title: Heavy silicone oil versus standard silicone oil as vitreous tamponade in inferior PVR (HSO Study): design issues and implications.
abstract: OBJECTIVE
  Proliferative vitreoretinopathy (PVR) is the most important reason for blindness following retinal detachment. Presently, vitreous tamponades such as gas or silicone oil cannot contact the lower part of the retina. A heavier-than-water tamponade displaces the inflammatory and PVR-stimulating environment from the inferior area of the retina. The Heavy Silicone Oil versus Standard Silicone Oil Study (HSO Study) is designed to answer the question of whether a heavier-than-water tamponade improves the prognosis of eyes with PVR of the lower retina.
  
  
  METHODS
  The HSO Study is a multicentre, randomized, prospective controlled clinical trial comparing two endotamponades within a two-arm parallel group design. Patients with inferiorly and posteriorly located PVR are randomized to either heavy silicone oil or standard silicone oil as a tamponading agent. Three hundred and fifty consecutive patients are recruited per group. After intraoperative re-attachment, patients are randomized to either standard silicone oil (1000 cSt or 5000 cSt) or Densiron((R)) as a tamponading agent. The main endpoint criteria are complete retinal attachment at 12 months and change of visual acuity (VA) 12 months postoperatively compared with the preoperative VA. Secondary endpoints include complete retinal attachment before endotamponade removal, quality of life analysis and the number of retina affecting re-operation within 1 year of follow-up.
  
  
  RESULTS
  The design and early recruitment phase of the study are described.
  
  
  CONCLUSIONS
  The results of this study will uncover whether or not heavy silicone oil improves the prognosis of eyes with PVR.
authors.affiliation: Department of Ophthalmology, University of Düsseldorf, Moorenstrasse 5, Düsseldorf, Germany. joussena@googlemail.com
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Joussen
authors.forename: Bernd
authors.initials: B
authors.lastname: Kirchhof
authors.forename: Norbert
authors.initials: N
authors.lastname: Schrage
authors.forename: Christina
authors.initials: C
authors.lastname: Ocklenburg
authors.forename: Ralf-Dieter
authors.initials: RD
authors.lastname: Hilgers
mesh_terms: D006801:Humans; D018579:Patient Selection; D011379:Prognosis; D011446:Prospective Studies; D012107:Research Design; D012163:Retinal Detachment / Q000150:complications / Q000601:surgery*; D012827:Silicone Oils / Q000008:administration & dosage*; D013046:Specific Gravity; D014821:Vitrectomy; D018630:Vitreoretinopathy, Proliferative / Q000209:etiology / Q000601:surgery*; D014822:Vitreous Body
chemical_list: D012827:Silicone Oils; C515608:densiron