• Journal of Korean Ophthalmic Optics Society
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• v.15 no.3
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• pp.227-234
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• 2010

Purpose: The cleaning effect of protein deposit and the change of contact lens parameters by ultrasonic cleaner for eye glasses on the soft contact lenses were investigated. Methods: Etafilcon A contact lenses contaminated with protein, was ultrasonicated by ultrasonic cleaner for eye glasses and for the control group, spoiled contact lenses were cleaned by multi-purpose solution. The remaining protein deposits on the contact lenses were determined after extraction and the changes of overall diameter, base curve, center thickness power, and water contents on contact lenses were measured and surfaces of contact lenses were observed by scanning electron microscope. Results: The cleaning efficacies of multi-purpose solution on protein deposited etafilcon A contact lenses were 6.08%, and 23.73~33.92% in the group of ultrasonic cleaner for eye glasses with multi-purpose solution and 0~12.99% in the group of ultrasonic clear for contact lens with multipurpose solution depending on the treatment time. The changes of parameters and surface on contact lenses by ultrasonication were not observed. Conclusions: Ultrasonic cleaner for eye glasses can be used to eliminate protein deposits for the diagnostic soft contact lens in the office since it was effective to eliminate protein deposits and not caused change of parameters on soft contact lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.95-99
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• 2000

The microbial contamination rate of contact lens cases in multi-purpose solution(MPS) care systems of 80 asymptomatic soft contact lens wearers was investigated. In caring for their lenses 72 patients (90%) used chemical disinfection(include MPS), six patients(7%) used hydrogen peroxide, and two patients(3%) used heat. Fifty-nine percent of patients used MPS in their care systems. Of 80 contact lens cases, contamination was found in 68%(54) of cases. There is a significant relationship between the ages of lens cases and contamination: older cases being more frequently contaminated. Of the contaminated 31 lens cases(57%) in MPS care systems, four contact lens cases(13%) were contaminated by single organism, 15 cases(48%) by two kinds of organisms, and 12 cases(39%) by more than three kinds of organisms. Of the organisms that were contaminated lens cases, Pseudomonas. Serratia, Bacillus, E. coli and Aspergillus were frequently isolated. When considering the high contamination rate of soft contact lens cases in MPS care systems more effective and hygienical lens care system is important, especially frequent and regular disposal of lens cases may prove to prevent the build-up of microbial colonisation in containers.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.381-389
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• 2004

To investigate changes of multi-purpose solutions for soft contact lens(MPS) depending on using period or keeping temperature, we evaluate four brands of MPS. No significant difference was seen in protein deposit removing efficacy after samples had used for 24 weeks and kept at $4^{\circ}C$, $20^{\circ}C$ or $30^{\circ}C$. The pH values of the samples of 4 brands measured weekly over the 24 week testing period. The initial average pH value of samples were 7.0, 7.5, 7.6 or 8.2. One brand of MPS was in the range of the threshold for ocular awareness, which is outside the zone of 6.6 ~ 7.8. During the testing period, the pH value were decreased in using period-dependent manner. At the 24th week, the average pH values of samples turned to 6.6, 7.2, 7.2 or 7.7. However, the difference of keeping temperature was not associated with decreased levels of pH values. After 24 weeks, one of total 36 samples was contaminated by bacteria. Furthermore, the change of components was shown after 24 weeks in the analysis using thin layer chromatography and the analysis of UV absorption pattern. The results of our study provides that the keeping temperature of MPS is not the important factor of changes of MPS, but the using period of MPS can cause contact lens wearers discomfort.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.295-303
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• 2014

Purpose: This study aims to observe bleaching resulted from multipurpose contact lens solutions used to manage lenses with the subjects of colored contact lenses being distributed in Korea. Methods: The lenses have been worn for six months, and their refraction is 0.00D. Three types of colored contact lenses of which margin has been colored with a different manufacturing method have been adopted (type 1: pigment application method, type 2: chemical bonding process, type 3: sandwich method), and multipurpose solutions used were two types containing different components. Each of the colored contact lenses was stored in the multipurpose solutions for 20 days and went through vortexing for 15 seconds per day. Their fluorescence absorbance, surface roughness, brightness index, and color coordinate index were measured before and after the vortexing to see the degree of bleaching. Results: In the two types of multipurpose solutions, every type of the color contact lenses showed no statistically significant difference in their fluorescence absorbance value before and after the vortexing. Regarding surface image, the front surface of the lenses was smooth in every type, and about the back surface, type 3 indicated less protrusion than type 1 and 2. About the difference of color on the lens surface before and after the vortexing, type 3 showed significantly less difference than type 1 and 2; however, all fell into the permissible error. Conclusions: About the bleaching of colored contact lenses resulted from multipurpose solutions for soft contact lenses, there was no difference observed in terms of fluorescence absorbance and color. According to the methods of manufacturing dyes, however, there was difference in the protrusion of the posterior surface image.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.2
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• pp.135-145
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• 2011

