A single-lens polarographic measurement of oxygen permeability (Dk) for hypertransmissible soft contact lenses

Biomaterials ◽  
2007 ◽  
Vol 28 (30) ◽  
pp. 4331-4342 ◽  
Author(s):  
M CHHABRA ◽  
J PRAUSNITZ ◽  
C RADKE
Keyword(s):  
Oxygen Permeability ◽  
Contact Lenses ◽  
Soft Contact ◽  
Soft Contact Lenses ◽  
Single Lens ◽  
Polarographic Measurement

scholarly journals Refractive behavior changes with six months daily wear of high and low oxygen permeability hydrogel contact lenses

2006 ◽  
Vol 65 (2) ◽  
Author(s):  
W.D.H. Gillan
Keyword(s):  
Oxygen Permeability ◽  
Contact Lenses ◽  
The Other ◽  
Behavior Changes ◽  
Low Oxygen ◽  
Soft Contact ◽  
Silicone Hydrogel ◽  
Refractive State ◽  
Soft Contact Lenses ◽  
Silicone Hydrogels

Introduction: The investigation of myopia and soft contact lenses is not new. Many reports show  that  the  wearing  of  silicone  hydrogel lenses as opposed to conventional disposable hydrogel lenses results in little progression of myopia in the eyes wearing silicone hydrogels. Method: Six subjects wore a silicone hydro-gel lens on one eye while the other eye wore a habitual disposable hydrogel lens for six months of daily wear. Fifty measurements of refractive state in each eye were taken prior to the subjects wearing a silicone lens in one eye and a conven-tional hydrogel lens in the other eye. After six months of daily wear another fifty measurements of refractive state were taken for each subject. Results:  Although  there  is  no  statisti-cal  support  for  the  findings  of  this  study, comet stereo-pairs are used to show the chang-es in refractive state for each subject. Four of  the  six  subjects  showed  an  increase  in myopia in the eye wearing the silicone lens. Discussion:  The  increase  in  myopia in eyes wearing a silicone hydrogel lens is contrary  to  the  findings  of  other  studies.

scholarly journals Influence of Tear Protein Deposition on the Oxygen Permeability of Soft Contact Lenses

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Se Eun Lee ◽  
So Ra Kim ◽  
Mijung Park
Keyword(s):  
Oxygen Permeability ◽  
Contact Lenses ◽  
Boundary Effect ◽  
Soft Contact ◽  
Silicone Hydrogel ◽  
Artificial Tear ◽  
Protein Deposition ◽  
Soft Contact Lenses ◽  
Tear Proteins ◽  
Tear Protein

Purpose. To investigate the effect of tear protein deposition on the change in oxygen permeability (Dk) of soft contact lenses (SCL). Methods. Three hydrogel lenses (polymacon, nelfilcon A, and etafilcon A) and two silicon hydrogel lenses (lotrafilcon A and balafilcon A) were investigated. Etafilcon A lenses were incubated in artificial tear solution for 1, 6, 12, and 48 h, whereas the other SCL were incubated for 1, 3, 7, and 14 days. Oxygen permeability was measured using the polarographic method, and lenses were stacked in four layers to correct the boundary effect. Results. The Dk of all investigated SCL was decreased by the protein deposition. Silicone hydrogel lenses showed a smaller deposition of artificial tear proteins than conventional hydrogel lenses. However, their Dk was reduced twofold than those of 3 conventional hydrogel lenses when compared at the same level of protein deposition. Despite a large amount of total deposited protein in etafilcon A lenses, their Dk was more stable than other SCL. Conclusions. From the results, it was revealed that the Dk of SCL is different from the value provided by manufacturers because of the tear protein deposition on surface and/or in pore of SCL; however, the degree of Dk change in SCL was not simply correlated with the amount of tear protein deposition. Thus, it is considered that the correlation between tear protein deposition and properties of lens materials affects Dk change.

