Background The introvitreal injection of triamcinolone acetonide (TA) before vitrectomy for retinal with choroidal detachment (RD/CD) can alleviate inflammatory response,but it easily lead to complications under the low intraocular pressure.The study on the efficiency and safety of subtenon injection of TA for treatment of RD/CD is lack.Objective This study was to evaluate the efficiency and safety of subtenant injection of TA with vitrectomy for treatment of RD/CD.Methods A retrospective study was adopted.The data of 22 eyes of 22patients who received subtenon injection of TA with vitrectomy for RD/CD were collected and analyzed in Affiliated Eye Hospital of Wenzhou Medical University from May 2010 to June 2014.TA of 40 mg in 0.4 ml was administered subtenantly 5 days before RD repair surgery.After initiating the treatment,the therapeutic effects on uvitis were analyzed.Intraocular pressure was monitored and CD height and range were determined by B type ultrasonography before injection and 5 days after injection respectively.In addition,blood glucose and blood pressure of the patients were evaluated.Results Ocular inflammation alleviated to some degree after TA injection in all 22 eyes.The mean intraocular pressure was (5.4±2.9) mmHg (1 mmHg =0.133 kPa) in pre-injection and (8.2±4.3) mmHg in postinjection,showing a significant difference between them (t =3.430,P ＜ 0.01).The mean maximum CD height was 5.2 (3.1,6.6)mm in pre-injection and 0.9 (0,3.8)mm in post-injection,with a significant difference between the before and after injection (Z=-4.198,P＜0.01).The mean CD range was 12 (10,12) clock before injection and 3(0,6) clock after injection,and no significant difference was found between before and after injection (all at P＞0.05) (Z=-4.124,P＜0.01).There were no statistically significant difference in the changes of blood glucose and blood pressure between before and after injection.The LogMAR visual acuities were 2.14±0.46,1.29±0.57 and 1.17±0.55 before injection and 1 month,3 months after injection,respectively,with a siginificant difference among them (F =22.060,P＜0.001).The retinal reattachment rate was 95.5 ％.Conclusions Subtenon injection of TA seems to be a good option for perisurgical management of RD/CD patients,which can alleviate uvitis,increase intraocular pressure,reduce CD height and CD range.