Purpose: This study was conducted to investigate the actual condition of caring soft contact lens cases and the change in contamination level of lens cases by wearing and storage period of soft contact lens. Methods: The actual condition of caring soft lens cases was surveyed with sixty-three of contact lens wearers. Soft contact lenses were worn for 1, 3, 7 and 14 days, and the lenses were separately stored in 12 lens cases for 1, 3 and 7 days. The contamination level of lens cases was determined by counting the numbers of microorganisms, gram negative bacteria and fungi. Results: Only 14% of survey answerers cleaned their lens cases with a brush, rinsed and dried them upside down before next usage of lens case when those lenses were kept for a long time. Furthermore, 54% of total answerers just kept soft contact lens in the case without changing the multipurpose solution. Microorganisms, gram negative bacteria and fungi were detected in lens cases even when soft contact lens were kept for 1 day in the lens case after wearing for 1 day and cleaning it with multipurpose solution. The numbers of microorganisms, gram negative bacteria and fungi in lens cases increased with storage periods of soft contact lens, and also contamination level of lens cases was increased in accordance with wearing period of lens. In the lens cases without changing multipurpose solution, the numbers of microorganisms, gram negative bacteria and fungi increased with storage period of lens with statistical significance. Conclusions: This study showed that lens wearers' concerns on caring contact lens case were not satisfactory. As the result, the contamination of lens cases was related to increase of lens wearing and storage periods suggesting that the proper instruction and education for lens wearers are required.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.347-353
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• 2010

Purpose: An in vitro study was conducted to compare the lipid cleaning efficacy of care solutions on balafilcon A silicone hydrogel (SiHy) lens. Methods: Lipid spoilation was performed by incubating balafilcon A SiHy lenses in phosphate buffered saline (PBS) containing oleic acid, oleic acid methyl ester and cholesterol. Spoiled contact lenses rinsed with PBS were cleaned with surfactant cleaner, alcohol containing cleaner and multipurpose solution (MPS) respectively and repetitive spoilation and cleaning was conducted up to 14 times. To observe the cleaning effect of ultrasonic wave on the lipid deposit, each spoiled lens was ultrasonicated and then compared with non-sonicated lens. Lipids deposit on the contact lenses was extracted by methanol:chloroform (1:1, v/v) solution. High performance liquid chromatography was used to analyze and quantify lipid deposit extracts. Results: The effectiveness of alcohol containing surfactant cleaner on the lipid deposits was better than that of surfactant cleaner and MPS, and the cleaning efficacy was significantly higher in the ultrasonic wave treated group. Lipid deposits were not removed completely by contact lens care solutions so that lipid deposits increased continuously and cumulatively. Conclusions: The cleaning efficacy of contact lens care solutions was not satisfactory to remove lipid deposits on the SiHy lens that new cleaning products specially designed for SiHy lenses are needed to develop.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.1
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• pp.51-60
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• 2015

Purpose: To determine the effect of marketed multipurpose contact lens solutions (MPSs) on human corneal epithelial cells (HCEpiCs) toxicity by using image analysis. Methods: HCEpiCs were exposed six MPSs (product A-F) at 0.05~50% for 2h, 12h, 24h, and 48h respectively. HCEpiCs were fixed and stained with Draq5 after exposure with MPSs, and the cell viability and apoptosis were evaluated by using confocal microscope and ImageXpress UltraTM. Results: Viabilities of HCEpiCs exposed to MPS A-F for a 2h were not affected, while reductions (52~75%) in cell viability over a 12h exposure of MPS B, MPS C, MPS D and MPS F, and significant more reductions (29~73%) over a 24h and 48h-exposure. Apoptosis of HCEpiC was not affect over a 12h MPS exposure, however was significantly increased (199~526%) over 24h and 48h MPS exposure. Among the products MPS D, E and F reduced viability of HCEpiCs and apoptosis increased more than MPS A (p<0.05). Conclusions: Lower concentration of MPSs have not an cytotoxic effect on HCEpiCs, however higher concentration of MPSs induce apoptosis and reduce viability of HCEpiCs. Therefore, it need to develop MPS having antimicrobial effectiveness with low cytotoxicity.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.1
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• pp.15-20
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• 2002

