Use of collagen shields for ocular-surface drug delivery

Collagen shields are contact lens-shaped, dissolvable protein matrixes placed on the cornea, primarily indicated for the promotion of epithelial wound healing. The shield can also serve to deliver ocular medications if soaked in a water-soluble antibiotic and/or steroid solution prior to their placement. Collagen shields have distinct advantages over other precorneal drug reservoirs, such as intensive topical therapy, which inconveniences both the patients and caregivers, and subconjunctival injections, which risks hemorrhaging and perforation. It has also been suggested that collagen shields can be used to augment ocular tissue concentrations of various medications over topical administration alone. Despite these potential advantages, the use of collagen shields in drug delivery has not become common practice. In this article, we summarize the evidence for and against the use of collagen shields in delivering and sustaining high levels of ocular therapeutics, with a special focus on the prevention of postoperative endophthalmitis.