title: RGD peptide-assisted vitrectomy to facilitate induction of a posterior vitreous detachment: a new principle in pharmacological vitreolysis.
abstract: OBJECTIVE
  To evaluate a new concept in pharmacological vitreolysis by studying the efficacy of intravitreal RGD peptide-assisted vitrectomy in facilitating the separation of the posterior cortical vitreous from the retinal surface in an animal model.
  
  
  METHODS
  Eight rabbits (16 eyes) received an intravitreal injection of 1 or 5 mg of RGD peptide in one eye and either RGE peptide (inactive control) or phosphate buffered saline in the fellow eye. After 24 hours, a pars plana vitrectomy with low aspiration (< or =30 mmHg) was performed in an attempt to create a detachment of the posterior cortical vitreous. A masked observer performed pre- and postoperative indirect ophthalmoscopy and B-scan ultrasonography. Postoperative scanning electron microscopy evaluated the vitreoretinal surface in selected eyes. Two additional rabbits received intravitreal injections of RGD peptide in one eye (1 mg and 5 mg) and 1 mg of RGE peptide in the fellow eye to examine apoptosis of the retinal cells by TUNEL assay.
  
  
  RESULTS
  Based on postoperative ultrasound findings, six of the eight rabbits had a greater degree of posterior vitreous detachment in the RGD eye compared to the fellow eye (p = 0.03). The total number and the average number of detached quadrants in the group of RGD peptide eyes was twenty-three and 2.85 respectively compared to seven and 0.85 for the control fellow eyes (p = 0.02). Scanning electron microscopy confirmed the presence of postoperative posterior vitreous detachment. There was no evidence of retinal cell apoptosis in RGD injected eyes.
  
  
  CONCLUSIONS
  RGD peptide-assisted vitrectomy facilitated posterior vitreous detachment in rabbit eyes, suggesting that RGD-containing peptides may prove to be effective adjuncts in producing posterior vitreous separation during vitreous surgery.
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, NC 27710, USA.
authors.forename: Leonardo B
authors.initials: LB
authors.lastname: Oliveira
authors.forename: Carsten H
authors.initials: CH
authors.lastname: Meyer
authors.forename: Janardan
authors.initials: J
authors.lastname: Kumar
authors.forename: Misako
authors.initials: M
authors.lastname: Tatebayashi
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Toth
authors.forename: Fulton
authors.initials: F
authors.lastname: Wong
authors.forename: David L
authors.initials: DL
authors.lastname: Epstein
authors.forename: Brooks W
authors.initials: BW
authors.lastname: McCuen
mesh_terms: D000818:Animals; D017209:Apoptosis; D020287:In Situ Nick-End Labeling; D008855:Microscopy, Electron, Scanning; D009842:Oligopeptides / Q000627:therapeutic use*; D011817:Rabbits; D014463:Ultrasonography; D014821:Vitrectomy / Q000379:methods*; D020255:Vitreous Detachment / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology
chemical_list: D009842:Oligopeptides; C047981:arginyl-glycyl-aspartic acid