Background: The complex interaction between contact lens wear and therapeutic drug use can account for physical and physiological changes in contact lens tolerance as well as changes in lens appearance.
Methods/results: Selected therapeutic drug issues are reviewed and recommendations are provided to assist clinicians in choosing management strategies for lens and therapeutic agent selection.
Conclusions: The efficacy of drug absorption, whether from topical application or systemic secretion into the tear film, depends on the nature and water content of the polymer, lens thickness, drug and tear volume, and on adnexal and environmental factors. The "reservoir effect" of drug absorption in hydrogel lenses has led to its application as a method of enhanced drug delivery to the cornea and anterior segment. This same property, however, can also lead to excessive contact time between drug and cornea, leading to exacerbation of topical drug side effects and toxicity reactions with some therapeutic agents. Systemic medications used concurrently with contact lenses may have adverse effects on the blink mechanism and associated contact lens metabolism as well as on aqueous tear production, with resulting dry eye symptomatology.