Abstract: Objective By studying the 33 cases of abrupt group adverse events of conjunctival hyperemia after surgery in a hospital from August 14 to September 1 in 2008, investigated the analysis method for drugs relevance of the abrupt group adverse events cases. Methods The medicines and the medical device products were investigated and analysed, and an inductive analysis was made. Results The probability of the relevance between medicines and the conjunctival hyperemia of the patients after surgery was excluded, and there was significant relevance between the medical device product, medical biodegradable chitosan preventing postsurgical adhesion, and the conjunctival hyperemia. Conclusion The abrupt group adverse events of conjunctival hyperemia was caused by medical biodegradable chitosan preventing postsurgical adhesion.

Key words: chitosan, conjunctival hyperemia, group adverse events