scholarly journals Dynamic contour tonometry in asymmetric glaucoma patients

2012 ◽  
pp. 555
Author(s):  
Emilio Rintaro Suzuki Jr.
Keyword(s):  
Dynamic Contour Tonometry ◽  
Asymmetric Glaucoma

Comparison of Goldmann applanation and dynamic contour tonometry before and after cataract surgery

2012 ◽  
Vol 38 (4) ◽  
pp. 683-689 ◽  
Author(s):  
Mitja A. Heinrich ◽  
Timo Eppig ◽  
Achim Langenbucher ◽  
Sven Walter ◽  
Wolfgang Behrens-Baumann ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Dynamic Contour Tonometry ◽  
Before And After

Intraocular Pressure and Ocular Pulse Amplitude Comparisons in Different Types of Glaucoma Using Dynamic Contour Tonometry

2006 ◽  
Vol 31 (10) ◽  
pp. 851-862 ◽  
Author(s):  
Omar S. Punjabi ◽  
Hoai-Ky V. Ho ◽  
Christoph Kniestedt ◽  
Alan G. Bostrom ◽  
Robert L. Stamper ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Pulse Amplitude ◽  
Dynamic Contour Tonometry ◽  
Ocular Pulse Amplitude ◽  
Different Types ◽  
Ocular Pulse

Comparison of dynamic contour tonometry and Goldmann applanation tonometry following penetrating keratoplasty

2010 ◽  
Vol 45 (5) ◽  
pp. 489-493 ◽  
Author(s):  
Artemios Kandarakis ◽  
Vasileios Soumplis ◽  
Christos Pitsas ◽  
Stylianos Kandarakis ◽  
Jiannis Halikias ◽  
...  
Keyword(s):  
Penetrating Keratoplasty ◽  
Applanation Tonometry ◽  
Goldmann Applanation Tonometry ◽  
Dynamic Contour Tonometry

Nycthemeral Rhythm of the Frequency and Biomechanical Energy of High Frequency Intraocular Pressure Fluctuations

2013 ◽  
Author(s):  
Vincent Libertiaux ◽  
William P. Seigfreid ◽  
Massimo A. Fazio ◽  
Juan F. Reynaud ◽  
Claude F. Burgoyne ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
High Frequency ◽  
Pressure Fluctuations ◽  
Low Frequency ◽  
Pulse Amplitude ◽  
Mean Value ◽  
Multiple Time Scales ◽  
Dynamic Contour Tonometry ◽  
Multiple Time ◽  
Ocular Pulse

The optic nerve head (ONH) is the site of insult in glaucoma, the second leading cause of blindness worldwide. Intraocular pressure (IOP) is commonly regarded as a major factor in the onset and progression of the disease1 and lowering IOP is the only clinical treatment that has been shown to retard the onset and progression of glaucoma2. However, many patients continue to progress even at an epidemiologically-determined normal level of IOP3. This suggests that in addition to the mean value of IOP, IOP fluctuations could be a factor in glaucomatous pathophysiology. The importance of low frequency fluctuations of clinically-measured mean IOP remains controversial. These studies all rely on snapshot measurements of mean IOP at each time point, and those measurements are taken at relatively infrequent intervals (hourly at the most frequent, but usually monthly or longer). Recently however, there has been some interest in ocular pulse amplitude, or the fluctuation in IOP associated with the cardiac cycle, which can be measured by Dynamic Contour Tonometry (DCT). DCT provides continuous measurement of IOP, but only for a period of tens of seconds in which a patient can tolerate corneal contact without blinking or eye movement, which ironically are two of the most common sources of large high frequency IOP fluctuations according to our telemetric data collected from monkeys4 and previous human studies. In a recent report, continuous IOP telemetry was used in three nonhuman primates to characterize IOP dynamics at multiple time scales for multiple 24-hour periods5.

