The effect of heparin-surface-modification on scar tissue formation around a subconjunctival polymethylmethacrylate implant in the rabbit

Abstract

Purpose: Excessive scar tissue formation around ocular drainage implants is a common cause for implant failure. The purpose of this study was to evaluate the effect of heparin-surface-modification of a subconjunctival polymethylmethacrylate implant on scar-tissue formation in the rabbit eye. Methods: Plain and heparin-surface-modified polymethylmethacrylate implants were implanted subconjunctivally in the eyes of 13 rabbits in two groups consisting of 8 and 5 animals. In the latter group the implants were in contact with aqueous humour through a fistula into the anterior chamber. Results: Both unmodified and heparin-surface-modified polymethylmethacrylate implants were well tolerated. In histological sections studied by both light microscopy and transmission electron microscopy, heparin-surface-modification of polymethylmethacrylate implants seemed to diminish the formation of scar tissue around the subconjunctival implants. Conclusion: Heparin-surface-modification of polymethylmethacrylate implants could provide one way to affect the formation of excessive fibrous tissue around ocular drainage implants.