Oxygen Permeability of Disposable Soft Contact Lenses

1990 ◽  
Vol 110 (3) ◽  
pp. 269-273 ◽  
Author(s):  
Barry A. Weissman ◽  
Steven D. Schwartz ◽  
Nina Gottschalk-Katsev ◽  
David A. Lee
Keyword(s):  
Oxygen Permeability ◽  
Contact Lenses ◽  
Soft Contact ◽  
Soft Contact Lenses

scholarly journals A Novel Approach to Increase the Oxygen Permeability of Soft Contact Lenses by Incorporating Silica Sol

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2087
Author(s):  
Nguyen-Phuong-Dung Tran ◽  
Chuan-Cheng Ting ◽  
Chien-Hong Lin ◽  
Ming-Chien Yang
Keyword(s):  
Contact Angle ◽  
Oxygen Permeability ◽  
Contact Lenses ◽  
Optical Transmittance ◽  
Silica Content ◽  
Silica Sol ◽  
Soft Contact ◽  
Soft Contact Lenses ◽  
Young’S Moduli ◽  
Novel Approach

This study presents a novel approach to increase the oxygen permeability of hydrogel by the addition of silica sol. Herein, 2-hydroxyethyl methacrylate (HEMA) was copolymerized with N-vinyl-2-pyrrolidone (NVP) after mixing with silica sol. The resultant hydrogel was subject to characterizations including Fourier-transform infrared (FTIR), equilibrium water content (EWC), contact angle, optical transmittance, oxygen permeability (Dk), tensile test, anti-deposition of proteins, and cytotoxicity. The results showed that with the increase of silica content, the Dk values and Young’s moduli increased, the optical transmittance decreased slightly, whereas the EWC and contact angle, and protein deposition were not much affected. Moreover, the cytotoxicity of the resultant poly(HEMA-co-NVP)-SNPs indicated that the presence of silica sol was non-toxic and caused no effect to the growth of L929 cells. Thus, this approach increased the Dk of soft contact lenses without affecting their hydrophilicity.

Peculiarities of cultivation of the monolayer of fetal fibroblasts on the soft contact lenses, with contain the collagen

2009 ◽  
Vol 21 (5) ◽  
pp. 46-50
Author(s):  
N. Pasechnikova ◽  
◽  
G. Drozhzhina ◽  
O. Ivanova ◽  
I. Nasinnik ◽  
...  
Keyword(s):  
Contact Lenses ◽  
Soft Contact ◽  
Soft Contact Lenses ◽  
Fetal Fibroblasts

Modification of therapeutic silicone-hydrogel soft contact lenses

2016 ◽  
Vol 16 (3) ◽  
pp. 117-120 ◽  
Author(s):  
T.N. Safonova ◽  
◽  
I.A. Novikov ◽  
V.I. Boev ◽  
O.V. Gladkova ◽  
...  
Keyword(s):  
Contact Lenses ◽  
Soft Contact ◽  
Silicone Hydrogel ◽  
Soft Contact Lenses

scholarly journals Myopia Control with Combination Low-Dose Atropine and Peripheral Defocus Soft Contact Lenses: A Case Series

2021 ◽  
pp. 548-554
Author(s):  
Nir Erdinest ◽  
Naomi London ◽  
Nadav Levinger ◽  
Yair Morad
Keyword(s):  
Low Dose ◽  
Contact Lenses ◽  
Case Series ◽  
Concentric Circle ◽  
Retrospective Case ◽  
Soft Contact ◽  
Myopia Progression ◽  
Soft Contact Lenses ◽  
Center Distance ◽  
Myopia Control

The goal of this retrospective case series is to demonstrate the effectivity of combination low-dose atropine therapy with peripheral defocus, double concentric circle design with a center distance soft contact lenses at controlling myopia progression over 1 year of treatment. Included in this series are 3 female children aged 8–10 years with progressing myopia averaging −4.37 ± 0.88 D at the beginning of treatment. Their average annual myopic progression during the 3 years prior to therapy was 1.12 ± 0.75 D. They had not attempted any myopia control treatments prior to this therapy. The children were treated with a combination of 0.01% atropine therapy with spherical peripheral defocus daily replacement soft lenses MiSight<sup>®</sup> 1 day (Cooper Vision, Phoenix, AZ, USA). They underwent cycloplegic refraction, and a slit-lamp evaluation every 6 months which confirmed no adverse reactions or staining was present. Each of the 3 children exhibited an average of 0.25 ± 0.25 D of myopia progression at the end of 1 year of treatment. To the best of the authors’ knowledge, this is the first published study exhibiting that combining low-dose atropine and peripheral defocus soft contact lenses is effective at controlling children’s moderate to severe myopia progression during 1 year of therapy.

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