Abstract
Purpose: :
Bioresorbable microparticles provide a promising platform for sustained delivery of therapeutics to the eye. Limited ocular safety data is available for non-drug containing microspheres. Two 90-day rabbit studies were conducted to obtain basic ocular safety data for poly(lactide-co-glycolide) microspheres administered after subconjunctival (SC) or intravitreal (IV) injection in New Zealand White rabbits.
Methods: :
Microspheres with discrete size ranges (<20µm to >100µm) were prepared. Variables tested included particle size, mass loading and injection vehicles. Bilateral 50µL injections were administered by subconjunctival or intravitreal injection. Data collection included ocular observations, intraocular pressures, fundus photography (IV only), ERG (IV only) and OCT (IV only).
Results: :
Initial mild to moderate observations of conjunctival discharge, swelling and inflammation were observed due to the injection procedure which resolved within the first eight days. No significant tolerability observations were seen in the remainder of the study. Intraocular pressures were transiently elevated and normalized quickly.
Conclusions: :
Both subconjunctival and intravitreal injections of non-drug loaded microspheres were well tolerated over 90 days. Initial conjunctival observations related to the injection and transient IOP elevation for IV administration were noted but rapidly dissipated.
Keywords: vitreous • retina • sclera