title: New corticosteroid-eluting porous polyethylene implant for the management of lower eyelid retraction: a pilot study.
abstract: OBJECTIVE
  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.
authors.affiliation: The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Garibaldi
authors.forename: Michael R
authors.initials: MR
authors.lastname: Robinson
authors.forename: Susan S
authors.initials: SS
authors.lastname: Lee
authors.forename: Dong Jun J
authors.initials: DJ
authors.lastname: Park
authors.forename: Howard F
authors.initials: HF
authors.lastname: Fine
authors.forename: Luke
authors.initials: L
authors.lastname: Deitz
authors.forename: Sam
authors.initials: S
authors.lastname: D'Anna
authors.forename: Peng
authors.initials: P
authors.lastname: Yuan
authors.forename: Nicholas
authors.initials: N
authors.lastname: Ranson
authors.forename: Michael P
authors.initials: MP
authors.lastname: Grant
authors.forename: Nicholas T
authors.initials: NT
authors.lastname: Iliff
authors.forename: Shannath L
authors.initials: SL
authors.lastname: Merbs
mesh_terms: D000818:Animals; D020099:Coated Materials, Biocompatible; D004195:Disease Models, Animal; D005141:Eyelid Diseases / Q000473:pathology / Q000601:surgery*; D005143:Eyelids / Q000473:pathology / Q000601:surgery*; D005938:Glucocorticoids / Q000494:pharmacology*; D010865:Pilot Projects; D011095:Polyethylenes; D016062:Porosity; D019736:Prostheses and Implants; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000295:instrumentation*; D011817:Rabbits; D016896:Treatment Outcome; D014222:Triamcinolone Acetonide / Q000494:pharmacology
chemical_list: D020099:Coated Materials, Biocompatible; D005938:Glucocorticoids; D011095:Polyethylenes; D014222:Triamcinolone Acetonide