OBJECTIVE:To evaluate the toxicity of retinoic acid in silicone oil to the retinal tissue. METHOD:Twelve New Zealand white rabbits(24 eyes)were divided into three grorps at random. Three days after gas-compression vitrectomy,24 eyes were unedrgone gas/silicone oil exchange. The silicone oil 0.5 ml was injected intravitreally in 4 eyes as controls ,and 5mu;g/ml retinoic acid silicone oil 0.5ml in 10 eyes and 10 mu;g/ml retinoic acid silicone oil 0.5 ml in 10 eyes respectively as 2 study groups. After intravitrea[ injections, all the eyes were examined by ophthalmoscopy on the 1st, 3rd, 7th, 14th, 21st and 28th day. The retinas of the enucleated eyes on the 28th day were then examined by light microscopy and transmission electrone microscopy. RESULT: No evidence of toxicity was found in retinas after intravitreal injections of silicone oil with 5 mu;g/ml or 10 mu;g/ml retinoic acid. CONCLUSION :There was no toxic effect on the retinas by using 5 mu;g/ml or 10 mu;g/ml retinoic acid in intravitreal silicone oil tamponade operation. （Chin J Ocul Fundus Dis,1997,13: 81-82）