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Microplasmin intravitreal administration in patients with vitreomacular traction scheduled for vitrectomy: the MIVI I
Marc D de Smet1, Arnd Gandorfer, Peter Stalmans
1Department of Ophthalmology, ZNA Middelheim Campus, Antwerp, Belgium. mddesmet1@mac.com
Purpose:
To evaluate the safety and preliminary efficacy of 4 doses and several exposure times of intravitreal microplasmin given before pars plana vitrectomy for vitreomacular traction maculopathy.
Design:
A multicenter, prospective, uncontrolled, dose-escalation, phase I/II clinical trial.
Participants:
Sixty patients enrolled into 6 successive cohorts.
Intervention:
A single intravitreal injection of microplasmin at 1 of 4 doses (25, 50, 75, or 125 microg in 100 microl) administered either 1 to 2 hours, 24 hours, or 7 days before planned pars plana vitrectomy.
Main Outcome Measures:
For safety, a complete ophthalmologic examination, fundus photography, fluorescein angiography, Humphrey visual fields, and electrophysiology; for efficacy, posterior vitreous detachment (PVD) induction as assessed by B-scan ultrasound and ease of PVD induction at the time of vitrectomy.
Results:
The use of microplasmin led to a progressively higher incidence of PVD induction on ultrasonography with increasing time exposure. A PVD before surgery was observed with 25 microg microplasmin in 0, 2, and 5 patients with increasing exposures (2 hours, 24 hours, 7 days). With increasing dose, a PVD before surgery was observed by ultrasound as follows: 25 microg, 0; 50 microg, 1; 75 microg, 2; 125 microg, 3. However, at surgery, with a 125-microg dose, these patients had a discontinuous layer of vitreous present on the retinal surface resulting from the induction of an anomalous PVD in the form of vitreoschisis. One retinal detachment developed shortly after administration of microplasmin. Two developed after surgery. There were no other safety concerns.
Conclusions:
Results from this initial clinical trial evaluating intravitreal microplasmin show the drug to be well tolerated and capable of inducing a pharmacologic PVD in some patients. These results warrant evaluation of microplasmin in larger, controlled trials.
Insights
Intravitreal microplasmin demonstrated safety and efficacy in inducing posterior vitreous detachment (PVD) before vitrectomy for vitreomacular traction. Further controlled trials are warranted to confirm these promising results for PVD induction.
Area of Science:
- Ophthalmology
- Retinal Surgery
- Pharmacology
Background:
- Vitreomacular traction maculopathy is a condition affecting vision.
- Pars plana vitrectomy is a surgical treatment for this condition.
- Pharmacologic induction of posterior vitreous detachment (PVD) may offer an alternative or adjunct to surgery.
Purpose of the Study:
- To assess the safety and preliminary efficacy of intravitreal microplasmin.
- To evaluate different doses and exposure times of microplasmin.
- To determine its potential for inducing PVD before pars plana vitrectomy.
Main Methods:
- A multicenter, prospective, uncontrolled, dose-escalation, phase I/II clinical trial.
- Sixty patients received intravitreal microplasmin at doses of 25, 50, 75, or 125 microg.
- Injections were administered 1-2 hours, 24 hours, or 7 days before vitrectomy.
Main Results:
- Microplasmin administration showed a dose- and time-dependent increase in PVD induction.
- Anomalous PVD (vitroschisis) occurred at the highest dose.
- One retinal detachment occurred post-administration, and two post-surgery; no other safety concerns were noted.
Conclusions:
- Intravitreal microplasmin appears well-tolerated.
- The drug can pharmacologically induce PVD in some patients.
- Larger, controlled trials are recommended to further evaluate microplasmin.
