title: Foreign body reaction in glaucoma drainage implant surgery.
abstract: OBJECTIVE
  To investigate the histopathology of the foreign body reaction (FBR) and the effect of aqueous humor on it in glaucoma drainage implant surgery.
  
  
  METHODS
  A glaucoma drainage device was implanted into 20 New Zealand white rabbits. We monitored the histopathology of blebs at microscopic levels from 3 days to 8 weeks postoperatively. Hematoxylin and eosin staining, Masson's trichrome staining, anti-actin and α-smooth muscle immunofluorescence staining, and antiproliferating cell nuclear antigen immunohistochemistry were performed. To observe effects of aqueous humor on FBR, we designed two implant models. One group received a plate with a tube placed in the anterior chamber (experimental group), whereas the other received the plate cut from the tube (control group).
  
  
  RESULTS
  Foreign body giant cells were found along the inner border of blebs, and the innermost layer of blebs demonstrated a densely packed collagenous stratum in both groups. The number of foreign body giant cells was suppressed in the experimental group compared with the control group (P < 0.001). Fibroblast division was more active in the experimental group than that in the control group. Masson's trichrome staining demonstrated that the innermost avascular collagenous layer was much thicker in the experimental group than that in the control group (P = 0.021). The extent of α-SMA staining was greater in the experimental group than that in the control group.
  
  
  CONCLUSIONS
  In the aqueous humor environment, wound healing around a glaucoma drainage implant revealed a unique FBR with the relatively small number of foreign body giant cells and reinforced fibrotic encapsulation.
authors.affiliation: Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Kyoung In
authors.initials: KI
authors.lastname: Jung
authors.forename: Seong-Beom
authors.initials: SB
authors.lastname: Lee
authors.forename: Jie Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Chan Kee
authors.initials: CK
authors.lastname: Park
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D001082:Aqueous Humor / Q000502:physiology; D015415:Biomarkers / Q000378:metabolism; D054338:Cell Transdifferentiation; D003094:Collagen / Q000378:metabolism; D005129:Eye Foreign Bodies / Q000473:pathology*; D005347:Fibroblasts / Q000473:pathology; D005355:Fibrosis; D019084:Fluorescent Antibody Technique, Indirect; D005549:Foreign-Body Reaction / Q000473:pathology*; D015726:Giant Cells / Q000473:pathology*; D020327:Glaucoma Drainage Implants; D007429:Intraocular Pressure; D023421:Models, Animal; D058628:Myofibroblasts / Q000473:pathology; D011817:Rabbits; D014945:Wound Healing / Q000502:physiology
chemical_list: D000199:Actins; D015415:Biomarkers; D003094:Collagen
keywords: aqueous humor; foreign body reaction; glaucoma drainage implant surgery; myofibroblast; wound healing