• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.125-130
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• 2007

The aim of this work was to study the relationship between subjective symptoms and binocular function during near work in forty one(12-17yr) schoolchildren. CISS symptom survey, amplitude of accommodation, accommodative facility, neagative relative accommodation(NRA)/positive relative accommodation(PRA) near point of convergence(NPC), heterophoria, AC/A ratios were measured. The results of measurement were compared with normal expected value of each test and classified into normal and abnormal group. Accommodative insufficiency was more general than convergence insufficiency and esophoria was greater than exophoria. NRA/PRA showed very high and AC/A ratios were very low compare with normal expected value. The results of CISS was as follows; most frequent symptom was tired, mean score was $16.63{\pm}7.49$, mean number of symptoms were $10.07{\pm}3.04$, and mean number of serious symptoms were $1.98{\pm}2.13$. After classified into 4 groups according to score of symptoms, number of symptoms, and degree of symptoms and then analyze the correlation compare with binocular vision test results. NRA was most correlated with group comparison, accommodative facility was most correlated with score of symptoms, NRA was most correlated with number of symptoms, and near horizontal phorias were most correlated with serious symptoms. NRA showed most correlative relation with near symptoms.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.83-88
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• 2008

Purpose: To design an anamorphic aspherical prism lens for the HMD optical system. Methods: First, we get the initial data, needed in design, which are distances between each surface etc., by analyzing user's demended specifications and by drawing geometrically the shape of prism lens by using CAD. Based on these data and using 'ode V' which is an optical design software, we could progress the optimization in which we treat the coefficients of the anamorphic aspherical surface as the principal variables. To reduce the cost in DTM manufacturing, we would optimize the optical system with the transmitting surface, existed in the direction of video device among 3 surfaces of the prism lens, remaining as a plane. Results: we could design one anamorphic aspherical prism lens which has the finite ray aberration of 15 ${\mu}m$, the distortion of 0.5%, and the MTF value of 0.3 over at 36 lp/mm for the video device of 12 mm ${\times}$ 9 mm size. Conclusions: We designed a prism lens used for HMD. This prism lens has the optical capacities of 15 ${\mu}m$ finite ray aberration and 0.5% distortion for the video device of 12 mm ${\times}$ 9 mm size, and become the optical system having the MTF value of 0.3 over at 36 lp/mm.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.419-428
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• 2005

The aim of this study was to provide data for the relief of asthenopia during binocular vision by determining the characteristics of ocular function in adults. A total of 260 subjects were between the age of 19-35years. We measured individually the refractive error correction, pupillary distance, optical center distance, phoria, convergence, accommodation and the AC/A as well as the asthenopia during binocular vision using a questionnaire. After analysis of factors affecting asthenopia, we also examined the reductive effect of asthenopia in subjects who had asthenopia using prism. To determine the factors affecting asthenopia during binocular vision, statistic analyses were carried out the multivariate Logistic regression model. The results of this study were as follow. The asthenopia during binocular vision was found 26.9% of subjects. Multivariate logistic regression model was used to determine factors affecting binocular vision of myopia. When the accommodation and convergence were low compared to being high, when subjects had esophoria or there was more exophoria, and when AC/A was lower than the standard, the rate of asthenopia was higher. Therefore the accommodation, convergence and AC/A could be predictive factors for asthenopia. We used prism for subjects who had asthenopia during binocular vision, the results showed that the symptom of asthenopia was eased up to 74.3%.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.3
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• pp.247-255
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• 2010

