COLL 42 |
| Curtis McKenney and John McNally. Global Clinical Affairs, CIBA Vision Corporation, Duluth, GA 30097 |
| In the past 1.5 years two companies have received Food and Drug Administration (FDA) approval for silicone hydrogel contact lenses which can be worn continuously for up to 30 days and nights of extended wear. Historically, in the mid 1980’s, the FDA reduced similar approvals for hydrogel contact lenses to 6 nights of extended wear following epidemiological studies showing an increased rate of microbial keratitis. The hypothesis was that the low transmission of oxygen through these materials caused an unacceptable risk for the development of serious complications. The new silicone materials are block copolymers consisting of hydrophobic and hydrophilic segments which allow the transport of 4-6 times the amount of oxygen as compared to conventional hydrogel materials. Clinical performance has been improved with these silicone based materials, however, some complications still exist. Chemical and physical properties and clinical performance of current silicone hydrogel lenses will be discussed. |
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ACS Award in Colloid and Surface Chemistry Symposium Honoring Clay Radke
Division of Colloid and Surface Chemistry |