• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.59-63
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• 2008

Purpose: The purpose of this study is to understand a relation of water content measurement with two different method, water removal method and dry method. Methods: 72 hydrogel contact lens containing various water content (ranged from 47% to 58%) were measured by the gravimetric method at 20$^{\circ}C$and 21% of the humidity. We weighed the dried test specimen at room temperature for 30 min after cooling. Results: In dry blotting method, the water content was measured to 47.43${\pm}$8.48%. The water contents was measured to 48.15${\pm}$8.36% with wet blotting condition. It was found that wet blotting method showed the higher water content of about 7% than dry blotting method. In water content with two dry methods, each of results was measured by 47.89${\pm}$8.06% and 49.56${\pm}$7.06%. In case of microwave method, the water content was measured significantly higher water content of about 1.67% than vacuum oven method. However, no statistical difference was found (p>0.05). Conclusions: In water removal method (Dry blotting method and Wet blotting method) to weigh hydrated test specimen, wet blotting method showed significantly higher water content than dry blotting method. Also in case of dry methods (vacuum oven and microwave) to weigh dry test specimen, water content of microwave method showed higher water content than vacuum oven method, but it should be noted that microwave oven method must be used carefully to measure accurateness on the specimen position and wave power.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.69-80
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• 2009

Purpose: We investigated validity of a monitor-based computer eye test program, Test Chart 2000 Pro (developed by Thomson Software Solutions, UK). Methods: We chose ten common eye tests of the Test Chart 2000 Pro and Korean Standard Eye Test, applying them to same subject groups each by each, followed by comparison and analyses of agreement degree of the results. Results: Among the ten eye tests, Snellen Chart, Cross-cyl target, Duochrome test, Fan and Block test, and Random dot stereograms showed statistically significant agreement between both the Korean standard eye test method and Test Chart 2000 Pro. On the other hand, some disagreements were found between the two eye test methods in LogMAR Chart, Single Letter Chart, Phoria Test, Fixation Disparity Test, and Worth 4 Dot Test. Conclusions: Comparing to the Korean Standard Eye Test that consists of Han eye chart and Phoroptor, validity of the Test Chart 2000 Pro is not so high. Further improvements of the Test Chart 2000 Pro in accuracy are required.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.95-99
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• 2007

This study performed apreliminary test with male high school students in Gwangju metropolitan city in order to determine visual function information of high school students. For the items in this preliminary test, there were inquiry, test for long distance unaided visual acuity, pinhole visual acuity test, colour vision test, cover test and stereo test. Most complaint related to eye was about blurred vision (28.4%) and over 90% of subjects had one or more, and among them, over 50% appealed two or more complaints. 76.1% of all subjects showed less than 0.7 in unaided distance visual acuity. In pinhole visual acuity test, 98% had an improved unaided pinhole visual acuity and most of them experienced an improvement and 2% had no change or dropped. The students with normal stereoscopic vision test were 85.6% and the students under normal range were 14.4%. In colour vision test, 7.9% of them were protanomaly and deuteranomaly and none of them had trichromasy and total color blindness. In cover test, it showed 30.2% of orthophoria, 8.2% of esophoria and 61.5% of exophoria, and none of them had strabismus.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.2
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• pp.67-78
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• 2007

The eye irritant test of lens washing agent, CLIWELL$^{TM}$ was conducted using Draize methods according to KFDA Guidelines. In addition, to test the potential toxicity of test articles, the ratio of inflammatory cells and non-inflammatory epitheloid cells was also observed using smear cytology methods against ocular discharge. At sacrifice, the histopathological changes on Cornea, Iris, Retina and Sclera were also observed in all animals. Slight irritancy of cornea and conjunctiva was observed at 1, 2 and 3 days after dropping in non-washing group. The MIOI of these points are detected as 4.50, 1.67 and 0.67, respectively. In washing group, slight irritancy of cornea and conjunctiva were observed at 1 and 2 days after dropping with MIOI as 0.67, respectively. Therefore, CLIWELL$^{TM}$ was considered as non-irritating materials because the MIOI is detected below 5.00 throughout the whole experimental periods in both washing and non-washing groups and the IAOI was also detected as 4.50. Except for significant increase of the inflammatory cell ratios in ocular discharge at 1 day after dropping of non-washing group compared to that non-treated intact eyes, no meaningful changes on smear cytology of ocular discharges are observed in this study. In addition, no abnormal histopathological changes on the cornea, iris, retina and sclera were also detected in CLIWELL$^{TM}$ dropping group compared to that of non-treated intact eyes.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.189-195
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• 2002

The aim of this study was to investigate the action of benzalkonium chloride (BAC) used as a preservative in most ophthalmic topical solutions, on human corneal epithelial (HCE) cells in vitro. HCE cell line was exposed to BAC solutions at various concentrations (0.01%~0.0001%) for 15 minutes followed by 24 hours of cell recovery. Cell viability was assessed using MTT assay and chromatin condensation with a Hoechst 33342 test. The expression of membrane protein Fas and Fas ligand was examined by western blot and immunocytochemistry, and DNA fragmentation was studied by agarose gel electrophoresis. A significant decrease of membrane integrity with chromatin condensation was observed with BAC tested at concentrations of 0.005% and higher. BAC was cytotoxic preservatives in this study. An apoptotic mechanism appeared to be present at low concentrations of BAC, whereas a necrotic process appeared at higher concentrations. A functional Fas-mediated apoptotic pathway is present in cultured HCE cells and can be activated by upregulation of Fas expression with BAC.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.129-134
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• 2003