Purpose: Developing a roofed Pechan prism type scope with long eye relief. Methods: To reduce the overall length and to lengthen the eye relief of scope, the objective part was designed by adopting the roofed Pechan prism and also the eyepiece part was designed by adopting the field lens with minus refractive power in front of reticle, respectively. Finally, by integrating above two parts, the roofed Pechan prism type scope with 90 mm eye relief was developed. Results: The characteristics of the developed and fabricated scope with 90 mm eye relief by integrating the objective part with the roofed Pechan prism and the eyepiece part with minus refractive power had the magnification of $+3.0{\times}$, the length from the 1st lens to the last lens of about 121 mm, the barrel diameter of 28 mm, and the effective objective-diameter of 17 mm. Also it was found that the line width of resolution was about 900 cycles/rad at the 50% MTF value criterion. Conclusions: We could design and manufacture the roofed Pechan prism type scope with 90 mm eye relief, the characteristics of which had the magnification of $3.0{\times}$, the MTF above 50% at 900 cycles/rad, and the length from the 1st lens to the last lens of about 121 mm.

• Korean Journal of Microbiology
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• v.47 no.2
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• pp.151-157
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• 2011

This study was to examine the quality characteristics and biological activities of the yogurt containing dual fermentation MFCY (Monascus-Fermented Chinese Yam) powder. Six different contents (0, 0.1, 0.3, 0.5, 1.0, and 2.0%, w/v) of MFCY powder were added to raw milk and 5% skim milk followed by fermentation with lactic acid bacteria at $37^{\circ}C$ for 12 h, and then the biological activities of the samples were investigated. Biological activities of the prepared yogurt were evaluated for acid production (pH, titratable acidity), number of viable cells, total polyphenol contents, DPPH radical scavenging activity, reducing power, angiotensin converting enzyme inhibitory effects and GABA contents. In this study, the results show that after fermentation in raw milk and 5% skim milk added with MFCY powder. The yogurt can produced pH, titratable acidity, number of viable cells, total polyphenol contents, DPPH radical scavenging activity and reducing power at 4.12-4.25 (pH), 0.94-0.97% (TA), $7.50{\times}10^9-1.14{\times}10^{10}$ CFU/ml, 161.4-329.9 (TP, mg/L), 54-94% (DPPH), and 1.13-1.53 (R.P), respectively. In addition, the showed ACE inhibitory activity and GABA contents was 67.1-87.7% and 304.6-685.4 (mg/L).

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.3
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• pp.7-15
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• 2009

Purpose: To investigate the corneal recovery after discontinuing orthokeratology (OK) lenses wear in children for long-term period. Methods: Among the OK lens wearers who wear over 8 months and showed successful refractive correction, 25 subjects were selected who want to discontinue the OK lenses. Uncorrected visual acuity, refractive correction, corneal curvature (Sim K), central corneal thickness and corneal eccentricity were measured during the OK lens wearing period and after discontinuation for 1 month. Results: Uncorrected visual acuity and corneal shape had remodeled significantly during the OK lens wear and recovered significantly during the first week of discontinuation. Uncorrected visual acuity and refractive correction had achieved full recovery 2 weeks after discontinuation of lens wear and were highly correlated with the changes in corneal thickness. But corneal shape recovered slowly, eccentricity had recovered fully after 1 month and corneal curvature and central thickness had not been achieved full recovery until 1 month after discontinuation. Conclusions: Recovery of after longterm use of OK lens is rapid for refractive change, but slow for corneal curvature and central thickness that to refit the contact lenses, practitioners need patience.

• Journal of Life Science
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• v.21 no.8
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• pp.1142-1148
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• 2011

This study was conducted to investigate antioxidative and physiological activities of ethanol extracts concentration from Monascus-Fermented Chinese Yam (MFCY). The ethanol extracts from MFCY were measured to examine pigment, monacolin K content, total polyphenol content, DPPH radical scavenging activity and angiotensin converting enzyme inhibitory effects. In this study, the results show that Monascus sp. MK2, with Dioscorea batatas Dence. as the substrate, can produce pigments (red, orange, and yellow), monacolin K content, total polyphenol content and DPPH radical scavenging activity at 13.48 (red), 11.66 (orange), 12.77 (yellow), 462.78 (mg/kg), 658.8 (mg/kg) and 92.8% in EtOH extract, respectively. In addition, ACE inhibitory activity was shown to be 74.55% in EtOH extract. Therefore, it can be concluded that Dioscorea batatas Dence is the best fermentative substrate for Monascus species to produce secondary metabolites as biomedicinal substances.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.2
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• pp.17-22
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• 2008

