Clinicopathologic correlations of poly-(styrene-b-isobutylene-b-styrene) glaucoma drainage devices of different internal diameters in rabbits.

BACKGROUND AND OBJECTIVE: To assess the biocompatibility and intraocular pressure (IOP) lowering effect of a novel glaucoma drainage implant in rabbits. MATERIALS AND METHODS: Sixteen New Zealand white rabbits received one of three glaucoma drainage implants fabricated from poly-(styrene-b-isobutylene-b-styrene [SIBS]) with an internal diameter of the lumen of either 70 (6 eyes), 100 (6 eyes), or 150 (4 eyes) mu m. Clinical follow-up examinations were performed during 6 months and postmortem eyes were studied with light microscopy. RESULTS: Smaller internal diameter implants were associated with fewer complications. IOP levels were not statistically different among the groups. No eyes developed serious complications. Mild chronic inflammation was observed around the tube using light microscopy. CONCLUSION: SIBS glaucoma drainage implants did not produce clinically detectable intraocular inflammation in a rabbit model. The 70- and 100-mu m SIBS drainage devices demonstrated fewer postoperative complications. IOP levels were not statistically different from control eyes in all groups. [Ophthalmic Surg Lasers Imaging 2011;42:338-345.]