scholarly journals Change in the geometry of positive- and negative-powered soft contact lenses during wear

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242095
Author(s):  
Bartlomiej J. Kaluzny ◽  
Joanna Stachura ◽  
Patryk Mlyniuk ◽  
Alfonso Jimenez-Villar ◽  
Magdalena Wietlicka-Piszcz ◽  
...  
Keyword(s):  
Contact Lenses ◽  
Specular Microscopy ◽  
Soft Contact ◽  
Swept Source ◽  
Contact Lens Wear ◽  
Soft Contact Lenses ◽  
Epithelial Thickness ◽  
Custom Made ◽  
Lens Wear

Contact lens wear causes mutual interactions between the ocular surface and the lens, which may affect comfort as well as vision. The aim of this study was to examine deformations in modern positive- and negative-powered silicone hydrogel soft contact lenses (SiH SCLs) after 7 days of continuous wear. This pre-post interventional study included 64 eyes: 42 eyes with myopia of -3.00 D and 22 eyes with hyperopia of +3.00 D. All patients underwent general ophthalmic examination, corneal topography/tomography, total corneal and epithelial thickness mapping, and specular microscopy before and after the wearing period. SiH SCLs made of senofilcon A were worn continuously for 7 days on all eligible eyes. The geometry of the new and used lenses was measured 3 to 6 minutes after removal in two perpendicular planes using a custom-made swept source optical coherence tomography (SS-OCT) system for in vitro measurements. The anterior and posterior radii of curvature decreased in -3.00 D lenses in two perpendicular planes. This effect correlated significantly with average keratometry of the cornea. Sagittal lens height was lower in +3.00 D lens after wear, which correlated moderately with the corneal sagittal height. A significant decrease in central corneal epithelial thickness was observed after wearing +3.0 D lenses. In conclusion, SiH SCLs made of senofilcon A undergo minor deformations after 7-day continuous wear. Geometry modifications are different for -3.00 D and +3.00 D lenses, and they imitate the shape of the anterior eye surface. These geometric changes are accompanied by a decrease in the central thickness of corneal epithelium after +3.00 D lens wear.

scholarly journals Pigmentation of the Cornea Secondary to Tinted Soft Contact Lens Wear

2012 ◽  
Vol 2012 ◽  
pp. 1-2
Author(s):  
Natasha Spiteri ◽  
Anshoo Choudhary ◽  
Stephen Kaye
Keyword(s):  
New York ◽  
Contact Lenses ◽  
Retrospective Case ◽  
Soft Contact ◽  
Contact Lens Wear ◽  
Soft Contact Lenses ◽  
Soft Contact Lens ◽  
Pathological Conditions ◽  
Normal Ageing ◽  
Lens Wear

Purpose. To report a case of pigmented corneal iron lines following use of tinted soft contact lenses (CL).Methods. A retrospective case report.Results. A 16-year-old girl was referred with suspected CL-related keratopathy OU, having recently switched to tinted soft monthly disposable CLs (8.4/14.0 −3.00 OD, −3.25 OS Aquamarine SofLens Natural Colours, Bausch and Lomb, New York, USA). Both corneas exhibited symmetric superficial corneal pigmented iron lines, which gradually disappeared following discontinuation of CL wear.Conclusions. Pigmented corneal rings have been reported in normal ageing corneas, in certain pathological conditions, and in association with altered corneal topography following LASIK and orthokeratology. We suspect a poorly fitting CL resulted in localised tear pooling between the CL and cornea, and subsequent iron pigment deposition, similar to that seen with orthokeratology. Cosmetic CLs bought via the Internet can be used in an unsupervised manner, with possible impacts on visual function and potential complications.

scholarly journals Contact Lens Visual Rehabilitation in Keratoconus and Corneal Keratoplasty

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Yelda Ozkurt ◽  
Mehmet Atakan ◽  
Tugba Gencaga ◽  
Sezen Akkaya
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Soft Contact ◽  
Visual Rehabilitation ◽  
Adequate Treatment ◽  
Contact Lens Wear ◽  
Soft Contact Lenses ◽  
Thinning Process ◽  
Lens Wear ◽  
Spectacle Correction

Keratoconus is the most common corneal distrophy. It’s a noninflammatory progressive thinning process that leads to conical ectasia of the cornea, causing high myopia and astigmatism. Many treatment choices include spectacle correction and contact lens wear, collagen cross linking, intracorneal ring segments implantation and finally keratoplasty. Contact lenses are commonly used to reduce astigmatism and increase vision. There are various types of lenses are available. We reviewed soft contact lenses, rigid gas permeable contact lenses, piggyback contact lenses, hybrid contact lenses and scleral-semiscleral contact lenses in keratoconus management. The surgical option is keratoplasty, but even after sutur removal, high astigmatism may stil exists. Therefore, contact lens is an adequate treatment option to correct astigmatism after keratoplasty.

