Comparison of different biomaterials for glaucoma drainage devices

Objectives: To compare the inflammatory reaction associated with the insert ion of silicone and polypropylene endplates and endplates made of a new bio compatible polymer, Vivathane, in the rabbit subconjunctival space. Methods: Similar-sized endplates made of 3 different biomaterials were sutu red to the sclera in the superotemporal quadrant of the rabbit eye. Thirty eyes of 15 albino New Zealand rabbits were randomly assigned to the 3 group s. Conjunctival vascular hyperemia was graded in a masked fashion among gro ups. At the end of 3 weeks, the enucleated eyes were examined histologicall y and using scanning electron microscopy. Results: Polypropylene and Vivathane were associated with significantly mor e inflammation in clinical observations and based on histological grading. Silicone was associated with the least amount of inflammation. Three polypr opylene and 1 Vivathane plate were extruded between the second and third we ek. Conclusions: Silicone is the most inert of the 3 materials tested. Inflamma tion associated with biomaterials may contribute to the failure of the glau coma drainage devices. Clinical Relevance: Bleb inflammation may be related to the biomaterial bei ng used as the endplate. Endplates should be handled carefully during surge ry to avoid creating rough spots.