• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.81-91
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• 2004

The use of soft contact lenses for myopia correction is increasing in many countries. It is therefore important for contact lens practitioners to be properly educated in fitting these lenses. Before fitting lenses, it is important to consider the factors and procedures related to soft contact lens fitting, indications and contraindications of fitting soft contact lenses. In this article, the functions and activities involved in preliminary, fitting and delivery consultations will be presented.

• Journal of Korean Clinical Health Science
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• v.7 no.1
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• pp.1205-1214
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• 2019

Purpose: To investigate the effect of color soft contact lenses on the corneal thickness in young Korean population. Methods: The subjects consisted of 112 eyes (7 males, 49 females) with the mean age of $20.987{\pm}1.093years$ (range 20-25 years) in young Korean population during 2018. Test was compared the corneal thickness before and after wearing color soft contact lenses. The thinnest cornea thickness(TCT), central cornea thickness(CCT), pupil centre thickness(PCT), superior corneal thickness(SCT),inferior corneal thickness(ICT), medial corneal thickness(MCT), lateral corneal thickness(LCT) of the cornea was measured using the Pentacam pachymetry. The statistically analysis was perform the Shaparo-Wilk test. Results: The right eye was a statistically significant among the CCT,LCT, MCT and TCT values(p<0.001) in the compared the corneal thickness before and after wearing soft colour contact lenses. Also the left eye was a statistically significant among the LCT and MCT values(p<0.001) in the compared the corneal thickness before and after wearing soft colour contact lenses. However, there was no statistical difference (p>0.5) in the mean PCT between before and after wearing color soft contact lenses. Conclusion: These results suggested that the color soft contact lens wear can the effect the regional thickness of cornea. Therefore, the analysis of corneal topography with Pentacam can provide correct and useful diagnostic information of the morphology of the RGP contact lens fitting and diagnosis of corneal refraction surgery.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.313-321
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• 2005

To know the pollution level concerning the microbes contamination condition in soft contact lenses, 2 experiments were operated with different methods. Firs experiment, we observed lenses surfaces through a scanning electronic microscope after pollution sort contact lenses with the suspensions of Staphylococcus aureus, Pseudomonas aeruginosa and Entrobacter aerogenes which can be major bacteria causing keratitis as wearing on soft contact lenses. As 1 hour after pollution with the soft contact lenses, we observed that many bacteria adhered to the lenses, and the pollution condition got worse with passing time increase(2, 4, 6, 12, and 24 hours, respectively). At 12 hours lapse of polluting soft contact lenses with P. aeruginosa, some bacteria adhered to the lenses. And as 24 hours lapsed after pollution soft lenses with E. aerogenes, bacteria adhered to them, and atypical substance was observed some of the surface of lenses. Second experiment, we observed the microbe pollution condition in soft contact lenses by let 21 people in twenties(men & women), who doesn't eye disorders, wear soft contact lenses during 4 hours. As the result, many kinds of bacterium and fungus were observed, and especially, the bacteria could be identified with their colors and the shapes of colony, so we found that single type, two types, and three types of bacteria adhered to their lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.39-45
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• 2009

Purpose: The purpose of this study is to compare the visual performance by contrast sensitivity (CS) and disability glare (DG) in low astigmatic eyes corrected with toric soft lenses and other optical corrections. Methods: Twenty university students with myopia (-1.00 to -6.50D Sph. with astigmatism up to 1.50 cyl) were enrolled and corrected by five different methods: 1) soft toric lenses; 2) spherical soft contact lenses; 3) RGP lenses; 4) best spectacle corrected visual acuity; 5) spherical equivalent spectacles. All subjects had corrected vision acuity of 20/20 or better. Contrast sensitivity and disability glare were measured using the OPTEC 6500 contrast sensitivity view-in tester included the EyeView Functional Vision Analysis software at photopic or mesopic conditions with glare. Results: At photopic condition, best corrected spectacle wearers had the highest monocular contrast sensitivity at all spatial frequency followed by soft toric lenses, RGP lenses, spherical equivalent spectacles, and spherical soft contact lenses. However, all of them were in normal contrast sensitivity value at photopic condition. At mesopic condition with glare, toric soft lenses were the highest and followed by RGP lenses, spherical equivalent spectacles, best spectacle corrected visual acuity and spherical soft contact lenses. It was observed that spherical soft contact lens wearers demonstrated lower range than normal contrast sensitivity value at mesopic condition with glare. Conclusion: Toric soft lenses gave better visual performance than spherical soft lenses in low astigmatic eyes. Subjects requiring the use of contact lenses under mesophic conditions could benefit from toric soft lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.3
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• pp.165-171
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• 2005

