability of three intraocular pressure measurement: iCare pro rebound, non-contact and Goldmann applanation tonometry in different IOP group

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Min Chen ◽  
Lina Zhang ◽  
Jia Xu ◽  
Xinyi Chen ◽  
Yuxiang Gu ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Pearson Correlation ◽  
Linear Regression Analysis ◽  
Corneal Thickness ◽  
Intraclass Correlation ◽  
Cross Sectional Study ◽  
Applanation Tonometry ◽  
Cross Sectional ◽  
Wide Range ◽  
Iop Measurement

Abstract Background Measurement of intraocular pressure (IOP) is essential for glaucoma patients. Many factors such as central corneal thickness (CCT) can affect the accuracy of IOP measurement. The purpose of this study was to evaluate the agreement of IOP measured by non-contact tonometer (NCT), iCare pro rebound tonometer (iCare), and Goldmann applanation tonometer (GAT) in different IOP group. Methods This was a Hospital-based cross-sectional study. Two hundred subjects were enrolled in this study. All subjects underwent IOP measurement using an NCT–iCare–GAT sequence. Bland-Altman, Pearson correlation and intraclass correlation analysis were performed using SPSS 17.0 software. The influence of CCT on each IOP measurement methods was evaluated by linear regression analysis. Results The mean difference (Δ) of NCT–GAT did not differ from (Δ) iCare–GAT in IOP < 10 and 10–21 mmHg group. However, (Δ) NCT–GAT was significantly higher than (Δ) iCare–GAT in IOP 22–30 and > 30 mmHg group (P < 0.05). Bland–Altman analysis showed significant agreement between the three devices (P < 0.01). IOP measurements of the three methods were significantly correlated with CCT (P < 0.01). Conclusions ICare pro shows a higher agreement with GAT over a wide range of IOP compared with NCT. The consistency between the three tonometers was similar in a low and normal IOP range. However, NCT shows a greater overestimate of IOP in moderate and higher IOP group. The variability of IOP measurement affected by CCT is NCT > iCare pro > GAT.

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