Purpose:
To evaluate the safety profile of a Brimonidine impregnated extended release intravitreal implant, in a normotensive rabbit eye.
Methods:
Implants were made from hollow poly-l- lactic acid (PLA) tubes 0.36mm in diameter impregnated with Brimonidine pamoate, coated with 10% PVA solution and were preloaded in 25 gauge injector. Each filled PLA implant contained 100 micrograms of Brimonidine pamoate. Drug impregnated implants were injected in the vitreous cavity of one eye of 12 New Zealand Pigmented rabbits whereas other eye was injected with a sham implant for control. Investigators were masked to the identity of the eye with drug implant.An ocular examination was conducted at baseline including intraocular pressure measurement, dilated fundus examination and electro-retinogram (ERG). Same examination was repeated at 4 weeks for all rabbits. All rabbits were monitored closely for ocular complications. Baseline ERG was compared with ERG at 4 weeks using ANOVA.
Results:
No complications were reported from either eye of any rabbits over a 4-week period. There was no difference in the IOP measurements and ERG values between the baseline and at 4 weeks in either eye. Table 1 presents ERG data at baseline and at 4 weeks.
Conclusions:
Brimonidine impregnated extended release intravitreal device was found to be safe in normotensive rabbit eyes up to 1 month. Longer duration studies are ongoing.
Keywords: injection • vitreous • electrophysiology: non-clinical