The Afferent Pupillary Defect in Asymmetric Glaucoma

1987 ◽  
Vol 105 (11) ◽  
pp. 1540-1543 ◽  
Author(s):  
R. H. Brown ◽  
J. D. Zilis ◽  
M. G. Lynch ◽  
G. E. Sanborn
Keyword(s):  
Asymmetric Glaucoma

scholarly journals Non-invasive Clinical Measurement of Ocular Rigidity and Comparison to Biomechanical and Morphological Parameters in Glaucomatous and Healthy Subjects

2021 ◽  
Vol 8 ◽  
Author(s):  
Yanhui Ma ◽  
Sayoko E. Moroi ◽  
Cynthia J. Roberts
Keyword(s):  
Healthy Subjects ◽  
High Speed ◽  
Morphological Characteristics ◽  
Volume Ratio ◽  
Pulse Amplitude ◽  
Morphological Characterization ◽  
Dynamic Contour Tonometry ◽  
Stiffness Parameter ◽  
Positive Correlation

Purpose: To assess ocular rigidity using dynamic optical coherence tomography (OCT) videos in glaucomatous and healthy subjects, and to evaluate how ocular rigidity correlates with biomechanical and morphological characteristics of the human eye.Methods: Ocular rigidity was calculated using Friedenwald's empirical equation which estimates the change in intraocular pressure (IOP) produced by volumetric changes of the eye due to choroidal pulsations with each heartbeat. High-speed OCT video was utilized to non-invasively measure changes in choroidal volume through time-series analysis. A control-case study design was based on 23 healthy controls and 6 glaucoma cases. Multiple diagnostic modalities were performed during the same visit including Spectralis OCT for nerve head video, Pascal Dynamic Contour Tonometry for IOP and ocular pulse amplitude (OPA) measurement, Corvis ST for measuring dynamic biomechanical response, and Pentacam for morphological characterization.Results: Combining glaucoma and healthy cohorts (n = 29), there were negative correlations between ocular rigidity and axial length (Pearson R = −0.53, p = 0.003), and between ocular rigidity and anterior chamber volume (R = −0.64, p = 0.0002). There was a stronger positive correlation of ocular rigidity and scleral stiffness (i.e., stiffness parameter at the highest concavity [SP-HC]) (R = 0.62, p = 0.0005) compared to ocular rigidity and corneal stiffness (i.e., stiffness parameter at the first applanation [SP-A1]) (R = 0.41, p = 0.033). In addition, there was a positive correlation between ocular rigidity and the static pressure-volume ratio (P/V ratio) (R = 0.72, p < 0.0001).Conclusions: Ocular rigidity was non-invasively assessed using OCT video and OPA in a clinic setting. The significant correlation of ocular rigidity with biomechanical parameters, SP-HC and P/V ratio, demonstrated the validity of the ocular rigidity measurement. Ocular rigidity is driven to a greater extent by scleral stiffness than corneal stiffness. These in vivo methods offer an important approach to investigate the role of ocular biomechanics in glaucoma.

scholarly journals Travoprost- and Tafluprost-induced Changes in Intraocular Pressure and Ocular Pulse Amplitude

2021 ◽  
Vol 62 (9) ◽  
pp. 1235-1242
Author(s):  
Gyeong Min Lee ◽  
Seung Joo Ha
Keyword(s):  
Intraocular Pressure ◽  
Open Angle Glaucoma ◽  
Pulse Amplitude ◽  
Applanation Tonometry ◽  
Dynamic Contour Tonometry ◽  
Long Term Effects ◽  
Ocular Pulse Amplitude ◽  
Induced Changes ◽  
First Time ◽  
Ocular Pulse

