Purpose: Brimonidine (0.15%), which is used to lower intraocular pressure, is an α-2-adrenergic agonist that has vasoconstrictive effects. This study examined whether the administration of brimonidine (0.15%) before intravitreal injection prevents subconjunctival hemorrhage.
Methods: A prospective, randomized, double-masked single-center study. Two hundred and forty-four patients (244 eyes) who underwent intravitreal injection were prospectively examined. The control group (118 eyes) was given normal saline, while the experimental group received 0.15% brimonidine (126 eyes) 30 minutes before the intravitreal injection. On Days 1 and 7, the treatment outcome was assessed using slit-lamp microscopy. The severity of subconjunctival hemorrhage was scored on a scale of 1 (mild) to 3 (severe). To determine the size of the affected area, the lengths of the short and long axes of the subconjunctival hemorrhage were measured in millimeters and then multiplied. To consider both the severity and the size of subconjunctival hemorrhage, the severity score was multiplied by the size of the subconjunctival hemorrhage.
Results: Subconjunctival hemorrhage occurred as a result of intravitreal injection in 13.5% (17 eyes) of the brimonidine group and in 29.7% (35 eyes) of the control group (P = 0.003). On Days 1 and 7, the severity and size of the subconjunctival hemorrhage and the product of these 2 parameters were significantly lower in the brimonidine group.
Conclusion: The administration of 0.15% brimonidine before an intravitreal injection decreased the incidence, severity, and size of subconjunctival hemorrhage.