Purpose: The current study prospectively evaluates the response to daily and extended wear of disposable lenses with each patient acting as his/her own control. This paradigm allowed for elimination of individual variation as a confounding factor, as well as determining whether an intrinsic factor, other than lens wear, predisposed patients to complications.
Methods: One hundred thirty-four patients were randomly assigned to contralateral daily wear (DW) or extended wear (EW) with Acuvue lenses for 1 year. All lenses were disposed of on a weekly basis. Bilateral bacteriology of lids, conjunctivae, lenses, and fingers was carried out on those patients presenting with complications.
Results: The results after 1 year indicate a higher incidence of complications in the EW eye (peripheral infiltrative keratopathy, 12%; corneal striae, 3%). No significant clinical complications occurred in the DW eye. Microbiological cultures did not reveal any significant difference between those eyes with keratopathy and those of controls. The most common pathogen was Staphyloccocus epidermidis. No gram-negative organisms grew from any of the culture sites.
Conclusions: The results of this study indicate that extended wearing schedules, and not the lens entity, predispose the patient to a higher risk of keratopathy with disposable contact lenses. No microbiological association with the adverse events could be determined, and no intrinsic patient factor could be demonstrated that would predict the likelihood of complications.