RGD peptide-assisted vitrectomy to facilitate induction of a posterior vitreous detachment: a new principle in pharmacological vitreolysis.
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.
Oliveira
Leonardo B
LB
Department of Ophthalmology, Duke University Medical Center, NC 27710, USA.
Meyer
Carsten H
CH
Kumar
Janardan
J
Tatebayashi
Misako
M
Toth
Cynthia A
CA
Wong
Fulton
F
Epstein
David L
DL
McCuen
Brooks W
BW
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
D009842:Oligopeptides; C047981:arginyl-glycyl-aspartic acid