title: A histopathologic study of orbital implant vascularization.
abstract: OBJECTIVE
  To histopathologically assess the extent and pattern of vascularization of explanted porous polyethylene (PP) and hyrdoxyapatite (HA) orbital implants. To compare the vascularization in PP implants harvested after enucleation versus after evisceration.
  
  
  METHODS
  This is a comparative case series of six orbital implants explanted between 11 months and 5 years and 4 months post implantation. The implants were subjected to histopathological examination with various stains, after complete decalcification.
  
  
  RESULTS
  There were 2 post evisceration, 3 post enucleation and 1 secondary implant. The size of the implants varied from 18 to 23 mm diameter. The reason for explantation was exposure in all the 6 cases with additional infection in 2 cases. Histopathology revealed complete vascularization up to the core of the implant in all the cases. There was evidence of chronic inflammation within all the explanted specimens. Acute inflammation was present at the site of exposure in four of the implants. Three of these implants had additional evidence of necrosis. Two cases with clinically evident infection had Gram positive cocci within the implant. Foreign-body type giant-cells, melanophages and haemosiderin laden macrophages were also observed. Eviscerated specimens showed scleral remodelling and thickening.
  
  
  CONCLUSIONS
  All the implants were vascularized up to the core. There was histologic evidence of chronic inflammation in all the explanted implants possibly indicating the foreign nature of the implant material. The sclera did not impede vascularization of the implants in eviscerated specimens. We found no difference in the degree of vascularization of the implant in enucleated versus eviscerated implants.
authors.affiliation: Wolverhampton and Midland Counties Eye Infirmary, New Cross Hospital, Wolverhampton.
authors.forename: Katya
authors.initials: K
authors.lastname: Tambe
authors.forename: Sreekumari
authors.initials: S
authors.lastname: Pushpoth
authors.forename: Hardeep S
authors.initials: HS
authors.lastname: Mudhar
authors.forename: Soupramanien
authors.initials: S
authors.lastname: Sandramouli
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D001672:Biocompatible Materials; D017886:Durapatite; D015353:Eye Enucleation; D017234:Eye Evisceration; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018919:Neovascularization, Physiologic; D009915:Orbit / Q000098:blood supply* / Q000601:surgery; D020273:Orbital Implants; D020959:Polyethylene; D013194:Staining and Labeling
chemical_list: D001672:Biocompatible Materials; D020959:Polyethylene; D017886:Durapatite