Purpose: To compare the intraocular pressure reduction and changes in ocular pulse amplitude of travoprost 0.003% and tafluprost 0.0015%. Methods: We assessed patients who were diagnosed with open-angle glaucoma from January 2017 to July 2019 for the first time at our hospital. Forty-two eyes were assigned to the travoprost group (23 patients) and 26 eyes were assigned to the tafluprost group (14 patients). Changes in intraocular pressure were measured by Goldmann applanation tonometry (GAT), and corrected ocular pulse amplitude (cOPA) was measured using dynamic contour tonometry. Changes in these parameters were observed and compared for 1 year. Results: No significant differences were observed between the GAT measurements and the cOPA of patients treated with travoprost and tafluprost for 1 year (p = 0.512, p = 0.105). The change in initial intraocular pressure on GAT observed after 1 week was -5.32 ± 2.63 mmHg for travoprost and -3.79 ± 3.19 mmHg for tafluprost (p = 0.0457). The initial change in cOPA was +0.04 ± 0.9 mmHg in the travoprost group and -0.76 ± 0.97 mmHg in the tafluprost group (p = 0.0028). Conclusions: Travoprost and tafluprost reached the targeted intraocular pressure with no difference in the long-term effects of reduced intraocular pressure. However, travoprost was initially better at lowering intraocular pressure faster, and tafluprost had a greater effect on lowering OPA. Prostaglandin analogs can be selected individually by considering the aforementioned factors.

The Accuracy of Dynamic Contour Tonometry Over Soft Contact Lenses

2013 ◽  
Vol 90 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Fabrice Gogniat ◽  
Daniela Steinegger ◽  
Daniela S. Nosch ◽  
Roland Joos ◽  
Michael Goldschmidt
Keyword(s):  
Contact Lenses ◽  
Dynamic Contour Tonometry ◽  
Soft Contact ◽  
Soft Contact Lenses

Management of Glaucoma Following Intraocular Procedures

Glaucoma ◽  
2012 ◽  
Author(s):  
Raghu C. Mudumbai
Keyword(s):  
Refractive Surgery ◽  
Structural Integrity ◽  
Corneal Thickness ◽  
Topical Steroid ◽  
Applanation Tonometry ◽  
Dynamic Contour Tonometry ◽  
Glaucomatous Optic Neuropathy ◽  
Clinical Appearance ◽  
Clinical Procedures ◽  
Pressure Spike

The development of glaucoma can occur postoperatively from corneal/refractive, cataract, and vitreoretinal surgery. Additionally, glaucoma may be noted after clinical procedures have been performed, including injections and laser procedures. This chapter is organized into two basic sections: postoperative and post-procedure glaucoma. Background: Currently little is known about the effect of refractive surgery in glaucoma patients or about patients who undergo refractive procedures and may go on to develop glaucoma. •IOP measurement •Measurement of IOP after refractive surgery can be challenging. Corneal properties that are altered after refractive surgery include corneal thickness, corneal curvature, the structural integrity (stiffness or hysteresis), as well as the overlying tear film that interacts with instruments that measure IOP. Photorefractive keratectomy (PRK) additionally ablates portions of Bowman’s layer, which may change corneal resistance. Nomograms have been developed to adjust for IOP change after corneal alteration but usually take only corneak thickness into account, which has led to little success in their use. •Goldmann applanation tonometry (GAT) assumes corneal thickness = 520 microns. Thicker corneas will overestimate IOP and thinner corneas, which result from refractive procedures such as PRK and LASIK, will underestimate IOP. Therefore, GAT may have limited value in measuring true IOP following refractive surgery. Other tonometric devices, like Pascal dynamic contour tonometry, pneumatonometry, and the Reichert ocular response analyzer, may be more accurate. There does not appear to be any simple conversion table that can be referenced in correcting measured IOP after the cornea is altered surgically. Preoperative IOP is probably the most important variable that should be recorded. •The intraoperative pressure spike associated with LASIK may occur in select patients, leading to the development of glaucomatous optic neuropathy. • Pressure-induced stromal keratitis (PISK) is a condition related to steroid-induced elevated IOP that may occur after LASIK. The clinical appearance is similar to diffuse lamellar keratitis (DLK), where there is a diffuse interlamellar haze covering the flap. DLK is an inflamatory response where IOP is not elevated and requires topical steroid treatment for resolution.

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