The aim of the study was to investigate the diameter and base curve changes of soft contact lens by protein deposition. Soft contact lenses were soaked in artificial tear or protein solution which had the same composition with tear for 2min, 10min, 30min, 1hr, 3hr, 6hr, 12hr, and 24hr. Diameter and base curve changes of soft contact lenses were examined by using the high speed camera(Fastcam ultima 1024). The longer the soaking time of soft contact lenses in the artificial tear, the diameter and base curve changes of soft contact lenses was more increased. In the case of soft contact lenses adsorbed only protein, the similar pattern was shown and the diameter and base curve were decreased. However, the influence of calcium ion was found to be less than that of protein. These results suggest that the tear protein causes the diameter and base curve decrease of soft contact lens, which might be related to the discomfort after soft contact lens wearing.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.3
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• pp.215-225
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• 2016

Purpose: The aim of this study was to figure out how the characteristics of soft contact lens materials and pigmentation affect the adherence of C. albicans on soft contact lenses pre-deposited with tear constituents. Methods: The adherent number of C. albicans on clear soft contact lenses (hereinafter clear lenses) and circle soft contact lenses (hereinafter circle lenses) made of etafilcon A, hilaiflcon B and nelfilcon A, respectively, was measured before and after the deposition of artificial tear. Also, bacteria adherence on lenses were observed by a scanning electron microscope. Results: Adherence of C. albicans was significantly different according to lens materials. The amount of adsorption was not different between clear lenses and circle lenses made of etafilcon A however, the number of bacteria absorption was bigger in hilafilcon B and nelfilcon A lenses. More absorption of C. albicans was found in the non-pigmented central area compared the pigmented area, and non-pigmented peripheral area has more bacterial absorption than non-pigmented central area. The number of C. albicans decreased in the case that tear protein was pre-deposited. The maintenance of antibacterial activity against C. albicans was different according to lens materials thus, etafilcon A has the longest period of its maintenance. Conclusions: It was revealed that the number of C. albicans was different according to the characteristics of lens materials, pigmentation or non-pigmentation, the pigmented area of soft contact lenses. Thus, it is suggested that the management method should be different according to the adsorption characteristics of C. albicans.

• Journal of Life Science
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• v.19 no.4
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• pp.538-542
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• 2009

In this study, we confirmed water content and oxygen permeability of new polymeric materials synthesized from itaconic acid used for soft contact lenses. In this study, we polymerized materials for soft contact lenses using HEMA (2-hydroxyethyl methacrylate), the based-monomer of soft contact lenses, EGDMA (ethylene glycol dimethacrylate) as a cross linkage agent, and the new additives mono-ester or di-ester derived from itaconic acid commercially produced by the fermentation of A. itaconicus. New polymer materials for contact lenses were synthesized with the mixture of HEMA and mono- or di-ester at different ratios and water content and oxygen permeability (Dk) was analyzed. In polymerizing HEMA and mono-ester (15%), the water content and oxygen permeability of contact lenses were found to be of good value at 57.7% and 28.6 Dk respectively. The mixture of HEMA and mono-ester is more excellent than HEMA/di-ester in regards to water content and oxygen permeability. The water content and oxygen permeability of soft contact lenses made by new polymeric materials were highly represented.

• 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.12 no.4
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• pp.119-125
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• 2007

The aim of the present study was to compare the contrast sensitivity of soft contact lens wearers, spectacle wearers or emmetropia. Seventy myopic eyes and thirty emmetropic eyes aged 19 to 26 years were collected. The myopic group included 48 eyes corrected with spectacle lenses and 22 eyes of them corrected with contact lenses, too: all had corrected vision acuity of 20/20 or better. Spatial contrast sensitivity was measured using the OPTEC 6500 contrast sensitivity view-in tester included the EyeView　 Functional Vision Analysis software at photopic or mesoopic condition. There was no significant difference in contrast sensitivity between spectacle lenses and emmetropes. Myopes corrected with soft contact lenses showed statistical sensitivity losses at 1.5, 12 cycle/degree spatial frequencies. In conclusion, our findings suggest that loss of contrast sensitivity in soft contact lens wearers might be interpreted as evidence for corneal disruption before corneal pathological events occur in contact lens wearers. Contrast sensitivity testing appears to be a useful method for evaluating soft contact lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.2
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• pp.37-45
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• 2007

We have measured the spectral transmittances of UV blocking soft contact lenses, regular soft contact lenses and regular RGP lenses using the method suggested in ANSI Z80.20 standard. In order to evaluate visible light transmitting and UV blocking characteristics, we have calculated transmittances by integrating over the specific spectral ranges, i.e., visible light, UVA, UVB and UVC. We found that mean transmittances of visible light for all three categories were over 90.0 % which could be considered as within acceptable range for a contact lens. The transmittance of the UVA and UVB radiation for the UV blocking soft lenses except some cases was within UVR (Ultraviolet radiation) transmittance standard. The UV blocking ability of regular soft and RGP lenses was poor as rather expected. These results will be expected to assist clinical opticians and practitioners in utilizing the transmittance characteristics about the contact lens.