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White light interferometry to characterize the hydrogel contact lens surface

Uncorrected proof ; Purpose: The aim of this study was to characterize, qualitatively and quantitatively, the surface morphology of four unworn conventional hydrogel contact lenses (Omafilcon, Hioxifilcon-based, Nefilcon A and Ocufilcon B) by White Light Optical Profiling (WLOP). WLOP is an ideal technique for sampling larger areas as well as for higher measurement speed compared with other topography techniqu...

The influence of lens material and lens wear on the removal and viability of st...

Purpose: The aim of this study was to evaluate the influence of lens material and lens wear on the removal capability of Staphylococcus epidermidis. Assessment of viability of remaining adhered bacteria was another goal of this work. Four silicone hydrogel materials (galyfilcon A, balafilcon A, lotrafilcon A, lotrafilcon B) and one conventional hydrogel material (etafilcon A) were assayed. Methods: Detachment s...

The effect of lens wear on refractive index of conventional hydrogel and silico...

Purpose: The purpose of this work was to evaluate the ability of four silicone-hydrogel contact lenses (galyfilcon A, balafilcon A, lotrafilcon A and lotrafilcon B) to retain their equilibrium water content before and after wear, through measurements of refractive index and compare with that of a conventional disposable hydrogel contact lens (etafilcon A). Methods: The refractive indices of 115 contact lenses w...

Changes in UVR-Visible transmittance induced by wear on silicone-hydrogel conta...

Comparative study of silicone-hydrogel contact lenses Surfaces before and after...

Purpose: The aim of this study was to analyze surface changes of three silicone-hydrogel contact lenses after daily wear. The lenses used in this study were balafilcon A, lotrafilcon B (both surface-treated), and galyfilcon A (non surface-treated). Methods: To understand how and where proteins, lipids, and other contaminants change contact lenses, surface roughness was assessed through Atomic Force Microscopy T...

Bacterial adhesion to worn silicone hydrogel contact lenses

Purpose. The aim of this study was to, firstly, investigate whether silicone-hydrogel contact lenses (CL) are more or less susceptible to bacterial adhesion than conventional ones and, secondly, assess the influence of lens wear in the extent of bacterial adhesion. Four silicone-hydrogel CL (galyfilcon A, balafilcon A, lotrafilcon A, and lotrafilcon B) and one conventional hydrogel (etafilcon A) CL were tested....

The influence of surface treatment on hydrophobicity, protein adsorption and mi...

Purpose: To evaluate the influence of surface treatment of silicone-hydrogel CL on lens hydrophobicity, protein adsorption and microbial colonisation by studying several silicone hydrogel contact lenses (CL) with and without surface treatment. The lenses used in this study were Balafilcon A, Lotrafilcon A, Lotrafilcon B and Galyfilcon A. A conventional hydrogel CL (Etafilcon A) was also tested. Methods: Hydroph...

The effect of octylglucoside and sodium cholate in Staphylococcus epidermidis a...

Purpose. In this study, the effect of the natural surfactants octylglucoside and sodium cholate in inhibiting Staphylococcus epidermidis and Pseudomonas aeruginosa adhesion to conventional and silicone-hydrogel contact lenses (CL) was assessed. Hydrophobicity was also evaluated to conditioned and nonconditioned CL. Methods. The inhibiting effect of the tested surfactants was determined through “in vitro” adhesi...

The effect of silicone-hydrogel and conventional hydrogel contact lenses wear o...

Purpose: The aim of this study was to evaluate the effect of one conventional hydrogel and four silicone-hydrogel contact lenses of 6-months daily wear on the quantity and stability of the tear film. The tests were performed with a group of patients with no previous contact lenses experience before and after wear on 96 eyes. Methods: The contact lenses tested were: 19 Galyfilcon A (Acuvue® Advance™), 15 Balafil...

Comparative study of silicone-hydrogel contact lenses surfaces before and after...