The Hydroxyethyl methacrylate(HEMA) was developped in 1960's and later the use of contact lenses increased. At present more and more people use RGP contact lenses. Due to the wide range of optical corrections available and due to their high oxygen transmission Japanese and Korean people like them. Nevertheless one of nine CL users(beginners) stopped wearing the CL within the first year. We conducted a survey to evaluate the level of patient compliance in lens care and maintenance and to assess practitioner knowledge of contact lens information. Generally 6% of contact lens wearers drop out per year. The aim of this research was to find out what opticians can do to reduce the drop-out rate by getting information on handling, on general data of the patient and on optical prescription. Lens wearer were asked to complete a 10 question survey that focused on lens care-wear modality, lens replacement, storage, symptoms and case disinfection. There were total 180 participants in the study. Most of contact lens wearers have an inadequate understanding of contact lens care system. Therefore, it is important that contact lens specialists place more emphasis on practitioner education about general contact lens fields and reinforce patient education during the dispensing visit.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.53-68
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• 2004

Protein deposit buildup on soft contact lenses(SCLs) is responsible for discomfort, optical defects and is even damaging to the eye. To better understand protein deposit formation on SCL, we investigated the pattern of protein attachment on patient-worn SCLs and the effect of the protein on the contact angle of SCLs and the transmission of visible light. This study used data from a clinical trial where subjects wore either daily-wear SCL(etafilcon A, N=40) for various period up to 14 days, or extended-wear SCL(balafilcon A, N=40) for 8 h day or night. The adsorption of protein in daily-wear SCLs was significantly increased in patient-worn time-dependent manner although the lenses were cleaned everyday by using the multi-purpose SCL solution. After 2 weeks wearing, the protein on the SCL influenced the contact angle of the lenses. Furthermore, the transmission of visible light of the lenses decreased up to almost 7%. Extended-wear SCLs worn during the closed eye condition were found to deposit significantly more protein than SCLs worn during the open eye condition. The amounts of protein adsorbed both after daily SCL wear and after overnight SCL wear were not affected the contact angle and the transmission of visible light of the lenses. The protein deposit buildup on SCL related to the corneal temperature and pH of tear fluid.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.2
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• pp.179-188
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• 2014

Purpose: The present study was aimed to investigate the cleaning efficacy of multi-purpose solutions containing different types and content of surfactants and their effect on the visible light transmittance of soft lens. Methods: Soft lenses made of different materials (etafilcon A and hilafilcon B) were deposited tear proteins by using the artificial tear and then compared the resulting cleaning efficacy and visible light transmittance after cleaning the lens with 6 types of multi-purpose solutions containing different content of surfactants. Results: The cleaning efficacy of multi-purpose solutions was variously shown as approximately 23~43% according to the active concentration of surfactants and surface tension in multi-purpose solution when etafilcon A lens cleaned with rubbing. The highest cleaning efficacy was detected when cleaned with the multi-purpose solution containing hydrogen peroxide besides surfactant however, the amount of remaining protein was still high on the lens. After washed with multi-purpose solution, the visible light transmittance of lens was in 89.8 to 90.8%. The amount of protein deposited on hilafilcon B lens was very small compared with it on etafilcon A lens even though it was incubated in artificial tears for 7 days, which showed 5~10% of protein amount in etafilcon A lens and the decrease of visible light transmittance was also not significant. In case of rubbing with multi-purpose solution, the cleaning efficacy on hilafilcon B lens was in 45.4 to 67.4% however, the order of cleaning efficacy of multi-purpose solution was different from it on etafilcon A lens. The visible light transmittance of hilafilcon B lens has been restored to the level of new lens. Conclusions: From the result, it is concluded that the appropriate multi-purpose solution should be selected according to the lens material and the amount of protein deposit on the basis of understanding surfactants and active principle for proper care of protein deposit on soft lens and the cleaning with rubbing is more efficient for lens care regardless of manufacturer's guideline.