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 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.

Effect of the medicine “Cationorm” on lacrimal film in obstructive dysfunction of meibomyus glands among users of soft contact lenses

2020 ◽  
pp. 39-45
Author(s):  
Ekaterina B. GORSHENYOVA ◽  
Nataliya M. SUTORMINA
Keyword(s):  
Hyaluronic Acid ◽  
Contact Lenses ◽  
Control Group ◽  
Delayed Effect ◽  
Soft Contact ◽  
Silicone Hydrogel ◽  
Soft Contact Lenses ◽  
Pathogenetic Therapy ◽  
Tear Substitute

There are more than 80 million users of soft contact lenses in the world - 10-15 % of the population. The prevalence of meibomyus gland dysfunction is 43-61 % with the prevalence of obstructive form and the development of lipodeficiency in lacrimal film. At the same time, the use of traditional tear substitutes based on hyaluronic acid is ineffective and the problem of finding a tear substitute with exposure to all 3 layers of lacrimal film becomes relevant. Nanoemulsion “Cationorm” is created as a means of pathogenetic therapy of dry eye syndrome against the background of lipodeficiency, however, there weren't any studies of its effectiveness in obstructive form of meibomyus gland dysfunction among users of soft contact lenses. We examined 3 layers of lacrimal film with the help of Norn's sample with determination of time of lacrimal film break, bio-measurement of lacrimal meniscus and biomicoscopy of eyelid edge region at painting of lissamino-om green. The study involved 28 young carriers of silicone-hydrogel contact lenses with signs of obstructive form of meibomyus gland dysfunction, who we divided into two groups: a control group used to eliminate the symptoms of a hyaluronic acid-based tear substitute, and an experimental group using the drug “Cationorm”. We revealed prolonged effect of nanoemulsion “Cationorm” on all three layers of lacrimal film, which hasn't only symptom lacrimal, but has pathogenetic therapeutic delayed effect among users of soft contact lenses with obstructive form of dysfunction of meibomyum glands, and nanostimer of lipid microspheres provides full compatibility even with material of silicone-hydrogel soft contact lenses. We proved the protective effect of the preparation on ocular epithelium cells.

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.

scholarly journals Bacterial adhesion to Conventional and Silicone hydrogel contact lenses

2021 ◽  
Vol 23 (1) ◽  
pp. 25-35
Author(s):  
Eghosasere Iyamu ◽  
Frederick Osaro Ekhaise
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Contact Lens ◽  
Bacterial Adhesion ◽  
Contact Lenses ◽  
Bacterial Species ◽  
Soft Contact ◽  
Silicone Hydrogel ◽  
Soft Contact Lenses ◽  
Lens Wear

Purpose: The aim of this study was to investigate the adhesion of bacteria to worn silicone hydrogel and conventional soft contact lenses.Methods: Bacterial adhesion experiments / assays were performed on 24 worn and 6 unworn soft contact lenses each of different materials (high- and low- gas permeable lenses) using the strains such as Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923.Results: P. aeruginosa adhered in increased number to worn than unworn Lotrafilcon A and conventional lenses. However, a higher number of P. aeruginosa adhered to unworn than worn Lotrafilcon B, the difference in the mean adhesion was not significant (p = 0.66). S. aureus adhered in significantly decreased number to worn Lotrafilcon A, nelfilcon A, nesofilcon A, etafilcon A and omafilcon A (p<0.05); butsignificantly higher number adhered to worn than unworn polymacon (p<0.05). Lens wear had no effect on the adhesion of S. aureus to Lotrafilcon B (p>0.05). The least adhesion of P. aeruginosa to worn contact lenses was seen with polymacon, while S. aureus adhered in least number to worn Lotrafilcon A compared to the other contact lens materials that demonstrated the same trend in adhesion.Conclusion: The higher adhesion of P. aeruginosa to worn lenses is consistent with the claim that it is the most implicated in all culture-positive contact lens related bacterial keratitis. Lens wear has different effects on bacterial adhesion, which may be due to type of lens materials and bacterial species/genera studied. Keywords: Silicone hydrogel lenses, conventional lenses, Pseudomonas aeruginosa, Staphylococcus aureus, bacterial adhesion.

scholarly journals The impact of silicone hydrogel contact lenses on the measurement of intraocular pressure using non-contact tonometry

