title: Persistent Hypotony Associated with Immunosuppressive Therapy in Glaucoma Drainage Implant Surgery.
abstract: OBJECTIVE
  To describe the histopathology of non-valved implant capsules in three cases of persistent postoperative hypotony after the restrictive tube ligature was released in patients receiving immunosuppressive therapy.
  
  
  METHODS
  The macroscopic appearance of the capsules 3 and 4 months postoperatively was immature and loose. Microscopic examination disclosed extremely irregular thin tissue, with thicknesses ranging from 0.02 to 0.6 mm, depending on the capsular location studied. Withdrawal of immunosuppressive therapy did not facilitate rebuilding of new capsules. Replacement with a valved implant device was necessary in two cases; the third case recovered with tapering of prednisone.
  
  
  CONCLUSIONS
  The use of chronic systemic immunosuppressive therapy might interfere with capsular formation around the plates of drainage devices inducing persistent hypotony. In these cases, the use of valved implants might be safer.
authors: ICO - Instituto Condal de Oftalmología, Barcelona, Spain.
authors: Susana
authors: S
authors: Duch
authors: ICO - Instituto Condal de Oftalmología, Barcelona, Spain.
authors: Elena
authors: E
authors: Milla
authors: ICO - Instituto Condal de Oftalmología, Barcelona, Spain.
authors: Oana
authors: O
authors: Stirbu
authors: ICO - Instituto Condal de Oftalmología, Barcelona, Spain.
authors: David
authors: D
authors: Andreu
keywords: Ahmed valve; Corticosteroids; Cyclosporin; Glaucoma drainage devices; Hypotony; Immunosuppressant; Molteno implant; Mycophenolate mofetil; Tubes