• Title/Summary/Keyword: UV-A blocking contact lens

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Denaturation and Inactivation of Antioxidative Enzymes due to Repeated Exposure to UV-B and Inhibitory Effect of RGP Lens (UV-B 반복노출에 따른 항산화효소의 변성 및 활성저하와 RGP렌즈의 차단효과)

  • Byun, Hyun Young;Lee, Eun Jung;Oh, Dae Hwan;Kim, So Ra;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.2
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    • pp.237-246
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    • 2015
  • Purpose: The present study was conducted to reveal the correlation of structural denaturation and decrease of enzyme activity when the antioxidative enzymes, superoxide dismutase (SOD) and catalase (CAT) were repeatedly exposed to UV-B, and further investigate whether the denaturation and inactivation of those enzymes can be effectively blocked by using UV-inhibitory RGP lens. Methods: Each enzyme solution was prepared from the standardized SOD and CAT, and repeatedly exposed to UV-B of 312 nm for 30 minutes, 1 hour and 2 hours a day over 1, 2, 3, 4 and 5 days. Structural denaturation of SOD and CAT induced by repeat UV-B irradiation was confirmed by the electrophoretic analysis, and their enzyme activity was determined by the colorimetric assay using the proper assay kit. At that time, the change in structure and activity of the antioxidant enzymes directly exposed to UV-B was compared to the case that UV-B was blocked by UV-inhibitory RGP lens. Results: SOD exposed repeatedly to UV-B showed the polymerization pattern in the electrophoretic analysis when it repeatedly exposed for 30 min a day, however, the change of its activity was less than 10%. On the other hand, CAT repeatedly exposed to UV-B reduced size and density of the electrophoretic band which indicated a structure denaturation, and its activity was significantly decreased. In the case that the repeat exposure time was longer, CAT activity was completely lost even though some enzyme band occurred in the electrphoretic analysis. In addition, the degeneration of CAT due to UV-B irradiation was inhibited to some extent by using RGP lens with a UV-B blocking of 63.7%, however, it was not completely inhibited. Conclusions: From these results, it was revealed that the structural denaturation of antioxidative enzymes was not perfectly correlated with the reduction in enzyme activity according to the type of enzyme. It is recommended to minimize the exposure time to UV when wearing contact lens, or wear the contact lenses having UV blocking rate of the FDA Class I blocker or the sunglasses having equivalent UV-blocking rate for reducing the damage of antioxidative enzymes induced by UV.

Opto-Physical Properties of Ophthalmic Lens Polymer Containing σ, m, p-Substituted Difluoroaniline as Additives (σ, m, p-위치로 치환된 Difluoroaniline을 첨가제로 사용한 안의료용 렌즈 고분자의 물리·광학적 특성)

  • No, Jung-Won;Sung, A-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.1
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    • pp.69-77
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    • 2014
  • Purpose: The functional ophthalmic lenses containing fluorine-substituted aniline group (2,4-difluoroaniline, 2,6-difluoroaniline, 3,4-difluoroaniline) were manufactured and the physical and optical characteristics of copolymerized ophthalmic lens were investigated. Methods: HEMA (2-hydroxyethylmethacrylate), NVP (N-vinyl pyrrolidone), MA (methacrylic acid), the cross-linker EGDMA (ethylene glycol dimethacrylate) and the initiator AIBN (azobisisobutyronitrile) were used as a basic combination and fluorine-substituted aniline group (2,4-difluoroaniline, 2,6-difluoroaniline, 3,4-difluoroaniline) were used as additives for preparing the hydrogel soft contact lenses. The hydrogel ophthalmic lens was manufactured by cast mould method and the ophthalmic lenses were stored in a 0.9% NaCl normal saline for 24 hrs. Results: The optical transmittance of the sample with addition 2,4-difluoroaniline showed that the UV-B(9.8~51.4%), UV-A(58.8~79.2%) and visible transmittance(87.0~90.4%). In the case of 2,6-difluoroaniline were measured the UV-B(80.2~83.2%), UV-A(85.8~86.4%), and visible transmittance(90.8~91.4%). Also, the optical transmittance of ophthalmic lens containing 3,4-difluoroaniline were measured the UV-B transmittance of 3.8~30.4%, UV-A transmittance of 47.8%~74.4% and the visible transmittance of 86.2~91.0% respectively. Conclusions: Based on the results of this study, 2,4-difluoroaniline and 3,4-difluoroaniline can be used effectively as additive for UV-blocking ophthalmic contact lenses.

Change of Physical Properties of Hydrogel Lens Polymer Containing Isocyanate Group with Ag Nanoparticle

  • Cho, Seon-Ahr;Sung, A-Young
    • Journal of Integrative Natural Science
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    • v.7 no.1
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    • pp.5-10
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    • 2014
  • A study that copolymerized Ag nanoparticle and furfuryl isocyanate with the crosslinking agent EGDMA (ethylene glycol dimethacrylate), HEMA (2-hydroxyethyl methacrylate), MMA (methyl methacrylate), MA (methacrylic acid) and the initiating agent AIBN (azobisisobutyronitrile) is presented. Measurement of the physical characteristics of the produced macromolecule showed that the water content is 32.08~32.67%, refractive index 1.446~1.448, visible light transparency 83.2~67.6%, contact angle $68.2{\sim}83.5^{\circ}$ and tensile strength 0.541~0.755 kgf. It is also demonstrated that the addition of Ag nanoparticles is associated with the reduction of UV-B transmittance and increase in tensile strength. The results show that the produced copolymer can be used as a material for ophthalmic lenses with durability and UV-blocking properties.

The Corneal Effects Induced by Ultraviolet Radiation (자외선에 의한 각막의 영향)

  • Kim, Douk Hoon
    • Journal of Korean Ophthalmic Optics Society
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    • v.7 no.2
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    • pp.229-234
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    • 2002
  • The human eye and skin is exposed daily to solar energy. Expecially, the ultraviolet radiation (UVR) exposure has been damaged as an important causative factor in corneal disease. These damage of cornea was effected the retina. Therefore the eye function was effected very significant damage. As a results the protect of UVR in the eye is very important in ocular health. Therefore in living the intensive ultraviolet radiation environment by solar energy, human eye have protected the cornea and eyeball by the UV-blocking sunglass, eyeglass, goggles, and contact lens. Finally the specific UV-blocker lens devices available to the primary care for the subjects by optician. Of course, in the future these specific lenses have to development and study by fellowship.

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