[Preliminary report on prevention of adhesion after orbital trauma by chitosan membrane].

ABSTRACT

OBJECTIVE: To study the result and the mechanism of preventing postoperative adhesion after orbit trauma by chitosan membrane, and to observe the effects of chitosan membrane on optic nerve and visual function. METHODS: It was a self-control trail. Ten white rabbits (twenty eyes) were adopted in this experiment. Right eye on each rabbit was used in chitosan membrane experiment group and the left eye in control group. Trauma was made between superior rectus muscle and corresponding periosteum. Chitosan membrane was implanted between trauma tissues in the experimental group. F-VEP was tested 1 day before the operation and 6 days after operation in each rabbits. Degree of adhesion was evaluated by naked eyes; inflammatory score was evaluated by pathological examination and TGF-p3 impression was evaluated by immunohistochemical studies. RESULTS: F-VEP examination 6 days after the operation showed that the wave amplitude of Pt1 was (9.847 +/- 2.320) mV, latency of P1 was (71.700 +/- 5.144) ms. There was no difference between pre- and post-operative data (t = 0.974, 0.228; P > 0.01). Adhesion degree evaluation showed that there were 7 eyes with 1 score, 3 eyes with 2 score in the experimental group; while there were 1 eye with 2 score, 5 eyes with 3 score, 4 eyes with 4 score in the control group. There was a statistically significant difference (T = 59.00, P < 0.01) in adhesion degree between experimental group and control group. A statistically significant difference was presented in pathologic sheet score between the experimental and control groups. There were 6 eyes with 1 score, 4 eyes with 2 score in experimental group; while 2 eyes with 1 score, 4 eyes with 2 score, 4 eyes with 3 score in the control group. Immunohistochemical study showed strong positive in all slides of the experimental group, while only weakly positive in the control group. CONCLUSION: Chitosan membrane is effective on decreasing the synthesis of collagen fibrils and preventing adhesion after the orbit trauma in the rabbits.