2017 ◽  
Vol 74 (8) ◽  
pp. 763-766 ◽  
Author(s):  
Snezana Pesic ◽  
Svetlana Jovanovic ◽  
Milos Mitrasevic ◽  
Biljana Vuletic ◽  
Milena Jovanovic ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Contact Lenses ◽  
Accurate Method ◽  
Contact Method ◽  
Soft Contact ◽  
Silicone Hydrogel ◽  
Soft Contact Lenses ◽  
Significant Difference ◽  
The Impact ◽  
Noncontact Tonometry

Background/Aim. Measurement of intraocular pressure (IOP) over therapeutic silicone hydrogel soft contact lenses by a non-contact method of tonometry could be applied in opthalmologic practice but the results obtained are still controversial. The aim of this study was to evaluate the effect of spherically designed silicone hydrogel soft contact lenses and their power on values of IOP measured by using a noncontact tonometry method. Methods. We measured IOP with and without spherical silicone hydrogel soft contact lenses on 143 eyes of 80 subjects who did not have any ocular or systemic diseases. Results. The Wilcoxon statistical analysis test for ranking average values of IOP measured on 143 eyes over a spherical silicone hydrogel soft contact lenses showed significantly higher values compared to those measured with no contact lenses (15.81 ? 3.46 mm Hg vs 14.54 ? 3.19 mm Hg; respectively; Z = -5.224, p = 0.001). Refractive power analysis of the contact lenses of -9.00D to +6.00 D showed a significant difference of IOP in the range from 0.00D to -6.00D. Conclusion. Non-contact tonometry is not an accurate method of IOP measuring over spherical silicone hydrogel soft contact lenses which belong to therapeutic contact lenses.

scholarly journals Evaluation of Pollen Adhesion to Verofilcon-A Soft Contact Lenses

2021 ◽  
Vol 15 (1) ◽  
pp. 305-313
Author(s):  
Tatsuya Mimura ◽  
Hiroshi Fujishima ◽  
Eichi Uchio ◽  
Kazumi Fukagawa ◽  
Yuji Inoue ◽  
...  
Keyword(s):  
Contact Lenses ◽  
Pollen Grains ◽  
Soft Contact ◽  
Silicone Hydrogel ◽  
Soft Contact Lenses ◽  
Soft Contact Lens ◽  
Different Types ◽  
Protein Components ◽  
Cedar Pollen ◽  
Number Of Particles

Purpose: A new 1-day disposable soft contact lens (SCL), verofilcon-A, constructed of silicone hydrogel material, has recently become available in Japan. This SCL has a very smooth surface produced by using the SMARTSURFACE ® Technology, and it was expected that pollen particles and protein components would not adhere easily to its surface. We examined the degree of pollen adhesion to the surface of the verofilcon-A material SCL and compared the results with those of other 1-day disposable SCLs (1DSCL). Methods: To determine the number of pollen grains attached to the surface of different types of SCLs, 0.01 mg/ml of cedar pollen solution was dropped onto the surface of 13 types of 1DSCL. After 24 h, each 1DSCL was rinsed in a shaker and washed five times with saline (n = 10 for each 1DSCL type). The number of pollen particles adhered to the 1DSCL and the percentage of surface area occupied by pollen was determined. Results: The number of pollen particles on the 1DSCLs ranged from 0 to 185 in the 200 × 200 µm area. The number of particles was lowest in the delefilcon-A and verofilcon-A SCLs with 0 particles, and the number was higher in the other 11 1DSCLs. The number of pollen particles was negatively correlated with the water content (r = −0.48), oxygen permeability (Dk; r = −0.43), oxygen transmissibility (r = −0.42), and center thickness (r = −0.33) of the 1DSCLs. The pollen adhesion area ranged from 0.0% to 3.1% and was lowest in the delefilcon-A and verofilcon-A 1DSCLs. There were significant differences in the pollen adhesion area between colored 1DSCLs (2.73 ± 1.97%) and clear 1DSCLs (1.03 ± 1.01%, P<0.001) and between hydroxyethyl methacrylate-based 1DSCLs (1.84 ± 1.45%) and silicone hydrogel-based 1DSCLs (0.05 ± 0.16%, P<0.001). Conclusion: These findings indicate that the verofilcon-A 1DSCL processed with SMARTSURFACE™ Technology is an excellent option for SCL users with allergic conjunctivitis during the high pollen season.

Comparison of Silicone and Non-silicone Hydrogel Soft Contact Lenses Used as a Bandage After LASEK

2008 ◽  
Vol 24 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Raquel Gil-Cazorla ◽  
Esther Arranz-Márquez ◽  
Miguel A Teus
Keyword(s):  
Contact Lenses ◽  
Soft Contact ◽  
Silicone Hydrogel ◽  
Soft Contact Lenses
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