title: Comparative study of encapsulated blebs following Ahmed glaucoma valve implantation and trabeculectomy with mitomycin-C.
abstract: OBJECTIVE
  To compare the histopathologic and morphologic findings of encapsulated blebs following Ahmed glaucoma valve implantation and primary standard trabeculectomy with mitomycin-C.
  
  
  METHODS
  We reviewed the records of patients with otherwise uncontrollable glaucoma who had undergone Ahmed glaucoma valve implantation or trabeculectomy with mitomycin-C. Five eyes that underwent Ahmed valve implantation and three eyes that underwent trabeculectomy needed surgical revision of the initial surgery due to encapsulated bleb development with total loss of function. The surgically removed encapsulated blebs were analyzed macroscopically and microscopically.
  
  
  RESULTS
  Removal of the encapsulated bleb was performed at a mean follow-up time of 26.6 ± 19.4 weeks in the Ahmed valve implantation group and 12.0 ± 11.4 weeks in the trabeculectomy group. The fibrotic wall of the encapsulated blebs had an overall thickness of 2.48 ± 0.42 mm in the Ahmed valve implantation group and 1.62 ± 0.37 mm in the trabeculectomy group. Macroscopically, the coconut flesh-like smooth surface was split into two layers, and the wall of the capsule was thicker in the Ahmed valve implantation group than in the trabeculectomy group. Histopathologically, the fibrotic capsule was composed of an inner fibrodegenerative layer and an outer fibrovascular layer, and there were no histopathological differences between the two groups.
  
  
  CONCLUSIONS
  The fibrotic capsule wall was thicker in the Ahmed valve group, but there were no differences in histological findings between the two groups.
authors.affiliation: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kunho
authors.initials: K
authors.lastname: Bae
authors.forename: Wool
authors.initials: W
authors.lastname: Suh
authors.forename: Changwon
authors.initials: C
authors.lastname: Kee
mesh_terms: D000328:Adult; D001768:Blister / Q000601:surgery*; D005260:Female; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D016685:Mitomycin / Q000627:therapeutic use*; D019384:Nucleic Acid Synthesis Inhibitors / Q000627:therapeutic use*; D012086:Reoperation; D014130:Trabeculectomy; D016896:Treatment Outcome
chemical_list: D019384:Nucleic Acid Synthesis Inhibitors; D016685:Mitomycin