scholarly journals Quantitative Assessment of the Impact of Blood Pulsation on Intraocular Pressure Measurement Results in Healthy Subjects

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Robert Koprowski ◽  
Lei Tian

Background. Blood pulsation affects the results obtained using various medical devices in many different ways. Method. The paper proves the effect of blood pulsation on intraocular pressure measurements. Six measurements for each of the 10 healthy subjects were performed in various phases of blood pulsation. A total of 8400 corneal deformation images were recorded. The results of intraocular pressure measurements were related to the results of heartbeat phases measured with a pulse oximeter placed on the index finger of the subject’s left hand. Results. The correlation between the heartbeat phase measured with a pulse oximeter and intraocular pressure is 0.69±0.26 (p<0.05). The phase shift calculated for the maximum correlation is equal to 60±40° (p<0.05). When the moment of measuring intraocular pressure with an air-puff tonometer is not synchronized, the changes in IOP for the analysed group of subjects can vary in the range of ±2.31 mmHg (p<0.3). Conclusions. Blood pulsation has a statistically significant effect on the results of intraocular pressure measurement. For this reason, in modern ophthalmic devices, the measurement should be synchronized with the heartbeat phases. The paper proposes an additional method for synchronizing the time of pressure measurement with the blood pulsation phase.

2019 ◽  
Vol 30 (6) ◽  
pp. 1432-1439 ◽  
Author(s):  
Lisa Ramm ◽  
Robert Herber ◽  
Eberhard Spoerl ◽  
Lutz E Pillunat ◽  
Naim Terai

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Mengwei Li ◽  
Bingxin Zheng ◽  
Qi Wang ◽  
Xinghuai Sun

Purpose. To compare the impact of visual field (VF) testing on intraocular pressure (IOP) change trends between healthy subjects and glaucoma patients. Methods. We recruited healthy volunteer subjects who did not have previous ocular diseases and open-angle glaucoma patients who were medically controlled well. IOP in both eyes of each participant was measured by using a noncontact tonometer at five time points: before, immediately after (0 minute), and 10, 30, and 60 minutes after the standard automated perimetry. Repeated measures ANOVA was used to analyze the effect of VF testing on IOP change trends in healthy and glaucoma eyes. Results. Forty healthy subjects (80 eyes) and 31 open-angle glaucoma patients (62 eyes) were included for the study. The baseline IOP of healthy and glaucoma eyes was 16.11 ± 3.01 mmHg and 15.78 ± 3.57 mmHg, respectively. After the VF testing, the IOP in healthy eyes was decreased by 1.5% at 0 minute, 6.5% at 10 minutes (P<0.001), 6.6% at 30 minutes (P<0.001), and 7.0% at 1 hour (P<0.001), indicating that this reduction was sustained for at least 1 hour. However, the IOP in glaucoma eyes was increased by 12.7% at 0 minute (P<0.001) and, then, returned towards initial values 1 hour after the VF testing. Conclusions. IOP change trends after VF field testing between healthy subjects and glaucoma patients were quite different. VF testing led to a mild and relatively sustained IOP decrease in healthy subjects, whereas IOP in open-angle glaucoma patients tended to significantly increase immediately after VF testing and, then, returned to pretest values after 1 hour. These findings indicate that the factors of VF testing should be considered in the clinical IOP measurements.


2017 ◽  
Vol 26 (3) ◽  
pp. 278-282 ◽  
Author(s):  
Karin R. Pillunat ◽  
Eberhard Spoerl ◽  
Naim Terai ◽  
Lutz E. Pillunat

2021 ◽  
Vol 18 ◽  
Author(s):  
Linlin Zhao ◽  
Guanghua Liu ◽  
Lingli Zhang ◽  
Yuxiang Du ◽  
Le Lei ◽  
...  

Background: Alzheimer's disease (AD) is a chronic neurodegenerative disease which has been characterized by progressive development of long onset early disease with complicated etiology, and may cause memory loss, cognitive impairment, and behavioral changes. Physical exercise may play a preventive role in AD. In the present study, we investigated the impact of longer-term physical exercise on finger tapping of AD patient by comparing the finger tapping of AD patients and heathy controls without AD. Methods: In this study, 140 subjects who aged ≥ 60 years were enrolled. Group A consisted of 70 subjects (27 males and 43 females) without exercise habits who selected from Yangpu District (Shanghai, China). Group B consisted of 70 subjects (27 males and 43 females) who selected from Minxing District (Shanghai, China). All the subjects were right-handed as well. The subjects’ data, including subjects’ age, weight, height, Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), and finger tapping frequency were measured. Results: The subjects were matched in age, weight, and height. The AD subjects’ MoCA and MMSE scores were noticeably lower than healthy subjects’ scores (P<0.001); besides, AD patients with exercise have significantly lower MoCA and MMSE scores than healthy controls with exercise (P<0.001). The finger tapping of AD subjects’ left hands was significantly lower than that of healthy subjects without AD (P<0.01), and AD subjects with exercise tapped significantly slower with left hand than healthy subjects with exercise (P<0.01). Meanwhile, AD subjects with exercise tapped significantly faster with left hand than AD subjects (P<0.05). The right hands of AD subjects tapped remarkably less than healthy subjects (P<0.01) with or without exercise. Meanwhile, subjects with exercise tapped significantly faster with right hand than healthy subjects (P<0.05), and AD subjects with exercise tapped significantly faster with right hand than AD subjects (P<0.05). Conclusion: Long-term physical exercises can improve finger tapping frequency, especially patients with AD. Finger tapping frequency may be used as an index to monitor cognitive decline in ageing AD patients.


2013 ◽  
Vol 22 (7) ◽  
pp. 584-590 ◽  
Author(s):  
Matthias Neuburger ◽  
Philip Maier ◽  
Daniel Böhringer ◽  
Thomas Reinhard ◽  
Jens F. Jordan

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