• Journal of the Korean Society for Precision Engineering
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• v.24 no.9
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• pp.17-22
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• 2007

• Journal of Veterinary Clinics
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• v.19 no.4
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• pp.415-417
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• 2002

To investigate the diurnal change of intraocular pressures(IOP) and compare of $Tono-pen^{XL}$ and Schi$\emptyset$tz tonometer, we measured the IOP in clinically normal eyes of dogs. To estimate the diurnal change of IOP, the measurements of IOP were taken with $Tono-pen^{XL}$ in 44 normal canine eyes. Two physicians measured the IOP through the central cornea and limbal cornea. To compare of two tonometers, a physician measured the IOP with both $Tono-pen^{XL}$ and Schi$\emptyset$tz (7.5 g) tonometer in 23 clinically normal eyes of dogs. Mean of lOP was 26.51 $\pm$ 6.91 mmHg and IOP was highest as 30.65 mmHg at a.m. 10, but not significantly different within physicians and corneal regions (p > 0.05). Correlation coefficient within two tonometers was too low.

• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1122-1128
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• 2018

Purpose: To compare the measurements of the rebound tonometer (RT), Goldmann applanation tonometer (GAT) and noncontact tonometer (NCT) in patients who underwent penetrating keratoplasty (PKP), and to evaluate the reproducibility of the RT measurements. Methods: This study included 19 PKP eyes and 28 normal eyes. We compared the intraocular pressure (IOP) measurements of the GAT and NCT with the RT in both groups using Spearman's correlation analysis and the Wilcoxon signed-rank test. The IOP, as measured with an RT in each group, was assessed with respect to reproducibility using the intraclass correlation coefficient (ICC). Results: In normal eyes, there was no significant difference in the measurements obtained with the RT, GAT, and NCT (p > 0.050). In the patient group, the RT measurements were not significantly different from those of the GAT (p = 0.872), but they were significantly lower than those obtained with the NCT (p = 0.011). However, the RT measurements showed a relatively high correlation with those of the GAT and NCT (r = 0.770 and 0.879, respectively). The ICC of the RT was 0.986 for the PKP eye group and 0.961 for the normal eye group, both of which were highly reproducible. Conclusions: In PKP eyes, the measurements obtained with the RT showed a relatively high correlation with those of the GAT and NCT, and the repeatability of the RT measurements was high and similar to those for normal eyes. The RT can therefore be considered a useful method for measuring the IOP in PKP eyes.

• Journal of Yeungnam Medical Science
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• v.11 no.2
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• pp.277-283
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• 1994

We studied the change in intraocular pressure (IOP) in 15 consecutive cataract patients who underwent extracapsular cataract extraction and posterior chamber lens implantation between Feb. 1993 and Apr. 1993 to evaluate the effect of this surgery on postoperative IOP. To evaluate the clinical usefulness of non-contact tonometer, the intraocular pressures were measured with Kowa non-contact tonometer (TM-2000, Japan) as well as Goldmann applanation tonometer. There was a decrease in IOP of $3.4{\pm}2.9$mmHg (p<0.00l) 3 months after this surgery and the intraocular pressure differences between pseudophakic eyes and contralateral phakic eyes at 3 months postoperatively were $2.4{\pm}3.8$mmHg (p<0.05). The correlation coefficient between non-contact tonometer and Goldmann tonometer was 0.8876 (p=0.001) in the postoperative 76 eyes. Therefore, our results suggest that extracapsular cataract extracion and posterior chamber lens implantation alone can be a useful surgical method in cataract patient with ocular hypertension, and non-contact tonometer was relatively accurate in measuring the postoperative intraocular pressure.

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2008.10a
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• pp.163-163
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• 2008

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2006.11a
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• pp.104-104
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• 2006

• Journal of Korean Clinical Health Science
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• v.11 no.1
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• pp.1632-1638
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• 2023

