Practitioner guidelines for continuous wear with high Dk silicone hydrogel contact lenses

From a patient’s perspective, the ultimate mode of vision correction is one that provides excellent vision in a safe, comfort- able and convenient, fuss-free form. Although laser surgery offers permanent vision correction, the refractive outcome cannot always be accurately predicted, especially for correction of extreme myopia. Highly oxygen permeable (Dk) soft contact lenses that can be worn for up to 30 nights of extended wear without re- placement (continuous wear) offer a comfortable and convenient form of lens wear that is free from hypoxia normally associated with extended wear. Our surveys indicate that up to 66 per cent of patients will consider refractive laser surgery as a permanent means of overcoming their vision correction and that only 32 per cent are still interested in laser surgery after experiencing continuous wear. Of the 74 patients surveyed, 88 per cent indicated that after an average of 12 months of experience with high Dk continuous wear, convenience is the major reason that they are satisfied with high Dk lenses. High Dk lenses are made from silicone hydrogel materials that are slightly stiffer and have a relatively lower water content than traditional low Dk hydrogel materials. Lenses made from lotrafilcon A and balafilcon A (Table 1) have been available in Australia and on the international market since 1999 and have shown tremendous growth in the short period since then. In a recent comparison of fitting trends in Australia, Woods and Morgan found that 14 per cent of new fits are made with high Dk silicone hydrogel lenses. This paper is designed as an aid to practitioners when dispensing high Dk silicone hydrogel lenses. It covers the areas of patient selection, fitting assessment, after-care and patient education.