To develop an imaging optical system for the 545 nm fluorescent plate of X-ray. Methods: We designed and manufactured a new imaging optical system for the 545 nm fluorescent plate of X-ray by Sigma 2000 program after deciding the design comparison standards referred to Canon CX2-70 model. Results: The characteristics of the new imaging optical system for the 545 nm fluorescent plate of X-ray have the magnification of -0.225x, the image field size of $90mm{\times}90mm$, and the 0.033 mm resolution line width at the 30% MTF value criterion. These mean that the new model has a capability of deciphering for the more large screen and the resolution of deciphering is superior to that of Canon CX2-70 model. Also the image side NA (-0.196) of the new model is about $\sqrt{2}$ times than that (-0.139) of CX2-70 and the object side NA (0.044) of the new model is about 2 times than that (0.022) of CX2-70. These mean that the sensitivity of the film in the new design model is able to be increased to about 4 times and there is the possibility of reducing the bombed time of X-ray to 1/4 times. Conclusions: We could design and manufacture the imaging optical system for the 545 nm fluorescent plate of X-ray having the possibility of reducing the bombed time of X-ray to 1/4 times in comparision to Canon CX2-70 model, the characteristics of which have the image field size of $90mm{\times}90mm$ and the MTF of 30% or more at 15 lines/mm criterion.

• Journal of Korean Clinical Health Science
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• v.9 no.1
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• pp.1478-1485
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• 2021

Purpose. To analysis of astigmatism in Korean adults from 20 to 29 years old. Methods. From January 2019 to February 2020, one hundred two subjects were performed in refraction test using the Auto-Refractometry. Results. In the type of astigmatism based on refractive error, the male's right eye was 4.26% simple myopic astigmatism and 95.74% complex myopic astigmatism, and the left eye was 2.22% simple myopic astigmatism and 97.78% complex myopic astigmatism. However, in the female's right eye, simple myopic astigmatism was 2.27%, complex myopic astigmatism was 97.73%, and left eye was simple myopic astigmatism was 2.17%, complex myopic astigmatism was 97.83%. The types of astigmatism in men and women similar to other. The mean refractive astigmatism values were -0.922±-0.798 diopter and -0.877±-0.707 diopter for male right and left eye, and -0.765±-0.599 diopter and -0.853±-0.586 diopter for female. On the other hand, the refraction values of the right and left eyes of men and women have statistical significance(p=0.000). The mean power comparative between refractive astigmatism and corneal astigmatism power were -0.186±-0.745 diopter, -1.091±-0.589 diopter in male and -1.140±-0.593 diopter, -1.140±-0.534 diopter in female. Therefore, the mean power values of the refractive astigmatism and corneal astigmatism of men and women were statistical significance(p=0.000). At the 0.75 diopter or more, which can have clinical symptoms of astigmatism power, males have 60.86% and 72.09% of the right and left eyes, and females have 47,64% and 60.10% of the right and left eyes. At 0.75 diopter or more, which can have clinical symptoms of corneal astigmatism power, males have 68.75% and 74% of the right and left eyes, and females have 86.50% and 82.35% of the right and left eyes. In the type of astigmatism axis, both men and women had a high frequency of the rule astigmatism. However, men had a high frequency of against-the-rule astigmatism and women showed a high frequency of oblique astigmatism. Conclusions. In this study, the complex myopic astigmatism and with-the rule astigmatism was the most common of all subjects. However, there was a statistical significance between right and left eyes of all subjects. The corneal astigmatism was higher refractive values in both males and females than refractive astigmatism. This study suggests that the analysis of the astigmatism can provide the useful diagnosis information for the correction of visual acuity.

• 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.