RESUMO
PURPOSE: Lower eyelid retraction after trauma presents a challenging management problem. We postulated that a porous polyethylene (pPE) eyelid spacer coated with a polyvinyl alcohol (PVA) and triamcinolone acetonide (TA) matrix could deliver corticosteroid locally over extended periods and modulate inflammation and scar formation. We designed a pPE corticosteroid-eluting implant and evaluated its characteristics in vitro and in vivo. METHODS: The release characteristics of pPE implants coated with a PVA/TA matrix of low, intermediate, and high doses of TA were studied in vitro. The implants were then placed in the posterior lamella of lower eyelids of Dutch Belted rabbits for 12 weeks. Clinical events were recorded and eyelids were examined for gross and histologic features, including capsular thickness and degree of vascularity, fibrovascular ingrowth, and inflammatory response. RESULTS: In vitro, implants coated with the intermediate and high doses of TA released the drug at a steady rate for at least 78 days. In rabbits, the PVA and PVA/TA coating prevented fibrovascular ingrowth, except where breaks in the PVA/TA coat were present. Implants with PVA/TA coating demonstrated less inflammation and capsule vascularity. An inverse correlation between TA dose and capsule thickness was noted. CONCLUSIONS: We describe a novel drug-release pPE eyelid implant. The corticosteroid-eluting implant demonstrated antiangiogenic and anti-inflammatory properties, which could prove beneficial in the treatment of lower eyelid retraction.