A wide variety of unsaturated vinyl derivatives can be induced to undergo free-radical chain polymerization. The capability to carry out a thermodynamically feasible polymerization relies on its kinetic feasibility on whether the proceeds at a reasonable rate under a given set of reaction conditions. Initiator or promoter is often required to achieve the kinetic feasibility. Only a few unsaturated monomers including methyl methacrylate(MMA) are known to absorb light between 250 and 500 nm which is the most convenient wavelength range. Also, the polysilanes with unusual optical and electronic properties have been used as ceramic precursors, deep UV photoresists, photoconductors. The hydrosilation has been used to make many interesting types of silicon containing polymers such as copolymer, dendrimers. Bulk polymerization of monomers with different molar radio of hydrosilanes(9:1 through 1:9) were performed. A quartz test tube charged with monomer and hydrosilane was degassed and irradiated with 250 nm UV for 6 hours. The polymer was taken in toluene, precipitated in hexane, filtered off, and dried. It was found that the initiators appeared to competitively and concurrently function as both chain initiation and transfer agents in the polymerization of vinyl monomers.

• Journal of Veterinary Clinics
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• v.20 no.2
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• pp.145-149
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• 2003

Color Doppler imaging(CDI) was carried out to determine CDI-derived resistive index(RI) values of normal canine ophthalmic vasculature and its reproducibility. CDI was performed on 58 dogs. and normal ranges of RI value were calculated for the medial long posterior ciliary artery(mLPCA), ciliary artery(CA), and ophthalmic artery(OA). Ophthalmic vascular RI values of normal dogs were 0.67$\pm$0.07, 0.70$\pm$0.06, and 0.80$\pm$0.04 in mLPCA, CA, and OA, respectively. Means of RT value of all vessel had no statistically significant difference by sex, fellow orbits, and skull type. The results suggest that color Doppler imaging is a noninvasive test which has the advantage of providing objective measurements of blood flow velocity parameter in the canine eye and orbit.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.109-114
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• 2008

Purpose: To assess the reproducibility and repeatability for each color vision test method. Methods: The subjects for color vision test were 30 students without congenital color vision deficiency and they major in optometry in a university, Korea. The type of color vision test selected for this study were Hans color vision test, Hans 15 hue test and Lanthony D 15 hue test. The Ishihara test was added for assessment of reliability of inter-tester. Results: All of the subjects were classified into normal at pseudoisochromatic plates, but one subject's result showed mild blue-yellow color deficiency at Hue discrimination. Results of 3 repeated test for subjects and inter-tester examination showed no errors at pseudoisochromatic plates. There were differences in mild errors among repeated test at Hue discrimination, but no differences were found in the results of repeated test to classify color vision deficiency. Conclusion: Each tester had better be more skilled to test even simple color vision test for eliminating the possibility of mild errors. Each subject might just as well be careful in color vision test. It is required to test both method of pseudoisochromatic plates and Hue discrimination in screening test.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.129-136
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• 1998

I obtained result like these to practice accommodation test using Spherical Add method and Cross cylinder lens method. The 242 eyes(121 persons) in test was the young and middle age people and their age was from 19 to 41. 1. Using Spherical Add, I tested accommodation. The twenties's limits of accommodation were 9~13 Diopter, and thirties to fourties's limits of accommodation were 6~8.5 Diopter. 2. Using Cross cylinder lens in the test of accommodation twenties's average accommodation limits were appeared 6.13 Diopter~10.13 Diopter, thirties average accommodation limits were 5.75 Diopter~8.75 Diopter and fourties's average accommodation limits were 4.38 Diopter~7.25 Diopter. All men women have had more good accommodation of the horizontal direction than the vertical direction. 3. Using Spherical Add method and Cross cylinder lens method, the results of accommodation were shown like these. Accommodation that measured with spherical add method was more big than cross cylinder's accommodation measuring method. Finally I found the fact accommodation decreases as age goes.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.1
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• pp.99-105
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• 2012

Purpose: The purpose of this study is to demonstrate inactivation effect of UVA-LED ultraviolet radiation upon Pseudomonas aeruginosa and Staphylococcus aureus which are the major bacteria causing eye diseases. Methods: The small sterilization device was made using UVA-LED of 400 nm. After Pseudomonas aeruginosa was diluted to $10^{-7}$ and Staphylococcus aureus to $10^{-5}$ and diluted solutions were put onto each liquid medium. They were irradiated by 400 nm of UVA for different amount of time; 15 min, 30 min, 60 min, 120 min, 240 min, 360 min and 480 min each. Results: The data from sterilization test was solved to regression line equation and the target log inactivation was obtained. The 3 log inactivation UV irradiation value of Pseudomonas aeruginosa was 54,847 UV dose ($mJ/cm^2$) and irradiation time was 135.42 min while the 3 log inactivation of Staphylococcus aureus was 39,066 UV dose ($mJ/cm^2$) and irradiation time was 98.72 min. Conclusions: The inactivation effect of sterilization method using 400 nm of UVA-LED upon Pseudomonas aeruginosa and Staphylococcus aureus has been verified and it is considered as a useful method in inactivating the contact lenses.