PVD following plasmin but not hyaluronidase: implications for combination pharmacologic vitreolysis therapy.
OBJECTIVE
To study whether intravitreal injection of plasmin + hyaluronidase safely induces posterior vitreous detachment (PVD).


METHODS
Rabbits were randomized into three groups: (A) 20 rabbits, intravitreal injection of plasmin 1 U + hyaluronidase 20 U in balanced salt solution (BSS) 0.1 mL into one eye; (B) 12 rabbits, plasmin alone; (C) 12 rabbits, hyaluronidase alone. The fellow eye of each rabbit was injected BSS 0.1 mL. In Group A, scanning electron microscopy (SEM) was done in four rabbits at 0.5 hour and in four rabbits at 1 hour. After 7 days, all the remaining 36 rabbits received electroretinography, SEM was examined in eight of each group, and immunohistochemistry was done in four of each group.


RESULTS
SEM disclosed the eyes of Group A had complete PVD (8/8), Group B partial PVD (7/8), and Group C (8/8) and all the control eyes (24/24) no PVD after 7 days. Partial PVD was found in 4/4 at 0.5 hour and complete PVD was seen in 3/4 at 1 hour in Group A. Immunohistochemistry showed that the amounts of laminin and fibronectin in the vitreoretinal interface were decreased in Group A and B versus the control eyes (P <0.001), but not in Group C versus the control eyes (P >0.05). Electroretinography showed no changes in any group (P >0.05).


CONCLUSIONS
Vitreous injection of plasmin + hyaluronidase induced complete PVD with no obvious toxicity. Plasmin induced partial PVD, but hyaluronidase had no effects.
Wang
Zhi-Liang
ZL
Department of Ophthalmology, Shanghai First People's Hospital, People's Republic of China. wzl721@sina.com
Zhang
Xi
X
Xu
Xun
X
Sun
Xiao-Dong
XD
Wang
Fang
F
D000818:Animals; D001485:Basement Membrane / Q000378:metabolism / Q000648:ultrastructure; D003131:Combined Modality Therapy; D004596:Electroretinography; D005341:Fibrinolysin / Q000627:therapeutic use*; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D005353:Fibronectins / Q000378:metabolism; D006821:Hyaluronoglucosaminidase / Q000627:therapeutic use*; D007150:Immunohistochemistry; D007267:Injections; D007797:Laminin / Q000378:metabolism; D008297:Male; D008855:Microscopy, Electron, Scanning; D011817:Rabbits; D014821:Vitrectomy; D014822:Vitreous Body / Q000187:drug effects*; D020255:Vitreous Detachment / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology
D005343:Fibrinolytic Agents; D005353:Fibronectins; D007797:Laminin; D006821:Hyaluronoglucosaminidase; D005341:Fibrinolysin