Abstract
Purpose: :
The intracameral (IC) injection of medications during intraocular surgery has been proposed as an approach to decrease the need for post-operative topical drops. Unfortunately, medications injected into the anterior chamber (AC) are promptly cleared. Microparticles, which can be used to deliver medications in a long-term fashion, can be retained in the AC for extended periods of time. However, the introduction of foreign bodies, such as these particles, can induce AC inflammation. The purpose of this study was to determine if coating particles with poly(ethylene glycol) (PEG) can limit inflammation following IC injection.
Methods: :
Fifteen rabbit eyes were used in this study. Slit-lamp exam was performed to verify that no AC inflammation was present at baseline. The animals in experimental groups received IC injections of a particle suspension and those in the control group received an IC injection of saline. Groups included: Control- 100 µL of saline; Uncoated- 100 µL of 1 µm uncoated latex particles; and Coated- 100 µL of 1µm PEG coated latex particles. Slit-lamp examination was performed on days 1,7,14 and 30 following injection; AC inflammation was quantified using a clinical uveitis scale that scored AC cells, flare and fibrin.
Results: :
AC inflammation was detected in all groups at day 1 and the scores were: Uncoated- 7.0, Coated- 5.4 and Control- 5.2. The inflammation in all groups declined after day 1, and at day 30 the scores were: Uncoated- 2.6, Coated- 1.4 and Control- 1.3. There was no significant difference in AC inflammation scores of the Coated and Control (saline) groups at any point; the AC inflammation of the Uncoated group was significantly greater than both Coated and Control groups at all time points (P<0.05).
Conclusions: :
AC inflammation associated with IC injection of microparticles can be decreased when the particles are coated with PEG. Coated particles may be useful for sustained delivery of post-operative medications.