To investigate the occurrence and increase in intraocular pressure (IOP) over time in patients with retinal vein occlusion treated with dexamethasone intravitreal implants.

Thirty-two patients who met retreatment eligibility criteria received sequential intravitreal dexamethasone implant insertion for retinal vein occlusion in one eye, and were followed for 36 months (maximum of 10 injections) from February 2011 to March 2017. Patients without follow-up data at each investigation time point were excluded.

An IOP increase ≥ 10 mmHg from baseline or an IOP ≥ 25 mmHg occurred in 18.8% of the patients. IOP-lowering medications were used in these patients. The first IOP elevation occurred with a mean of 5.9 months after the first intravitreal dexamethasone implant insertion in the IOP elevation group, and with a mean of 1.5 months after previous intravitreal dexamethasone implant insertion in each IOP elevation event. No patients required laser or incisional glaucoma surgery during the study period.

An increase in IOP occurred in the early period after intravitreal dexamethasone implant insertion, and did not occur in sequential insertion. Although an increase in IOP was a significant side effect of intravitreal dexamethasone implant insertion, the IOP could be controlled with careful observation and use of preliminary and therapeutic anti-ocular hypertensive agents.