title: Trabeculectomy Versus EX-PRESS Shunt Versus Ahmed Valve Implant: Short-term Effects on Corneal Endothelial Cells.
abstract: OBJECTIVE
  To evaluate short-term changes in corneal endothelial cells after trabeculectomy, EX-PRESS device implantation, and Ahmed valve implantation for the treatment of primary open-angle glaucoma.
  
  
  METHODS
  Prospective, interventional, comparative case series with contralateral eye control study.
  
  
  METHODS
  We prospectively evaluated the changes in number, density, and shape of the corneal endothelium cells in 128 eyes of 64 patients divided into 3 groups depending on the treatment received. Corneal specular microscopy was performed with a noncontact specular microscope preoperatively and at 1 and 3 months after surgery. The changes at each time point were compared with those of the control group, which consisted of 32 contralateral glaucomatous eyes receiving antiglaucoma medications without any previous glaucoma surgery.
  
  
  RESULTS
  In the subjects who underwent trabeculectomy, corneal endothelial cell density (ECD) significantly decreased by 3.5% (P = .012, paired t test) at 1 month and 4.2% (P = .007) at 3 months after surgery, compared to the baseline values. In the Ahmed valve group ECD did not change at 1 month after surgery and had a significant 3.5% decrease at 3 months (P = .04). In the patients who underwent EX-PRESS implantation and in the control group ECD did not change either at 1 month or at 3 months after surgery (P > .05).
  
  
  CONCLUSIONS
  EX-PRESS shunt, compared to trabeculectomy and Ahmed valve, seems to be a safer procedure regarding the risk of endothelial cell loss. For this reason, it may be the treatment of choice in patients with significant low corneal ECD before surgery or other risk factors for corneal damage.
authors: Ophthalmology Unit, Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy.
authors: Giamberto
authors: G
authors: Casini
authors: Ophthalmology Unit, Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy. Electronic address: ldcpasquale@gmail.com.
authors: Pasquale
authors: P
authors: Loiudice
authors: Ophthalmology Unit, Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy.
authors: Marco
authors: M
authors: Pellegrini
authors: Ophthalmology Unit, Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy.
authors: Angela Tindara
authors: AT
authors: Sframeli
authors: Ophthalmology Unit, Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy.
authors: Paolo
authors: P
authors: Martinelli
authors: Ophthalmology Unit, Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy.
authors: Andrea
authors: A
authors: Passani
authors: Ophthalmology Unit, Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy.
authors: Marco
authors: M
authors: Nardi
mesh_terms: D000368:Aged; D002452:Cell Count; D004728:Endothelium, Corneal / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D020327:Glaucoma Drainage Implants; D005902:Glaucoma, Open-Angle / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012590:Sclera / Q000601:surgery*; D014065:Tonometry, Ocular; D014130:Trabeculectomy / Q000379:methods*