To assess whether a 4 mg/0.05 ml intravitreal triamcinolone acetonide injection can reduce the IOP elevation compared to conventional 4 mg/0.1 ml injection.

A retrospective case study was performed in 48 patients (48 eyes) who received intravitreal triamcinolone acetonide injection and who had a minimum follow-up time of six months. Patients were randomly assigned to receive 4 mg/0.1 ml or 4 mg/0.05 ml (24 patients in each group).

Before injection, mean IOP was 13.8±2.2 mmHg and 13.9±2.4 mmHg in the 0.1 ml and 0.05 ml group. The difference in IOP elevation between the two groups was statistically significant immediately after injection ( P =0.000), one hour after injection ( P =0.001), and one day after injection ( P =0.000). After injection, the central macular thickness decreased significantly the of two groups. The difference of the central macular thickness decrease between both groups was not statistically significant.

An intravitreal triamcinolone acetonide 4 mg/0.05 ml injection will more quickly reduce the IOP elevation in the early phase compared to 4 mg/0.1 ml injection, while providing a similar effect on the change of central macular thickness.