Purpose: The aim of this study was to determine the distribution of the cornea thickness and intra ocular pressure Korean adult of 20 to 24 year old using the Pentacam and tonometer. Methods: The subjects of this study were 43 Korean adults with healthy eyes. Corneal thickness was measured with Pentacam device. The intra ocular pressure was measured with tonometer. Data was analyzed by means of the Pearson's correlation cofficient. P-values<0.001 were considered statistically significant. Results: Mean age of subjects was 20.41±0.86 years. The mean +/- intra ocular pressure of the right eye and left eye were 16.236±2.523mmHg and 16.971±1.992mmHg, respectively. The mean central corneal thickness of the right eye and left eye was 545.324±38.682㎛ and 547.442±33.778㎛, respectively. No significant difference in central corneal thickness was found between the right and left eyes. But, there was a statistically significant difference between central cornea thickness and peripheral cornea thickness around 4 mm of central cornea(p<0.001, Pearson's correlation). However there was no statistically significant difference between central cornea thickness and intra ocular pressure. Conclusion: The results of this study could be used as a clinical reference data for diagnosis and treatment of cornea in Korean adult.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.589-596
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• 2018

Purpose : We compared intraocular pressure (IOP) values measured by two types of tonometers in condition of normotensive and glaucomatous rat model. We tried to determine which of tonometer can more easily and accurately measure the IOP of animal model. Methods : Glaucomatous eyes were induced by intracameral injections of hyaluronic acid in right eyes of six-week-old male Spargue-Dawley (SD) rats. Normotensive contralateral eyes were left eyes of the SD rats. IOP was measured using a rebound tonometer (Tonolab) and a immersive tonometer ($Tonopen^{(R)}$ XL) about 3:00 pm. Results : The mean IOP values of normotensive control eyes were $10.80{\pm}1.03mmHg$ by Tonopen, and $15.10{\pm}0.73mmHg$ by Tonolab. They were statistically insignificant (p = .1). The mean IOP values of glaucomatous experimental eyes were $30.20{\pm}2.67mmHg$ by Tonopen, and $37.90{\pm}2.73mmHg$ by Tonolab. They were statistically insignificant (p = .95). High IOP values of glaucomatous eyes by two types of tonometers had strong positive correlation each other (r = .904, p < .01). Conclusion : This is the first study to compare IOP values using two types of tonometers between normotensive and glaucomatous model made by intracameral injection of hyaluronic acid. Tonopen should be used carefully when the IOP is within normal range, and both Tonopen and Tonolab can be used reliably when the IOP is high.

• Journal of the Optical Society of Korea
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• v.10 no.4
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• pp.145-156
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• 2006

In the field of ophthalmology, many diagnostic instruments based on optical technology have been developed, such as refractometer, keratometer, corneal mapper, tonometer, fundus camera, slit lamp, laser scan ophthalmoscope and optical coherence tomography. Among them, the refractometer that is used for measuring the refractive power of the human eye has the long research history and various types have been developed. However the efforts to realize more accurate and precise measurement are still in progress. The wavefront analyzer commercialized in recent years is an excellent outcome of such efforts. In this paper, a brief account of the developmental history of various refractometers including the wavefront analyzer is summarized, and the underlying measurement principle is introduced in the view of optics. Finally, the technical issues that should be solved for getting better performance are discussed.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.131-135
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• 2008

Purpose: To measure and quantify the factors of intraocular pressure (IOP) variation for normal Korean youth. Methods: The IOP of normal youth 805 persons (male: 367, female: 438) were measured as a function of time and quantity for fixation, reclining posture, hard blinking, drinking water, drinking hard liquor, tobacco and coffee by using non-contact tonometer (AT555, Reichert Co.). In the case of fixation, reclining posture and hard blinking, the intraocular pressure of right and left eye were measured for 6 males and 6 females every 10 minutes during 30 minute. In the case of water, liquor, tobacco and coffee, the measurement for 4 or 5 groups (6 persons/ group) having similar IOP were done for the IOP variation of right eye. Results: The mean IOP was 15.2 mmHg for males and 15.8 mmHg for females (slightly higher than male's), respectively and the 99% of those were in the range of the normal IOP. The measured IOP was increased by fixation, reclining posture and hard blinking with males and females. The gradient of increasing slope was 0.15/0.13/0.07/0.08, 0.09/0.08/0.08/0.08 and 0.19/0.08/0.26/0.31, respectively. The IOP variation was elevated by drinking water (especially in the case of 1000 ml) and lowered in proportion to the amount of drinking by hard liquor. Cigarette smoking was associated with rise in intra ocular pressure, but was not shown a definite relation. And coffee had virtually no effect. Conclusions: Fixation, reclining posture, hard blinking and Tobacco caused a transient increase in IOP, but alcohol elicited a slight reduction in IOP overall.