An evaluation of silicone-hydrogel lenses worn on a daily wear basis

To examine the clinical performance of two brands of silicone-hydrogel lenses when worn on a daily wear basis.

Fifty-six subjects with no ocular disease were enrolled at multiple sites in Australasia. Contact lenses made from galyfilcon A or lotrafilcon A were randomly assigned to each eye of the subject and the lenses were worn on a daily wear basis for a period of two weeks. Subjects did not know the identity of the lenses they wore. Clinical data and patient responses to a questionnaire were gathered at an initial visit and after two weeks of wear.

For both lenses, the degree of limbal hyperaemia and bulbar conjunctival hyperaemia decreased significantly over the two-week wearing period. The eyes wearing galyfilcon A lenses showed an increase in conjunctival staining compared to the baseline measures. On average, galyfilcon A lenses decentred more and moved less than the lotrafilcon A lenses. The lotrafilcon A lenses showed a greater loss of wettability, as judged by practitioner grading, than the galyfilcon A lenses over the two-week period. The subjective responses showed strong preference for the galyfilcon A lens across 26 of 27 questions relating to comfort, vision, handling, preference and other subjective outcomes.

The results show that different silicone-hydrogel lenses have different performance characteristics on the eye, when worn on a daily wear basis. Striving for high oxygen transmissibility at the expense of other properties may lead to a range of undesirable performance characteristics.