Abstract
Purpose:
To evaluate the effects of pretreatment with suprachoroidal or intravitreal triamcinolone acetonide (TA) in a subretinal endotoxin-induced model of posterior segment uveitis in New Zealand White rabbits.
Methods:
On Day 1, female rabbits (4/group) received a single unilateral injection of vehicle or 4 mg TA (Triesence®) into the suprachoroidal space (SCS) using a 33g 750µm microneedle, or a 4 mg TA IVT injection using a standard 30g needle. Intraocular pressure (IOP) was assessed prior to uveitis induction. On Day 6, each animal received a single unilateral subretinal injection of lipopolysaccharide (LPS) to induce ocular inflammation in the treated eye. Animals were monitored for 22 days following dose administration. Endpoints included body weights, ocular observations, slit lamp biomicroscopy with McDonald-Shadduck scoring and photography, indirect ophthalmoscopy, fundus photography, and histopathology.
Results:
There were no test article- or administration-related effects on mortality, body weights, ocular observations, or IOP. Following LPS injection in this endotoxin-induced uveitis model, eyes developed acute anterior and posterior segment inflammation with extensive fibrin formation in the anterior chamber and vitritis. Twenty-four hours following LPS injection, eyes that were administered either SCS vehicle or IVT TA displayed greater panuveitis than SCS TA eyes. Vitritis, aqueous flare, and cellularity were substantially less severe in both SCS and IVT TA groups of eyes compared to SCS vehicle eyes. Iris vessel dilation and tortuosity was reduced in SCS TA animals and reduced to a lesser extent in IVT TA animals when compared with the SCS vehicle group. SCS TA caused a significant reduction in inflammatory endpoints when compared with the vehicle group throughout the study. There was a marked reduction in inflammation as assessed histopathologically in eyes administered either SCS or IVT TA when compared with the vehicle group.
Conclusions:
SCS administration of 4 mg TA using a Clearside Biomedical proprietary microneedle was as effective as 4 mg IVT TA in reducing the inflammatory response in this subretinal endotoxin-induced model of panuveitis in the albino rabbit.
Keywords: 557 inflammation •
746 uveitis-clinical/animal model