Adaptation to Paraperm extended wear lenses: a clinical study in Sweden.

Paraperm EW, a new, rigid gas-permeable material with a Dk of 56 X 10(-11) was manufactured into contact lenses in Sweden. One hundred-five patients were fitted including three patients with aphakia, seven with keratoconus and 17 with astigmatism of 2.5 D or more. In this initial study of adaptation, these lenses were worn on a daily basis with a 95% success rate. Over one-third of the patients were previously unsuccessful with PMMA, other rigid gas-permeable, or soft lenses. Complications such as corneal staining (7%) and lens coating (9%) were all reversible. The results during a three-month period showed a high success rate for daily wear and a favorable potential for extended wear. The major advantages of these lenses over other rigid gas-permeable lenses are a high Dk, initial comfort, quick adaptation and minimal complications.