Corneal Epithelial Thickness Map in Long-Term Soft Contact Lenses Wearers

2014 ◽  
Vol 91 (12) ◽  
pp. 1455-1461 ◽  
Author(s):  
Jiaxu Hong ◽  
Tingting Qian ◽  
Yujing Yang ◽  
Chunhui Jiang ◽  
Zuguo Liu ◽  
...  
Keyword(s):  
Contact Lenses ◽  
Soft Contact ◽  
Corneal Epithelial ◽  
Soft Contact Lenses ◽  
Epithelial Thickness ◽  
Corneal Epithelial Thickness

scholarly journals Bacterial Colonization of Disposable Soft Contact Lenses Is Greater during Corneal Infiltrative Events than during Asymptomatic Extended Lens Wear

2000 ◽  
Vol 38 (12) ◽  
pp. 4420-4424 ◽  
Author(s):  
Padmaja R. Sankaridurg ◽  
Savitri Sharma ◽  
Mark Willcox ◽  
Thomas J. Naduvilath ◽  
Deborah F. Sweeney ◽  
...  
Keyword(s):  
Risk Factor ◽  
Contact Lenses ◽  
Microbial Colonization ◽  
Gram Negative Bacteria ◽  
Soft Contact ◽  
Gram Positive ◽  
Gram Negative ◽  
Soft Contact Lenses ◽  
Gram Positive Bacteria ◽  
Lens Wear

Microorganisms, especially gram-negative bacteria, are considered to play a role in the etiology of certain corneal infiltrative events (CIEs) observed during soft contact lens wear. This study explored the possibility of microbial colonization of soft contact lenses as a risk factor leading to CIEs. In a clinical trial conducted from March 1993 to January 1996, 330 subjects wore disposable soft contact lenses on a 6-night extended-wear and disposal schedule. During this period, 4,321 lenses (118 during CIEs; 4,203 during asymptomatic lens wear) were recovered aseptically and analyzed for microbial colonization. A greater percentage of lenses were free from microbial colonization during asymptomatic wear than during CIEs (42 versus 23%;P < 0.0001). The incidence of gram-positive bacteria, gram-negative bacteria and fungi was greater during CIEs than during asymptomatic lens wear (P < 0.05). During asymptomatic lens wear, gram-positive bacteria were isolated most frequently and were usually normal external ocular microbiota. Of the gram-positive bacteria, the incidence of Streptococcus pneumoniae was greater during CIE than during asymptomatic wear (7.6 versus 0.6%; P < 0.0001). While gram-negative bacteria were seen in few cases during asymptomatic wear, their incidence during CIE in comparison to asymptomatic wear was substantial and significant (23.7 versus 3.8%; P < 0.0001). Also, the level of colonization was high. Of CIEs, events of microbial keratitis, contact lens acute red eye, and asymptomatic infiltrative keratitis were associated with lens colonization with gram-negative bacteria or S. pneumoniae. Colonization of soft contact lenses with pathogenic bacteria, especially gram-negative bacteria andS. pneumoniae, appears to be a significant risk factor leading to CIE.

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.

Evaluation of In Vitro Wettability of Soft Contact Lenses Using Tear Supplements

2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Hiroko Iwashita ◽  
Takashi Itokawa ◽  
Takashi Suzuki ◽  
Yukinobu Okajima ◽  
Koji Kakisu ◽  
...  
Keyword(s):  
Contact Lenses ◽  
Soft Contact ◽  
Soft Contact Lenses

In vitro wear and lubricity of soft contact lenses: shaken .. not stirred

2013 ◽  
Vol 36 ◽  
pp. e28
Author(s):  
W. Gregory Sawyer ◽  
Alison Dunn ◽  
Juan Uruena ◽  
William Vann ◽  
Thomas Angelini
Keyword(s):  
Contact Lenses ◽  
Soft Contact ◽  
Soft Contact Lenses
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