Influence of wearing schedule on extended-wear complications.

The effect of wearing schedule on extended-wear (EW) success was evaluated over a nine-month period by assigning 36 subjects to 5 different wearing schedules (removal every 4, 7, 14, or 28 days, or daily wear [DW]). All but one EW patient required interruption of extended wear at least once; half of the DW patients completed the study without interruption. The most prevalent (100%) complication in the EW group was epithelial microcysts; 54% had to discontinue EW for 67 +/- 30 days while severe microcysts subsided. Evidence is given for a hypoxic etiology of microcysts. Other EW complications included: persistent punctate keratitis, infiltrative keratitis, infection, and idiopathic red eye. Neither the level of overnight corneal swelling nor the period between removals influenced the incidence or severity of complications. Data is given on the recovery of corneal parameters after EW is discontinued.