Early Intraocular Pressure Changes After Intravitreal Injection

Abstract

Purpose:: To evaluate intraocular pressure changes which occur during the first 15 minutes after injection of intravitreal bevacizumab.

Methods:: A retrospective chart review was performed on a consecutive series of patients that had undergone intravitreal injection of 0.05ml bevacizumab (Genentech) with measurement of intraocular pressure (IOP) over the first fifteen minutes after injection. Pre-injection anterior chamber paracentesis was not performed. IOP was checked every 1 to 2 minutes after injection until the IOP was below 30mmHg. A last value carried forward method was used to account for missing data.

Results:: 32 injections of intravitreal bevacizumab were performed in 31 eyes with multiple early measurements of IOP. 31 (97%) patients were monitored for at least 10 minutes or until IOP fell below 30mmHg. The median time for the IOP to fall below 30mmHg was 8 minutes (range 1 to over 45 minutes). Median IOP in mmHg was: 44 at 2 minutes, 40 at 4 minutes, 32 at 6 minutes, 29 at 8 minutes, 28 at 10 minutes and 25 at 15 minutes post injection. IOP was above 40mmHg in 69%, 52%, 23%, 19%, 16% and 16% of eyes at 2, 4, 6, 8, 10 and 15 minutes.Elevated IOP > 40mmHg at 15 minutes was associated with a history of glaucoma, ocular hypertension or glaucoma suspicion; higher pre-injection IOP; and weakly associated with male sex, and giving a history of ischaemic heart disease. Age and indication for bevacizumab did not appear to be associated with elevated post-injection IOP.

Conclusions:: Intravitreal injections of 0.05ml were found to be associated with large increases in IOP that can persist for over 15 minutes in 16% of patients. This finding is more common in glaucoma patients. Prolonged post-injection elevation of IOP may be of clinical importance in eyes with retinal ischaemia or glaucoma.

Keywords: injection • intraocular pressure • age-related macular degeneration