Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/18475

TitleChanges in UV-visible transmittance of silicone-hydrogel contact lenses induced by wear
Author(s)Lira, Madalena
Castanheira, Elisabete M. S.
Santos, Lívia
Azeredo, Joana
Yebra-Pimentel Vilar, Eva
Oliveira, M. Elisabete
KeywordsTransmittance
Ultraviolet radiation
Visible spectra
Silicone-hydrogel contact lenses
Issue dateApr-2009
PublisherAmerican Academy of Optometry (AAOPT)
JournalOptometry and Vision Science
Abstract(s)Purpose: To evaluate the influence of wear of silicone-hydrogel contact lenses on lens ultraviolet and visible spectrum transmittance by studying several contact lenses before and after wear. Methods: To investigate the ability of contact lenses to maintain their transmittance characteristics, we measured 104 different contact lenses in the ultraviolet (UV) and visible range from 200 to 700 nm, with a Shimadzu UV3101-PC UV-vis-NIR spectrophotometer equipped with an integrating sphere. The lenses used in this study were Acuvue Advance (Johnson & Johnson Vision Care, Inc.), Air Optix Night & Day (CIBA Vision), Air Optix (CIBA Vision), and PureVision (Bausch & Lomb). A conventional hydrogel contact lens was also tested, Acuvue (Johnson & Johnson Vision Care Inc.). Results: Our study indicates that lenses that do not have UV absorbers incorporated into the polymer transmitted most of the UV radiation (UVR) before and after wear. The results of the statistical analysis show that for the UVC portion of the spectrum significant difference exists within the measurements obtained before and after wear for all the lenses, with the exception of PureVision. Acuvue Advance is the only material in which significant transmittance differences were observed in the visible spectral range. Conclusions: Transmittance is modified after contact lenses wear, probably due to the formation of biofilms on the contact lens surface, being more noticeable in the UVR region of the spectrum (200–400 nm). Silicone-hydrogel and conventional hydrogel contact lens materials that provide UVR protection (UV-blocker) maintain this property even after being worn. The changes observed in the visible spectrum seem not to have any implications in visual performance of silicone-hydrogel contact lenses.
TypeArticle
URIhttp://hdl.handle.net/1822/18475
DOI10.1097/OPX.0b013e318198d047
ISSN1538-9235
Peer-Reviewedyes
AccessRestricted access (UMinho)
Appears in Collections:CDF - FAMO - Artigos/Papers (with refereeing)

Files in This Item:
File Description SizeFormat 
OVS2009_Transmittance.pdf
  Restricted access
Documento principal402,53 kBAdobe PDFView/Open

Partilhe no FacebookPartilhe no TwitterPartilhe no DeliciousPartilhe no LinkedInPartilhe no DiggAdicionar ao Google BookmarksPartilhe no MySpacePartilhe no Orkut
Exporte no formato BibTex mendeley Exporte no formato Endnote Adicione ao seu ORCID