scholarly journals Changes in the geometry of modern daily disposable soft contact lenses during wear

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Patryk Mlyniuk ◽  
Joanna Stachura ◽  
Alfonso Jiménez-Villar ◽  
Ireneusz Grulkowski ◽  
Bartlomiej J. Kaluzny
Keyword(s):  
Optical Coherence Tomography ◽  
Contact Lenses ◽  
Correlation Coefficients ◽  
Geometrical Parameters ◽  
Soft Contact ◽  
Corneal Surface ◽  
Swept Source ◽  
Silicone Hydrogel ◽  
Soft Contact Lenses ◽  
The Mean

AbstractThe geometry of contact lenses can be altered by wear but determining the changes that occur in soft contact lenses (SCLs) is challenging. This study aimed to investigate the shape alterations of daily disposable SCLs after wear using swept-source optical coherence tomography (SS-OCT). Forty-five eyes with myopia of − 3.00 diopters (D) were enrolled. The participants wore three types of SCLs: hydrogel lens (nesofilcon A) and silicone hydrogel lenses (delefilcon A and stenfilcon A). The SCLs were scanned 3–6 min after lens removal. We found a significant decrease in the SCL anterior curvature: 0.24 ± 0.17 mm for nesofilcon A, 0.44 ± 0.21 mm for delefilcon A, and 0.53 ± 0.29 mm for stenfilcon A. The changes in the anterior curvature of SCLs correlated moderately with the mean corneal keratometry; Pearson’s correlation coefficients for nesofilcon A and delefilcon A were 0.57 and 0.52, respectively (P < 0.001). A statistically significant change in the total diameter was observed in SCL made of stenfilcon A (0.39 mm, P < 0.001). To conclude, the central radii of curvature decreased after a wearing period for all three types of daily disposable SCLs to imitate the anterior corneal surface, however, the changes in other geometrical parameters measured with SS-OCT were lens-specific.

scholarly journals Effects of Blink Rate on Tear Film Optical Quality Dynamics with Different Soft Contact Lenses

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
María García-Montero ◽  
Laura Rico-del-Viejo ◽  
Irene Martínez-Alberquilla ◽  
Jose Luis Hernández-Verdejo ◽  
Amalia Lorente-Velázquez ◽  
...  
Keyword(s):  
Contact Lenses ◽  
Tear Film ◽  
Optical Quality ◽  
Blink Rate ◽  
Soft Contact ◽  
Double Blind ◽  
Silicone Hydrogel ◽  
Soft Contact Lenses ◽  
The Mean ◽  
Over Time

Objective. The aim of this study was to investigate tear film optical quality dynamics for four types of silicone hydrogel contact lenses (SHCLs) for daily wear over a 15-day period and for different blink rate (BR) patterns. Methods. A prospective randomized, double-blind, cross-over pilot study including four SHCLs (A: lotrafilcon B (Air Optix plus HydraGlyde, Alcon Laboratories); B: samfilcon A (Ultra, Bausch & Lomb); C: comfilcon A (Biofinity, CooperVision); and D: filcom V3 (Blu:gen, Mark’Ennovy)). Serial measurements of Objective Scatter Index (OSI) using the HD Analyzer (Visiometrics S.L., Terrassa, Spain) were taken at different blinking patterns: blinking every 2.5 seconds (high BRs) and every 9 seconds (low BRs). They were performed during the first visit before CL insertion (baseline), after 20 minutes of CL wear (Day 1), and during the last visit after 8 hours of CL wear on day 15 of use (Day 15). Results. Normal young healthy subjects were recruited and fitted with the four lenses. For low BRs, the mean OSI value increased over time for all CLs and the slope of the curve also increased for all CLs, except for CL D. However, for high BRs, the mean OSI value increased only for CLs B and C and the slope of the curve did not change over time for any of them. Conclusions. These results suggest that the tear film optical quality dynamics after wearing SCHLs for 15 days seems to undergo a slight deterioration only for lowest BR.

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 Biomimetic Functional Surfaces towards Bactericidal Soft Contact Lenses

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 835
Author(s):  
Tianyu Mao ◽  
Fengzhou Fang
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Contact Lenses ◽  
Influence Factors ◽  
Interaction Mechanism ◽  
Holistic Approach ◽  
Geometrical Parameters ◽  
Physical Interaction ◽  
Soft Contact ◽  
Soft Contact Lenses

The surface with high-aspect-ratio nanostructure is observed to possess the bactericidal properties, where the physical interaction between high-aspect-ratio nanostructure could exert sufficient pressure on the cell membrane eventually lead to cell lysis. Recent studies in the interaction mechanism and reverse engineering have transferred the bactericidal capability to artificial surface, but the biomimetic surfaces mimicking the topographical patterns on natural resources possess different geometrical parameters and surface properties. The review attempts to highlight the recent progress in bactericidal nanostructured surfaces to analyze the prominent influence factors and cell rupture mechanism. A holistic approach was utilized, integrating interaction mechanisms, material characterization, and fabrication techniques to establish inclusive insights into the topographical effect and mechano-bactericidal applications. The experimental work presented in the hydrogel material field provides support for the feasibility of potentially broadening applications in 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.

Effects of Refractive Power on Macular Thickness Measurement Using Spectral-Domain Optical Coherence Tomography

2015 ◽  
Vol 234 (3) ◽  
pp. 172-176 ◽  
Author(s):  
Sung Bok Lee ◽  
Il Hwan Shin ◽  
Kyung Sup Shin ◽  
Young Joon Jo ◽  
Jung Yeul Kim
Keyword(s):  
Optical Coherence Tomography ◽  
Contact Lenses ◽  
Macular Thickness ◽  
Spectral Domain ◽  
Central Macular Thickness ◽  
Optical Coherence ◽  
Soft Contact ◽  
Soft Contact Lenses ◽  
Refractive Power ◽  
Sd Oct

Purpose: To investigate the effects of refractive power on macular thickness measurements by spectral-domain optical coherence tomography (SD-OCT). Subjects and Methods: For this prospective cohort study, a total of 50 eyes from 50 normal subjects with no systemic or ocular disease and no history of ocular surgery were studied from February 2014 to May 2014. We used soft contact lenses with a wide range of diopters to change the refractive power. The macular thickness of uncorrected eyes without contact lenses was measured by SD-OCT, and we compared the findings with the results of subsequent investigations in which macular thickness was measured in the presence of soft contact lenses of different diopters (-8, -4, 0, +4, and +8). We divided the patients into three groups according to the axial length (AL) and analyzed the effect of induced refraction change. The main outcome measure was macular thickness measured by OCT. Results: The average age of the subjects was 28.0 ± 3.4 years (mean ± SD), and included 17 eyes with normal AL, 18 eyes with mid-range AL, and 15 eyes with long AL. The central macular thickness was 254.5 ± 17.5 µm for eyes without contact lenses, which was not significantly different from the measurements in the presence of plano contact lenses (254.2 ± 18.1 µm). Even with soft contact lenses of four different diopters (-8, -4, +4, and +8), central macular thickness (254.4 ± 16.2, 253.7 ± 17.3, 257.3 ± 17.9, and 256.9 ± 17.9 µm, respectively) was not significantly different from that of naked eyes in each group. Conclusion: These results suggest that central macular thickness measured by SD-OCT is unaffected by refractive power.

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.

Sign in / Sign up

Export Citation Format

Share Document