Posterior vitreous detachment induced by microplasmin.
OBJECTIVE
To demonstrate the efficacy of microplasmin in inducing posterior vitreous detachment (PVD) and to evaluate the human and the feline retina after treatment.


METHODS
Thirteen human donor eyes were injected with 62.5, 125, or 188 micro g microplasmin. The 13 fellow eyes received balanced salt solution. Four of the microplasmin-treated eyes received an additional intravitreal gas injection. After incubation at 37 degrees C for 30 minutes, all globes were placed in 4% paraformaldehyde. Retinal specimens were processed for scanning (SEM) and transmission (TEM) electron microscopy. Five feline eyes were injected with 14.5- or 25- micro g microplasmin. Animals were killed after 1 day, 3 days, or 3 weeks, and retinal specimens were evaluated by electron and confocal microscopy.


RESULTS
In all control eyes, SEM demonstrated the cortical vitreous covering the inner limiting membrane (ILM). Intravitreal injection of 125 or 188 micro g microplasmin resulted in complete PVD. After treatment with 62.5 micro g microplasmin, SEM revealed collagen fibrils covering the ILM. Additional gas injection did not change the dose necessary for PVD. In vivo in cats, 25 micro g microplasmin resulted in complete PVD after 3 days. After 3 weeks, there was complete PVD with both doses of microplasmin. The retina and the ILM were well preserved in all eyes.


CONCLUSIONS
Both after death and in vivo, microplasmin induces a dose-dependent cleavage between the vitreous cortex and the ILM without morphologic alterations of the retina. In the feline eye, there is no cellular response of retinal glial cells or neurons.
Gandorfer
Arnd
A
Department of Ophthalmology, University Eye Hospital, Ludwig-Maximilians-University, Munich, Germany. arnd.gandorfer@ak-i.med.uni-muenchen.de
Rohleder
Matthias
M
Sethi
Charanjit
C
Eckle
Dominik
D
Welge-Lüssen
Ulrich
U
Kampik
Anselm
A
Luthert
Philip
P
Charteris
David
D
D000328:Adult; D000368:Aged; D000818:Animals; D002415:Cats; D004305:Dose-Response Relationship, Drug; D005341:Fibrinolysin / Q000008:administration & dosage*; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D006801:Humans; D007267:Injections; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D009457:Neuroglia / Q000187:drug effects / Q000648:ultrastructure; D010446:Peptide Fragments / Q000008:administration & dosage*; D012160:Retina / Q000187:drug effects / Q000648:ultrastructure; D013997:Time Factors; D014822:Vitreous Body / Q000187:drug effects* / Q000648:ultrastructure; D020255:Vitreous Detachment / Q000139:chemically induced* / Q000473:pathology
D005343:Fibrinolytic Agents; D010446:Peptide Fragments; C054561:microplasmin; D005341:Fibrinolysin