title: Partial thickness corneal tissue as a patch graft material for prevention of glaucoma drainage device exposure.
abstract: BACKGROUND
  To protect from erosion of the tube in glaucoma drainage device (GDD), the tube is covered by a biologic tissue which is roofed by the conjunctiva. Sclera, pericardium, dura mater and cornea are available as a patch graft. Drawbacks of some of these materials may include high cost and poor appearance. The purpose of this study is to report the long-term outcomes of partial thickness corneal grafts to cover the tube and prevent its exposure, in GDD surgeries.
  
  
  METHODS
  This was a retrospective review of all patients who underwent Ahmed glaucoma valve implantation and had a minimum follow-up of 12 months. The tube was covered by a 300-micron partial thickness corneal graft taken either from a previous Descemet stripping endothelial keratoplasty procedure or cut from a whole corneal graft button unsuitable for keratoplasty.
  
  
  RESULTS
  Forty-four patients (45 eyes, mean follow-up of 27.6 ± 11.4 months) were enrolled. The partial thickness corneal grafts maintained clarity throughout follow-up with satisfactory cosmetic results. Mild conjunctival retraction occurred in 4 eyes (8.9%) between 1 and 12 months after the surgery. Corneal graft melting occurred in 3 (6.7%) eyes. Tube exposure and additional surgery to re-patch or suture the conjunctiva over the tube was needed in 1 (2.2%) eye. None of the patients had graft infection or immunologic rejection.
  
  
  CONCLUSIONS
  Partial thickness corneal grafts have favorable long-term outcome as a patch for GDD tubes with low rates of tube exposure and other complications.
authors.affiliation: Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, 6 Weizmann Street, Tel Aviv, 64239, Israel. oriels1@yahoo.com.
authors.forename: Oriel
authors.initials: O
authors.lastname: Spierer
authors.affiliation: Wills Eye Hospital, Philadelphia, PA, USA. mwaisbourd@willseye.org.
authors.forename: Michael
authors.initials: M
authors.lastname: Waisbourd
authors.affiliation: Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, 6 Weizmann Street, Tel Aviv, 64239, Israel. golanizak@hotmail.com.
authors.forename: Yitzhak
authors.initials: Y
authors.lastname: Golan
authors.affiliation: Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, 6 Weizmann Street, Tel Aviv, 64239, Israel. hadasng@gmail.com.
authors.forename: Hadas
authors.initials: H
authors.lastname: Newman
authors.affiliation: Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, 6 Weizmann Street, Tel Aviv, 64239, Israel. rony.rachmiel@gmail.com.
authors.forename: Rony
authors.initials: R
authors.lastname: Rachmiel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003315:Cornea; D005260:Female; D005500:Follow-Up Studies; D058752:Free Tissue Flaps; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000517:prevention & control*; D011475:Prosthesis Failure; D019919:Prosthesis Implantation / Q000379:methods*; D060489:Prosthesis Retention / Q000379:methods*; D012189:Retrospective Studies