Details

Autor(en) / Beteiligte

• Lira, M
• Santos, L
• Azeredo, J
• Yebra-Pimentel, E
• Real Oliveira, M.E.C.D

Titel

The effect of lens wear on refractive index of conventional hydrogel and silicone-hydrogel contact lenses: A comparative study

Ist Teil von

• Contact lens & anterior eye, 2008-04, Vol.31 (2), p.89-94

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2008

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Abstract 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 were measured using an automated refractometer (CLR 12-70, Index Instruments, Cambridge, U.K.) before and after a schedule of daily wear by 58 patients for 30 days in the case of silicone-hydrogel lenses and 15 days for the conventional contact lenses. Results In the silicone-hydrogel contact lenses the changes on the refractive indices were not statistically significant, however after being worn the refractive index of the conventional etalfilcon A hydrogel contact lens increased significantly ( p < 0.001). Conclusion The results presented here show that after being worn the silicone-hydrogel contact lens, show more capacity to retain or to reach their initial equilibrium water content than conventional hydrogel contact lenses. This suggests that the silicone-hydrogel contact lenses are less susceptible to spoilation over time maintaining its biocompatibility and contributing to the clinical success of lens performance.