Abstract
Purpose:
Anti-VEGF intravitreal injections are the standard treatment of exudative Age-Related Macular Degeneration, and are also used for the treatment of other causes of macular edema. Due to the nature of intravitreal injections, it is expected the intraocular pressure (IOP) will increase post-injection. Yet dramatic increases in IOP can cause acute optic nerve damage. Thus, one must ensure the post-injection IOP does not reach pathologic levels. In this study, the increase in IOP after intravitreal injection of an anti-VEGF drug was measured both with and without pre-injection administration of topical brimonidine.
Methods:
Intravitreal anti-VEGF injections were performed on 33 non-glaucomatous eyes. For 23 eyes, topical brimonidine tartrate 0.2% was administered prior to injection. For 10 eyes, the injection was performed without pre-administration of topical brimonidine. Pre- and post-injection IOP's were recorded for all eyes. For eyes that were pretreated, the elapsed time between administration of the brimonidine and checking of the post-injection IOP was also recorded. Eyes that had been pretreated with brimonidine were then compared to those without pretreatment.
Results:
Of the 23 eyes pretreated with brimonidine the post-injection IOP increase ranged from 1 to 29 mmHg, with an average post-injection IOP increase of 15 mmHg. Of the 10 eyes not pretreated the post-injection IOP increase ranged from 3 to 24 mmHg, with an average IOP increase of 14 mmHg. Of the 23 pretreated eyes, an average of 15 minutes elapsed between administration of brimonidine and recording of the post-injection IOP.
Conclusions:
Intravitreal injections are expected to cause a transient increase in IOP, but care must be taken to ensure the IOP does not elevate to pathologic levels. This study was designed to evaluate if administration of brimonidine prior to injection would lessen the increase in IOP seen post-injection. In this study, there was no difference in average post-injection IOP increase seen in eyes pretreated with brimonidine versus those not pretreated. Although brimonidine has a rapid onset of action, the peak effect is not reached until 2 hours after administration. Thus, the lack of difference between the pretreated and untreated groups could be explained by the small amount of time that elapsed between pretreatment and post-injection IOP recording.
Keywords: 568 intraocular pressure