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.