To study the risk factors of increased intraocular pressure (IOP) response to triamcinolone acetonide intravitreal (IVTA) injection in eyes with macular edema associated with retinal vein occlusion.Eighty-nine eyes with macular edema associated with retinal vein occlusion first received periocular injection of 40 mg triamcinolone acetonide (TA) and were followed for one month. According to the diversity of IOP after periocular TA (PTA) injection, they were divided into the elevation IOP group (group A, 26 eyes) and the normal IOP group (group B, 63 eyes). They then received 4 mg TA intravitreal injection. IOP measurements were recorded after PTA and IVTA injections, and were followed for six months.Both PTA and IVTA injections caused a rise in IOP, but it was higher in the IVTA injection (40.45%) than in the PTA injection (29.21%). The mean rise in IOP was more significant in eyes with IVTA injection (28.08 ± 8.24 mmHg) than in eyes with PTA injection (20.87 ± 4.07 mmHg). Patients with an elevation IOP above 6 mmHg after PTA injection had a 73.08% chance of developing a pressure of 24 mmHg or higher, whereas only 12.70% of those with an elevation IOP below 6 mmHg after PTA injection experienced pressure elevation.IOP response to PTA injection is a good way to judge IOP response to IVTA. If the patient is highly sensitive to corticosteroid, treatments other than IVTA injection are used to avoid the increased risks associated with intravitreal corticosteroid injection.