Objective    To evaluate the effect of implantation of chitosan membrane with triamcinolone（TA） into perichoroidal space combined with intraocular vancomycin injection on the protection of retina in rabbit endophthalmitis.     Methods    The drug membrane was made of gelatin-chitosan. The right eyes of 30 normal pigment rabbits were inoculated intravitreally with 0.1 ml mixture

of 10

5

CFU standard strain Staphylococcus aureus (ATCC 25923). Twenty-four hours later

rabbits were equally randomized to intravitreal vancomycin group (Group A)

intravitreal vancomycin and TA eye dropping (Group B)

and intravitreal vancomycin combined with TA membrane implantation (Group C). Clinical observation of ocular fundus was done every day with indirect ophthalmofundoscope. B ultrasound examination was carried out in 24 h after inoculation and on the 14th day after therapy. Electroretinogram (ERG) was done before therapy and the 14th day after therapy. Histopathologic grading and electron microscopy were carried out at the 14th day.     Results     After implanting the drug membrane into perichoroidal space

the inflammation in group C was markedly less than the other 2 groups

and its inflammation score  was significantly lowest (P0.05). Retinal detachment occurred less in the group C than in the other 2 groups. ERG demonstrated that dark adaptation b wave amplitude before the treatment was dropped more dramatically in groups A and B than those after treatment

but there was no difference in group C before and after the treatment. Significant difference was found in the wave amplitude after the treatment between groups A and B

groups B and C

and groups A and C. Electron microscopy shows that the retinal pigment epithelium(RPE) structure of group C was intact and cellular organs well-arranged. There was no statistical difference between groups A and B in histopathologic grading.     Conclusion    Implantation of chitosan membrane with TA into perichoroidal space combined with intraocular vancomycin injection can protect the retina during the treatment course of endophthalmitis.