To compare the clinical performance of silicone hydrogel lenses worn for 6- or 30-nights, with monthly replacement, for 3 years.
In this 3-year prospective clinical trial, 161 subjects were enrolled and 154 commenced extended wear. Clinical performance was assessed by comparing discontinuations and lens surface characteristics (front surface deposits, lens wettability, number of mucin balls), lens fitting performance (primary gaze movement, lens tightness), and physiologic parameters (limbal and bulbar redness, corneal and conjunctival staining, microcysts) and subjective parameters (ratings of comfort and vision) between groups.
Eighty-eight subjects remained in the study after 36 months. There were no differences in the probability of subjects surviving in either group, and the major cause of lens-related discontinuation in both groups was contact lens-induced papillary conjunctivitis. There were no clinically important differences in performance between wear schedules.
The long-term clinical performance of silicone hydrogels worn for 6- or 30-nights continuously was similar. Clinical markers of hypoxia were low in both groups, and the 6-night wear schedule was not superior to the 30-night wear schedule with regard to preventing lens spoilage, improving corneal physiology, or subjective symptoms of comfort and vision.