Abstract
Purpose :
Intravitreal injections of anti-VEGF agents are used for the treatment of various diseases of the posterior segment of the eye. Immediate transient elevation in IOP in normotensive eyes is a well-known side effect associated with anti-VEGF injections. The aim of this study was to determine the immediate changes in IOP levels as a function of time duration for intravitreal injections.
Methods :
The study was performed on a random selection of 16 patients receiving intravitreal bevacizumab (1.25 mg/0.05 ml) as treatment for CME. The records of patients was reviewed for age, ocular history, gender, ethnicity, phakic status, baseline IOP levels, and total number of injections. All the patients received intravitreal injections of bevacizumab (1.25mg/0.05 ml) according to medical indications. IOP was measured by rebound tonometer Icare-Pro (Icare, Finland) before intravitreal injection, 5 minutes post-injection, and repeated at 20 minutes for patients with a transient elevation in IOP of > 30 mm Hg. Duration of injection was measured in seconds.
Results :
Sixteen patients were included in the study: 6 males (38%) and 10 females (62%), ranging in age from 56 to 93 (mean age of 71.2). Fourteen (88%) were of Hispanic decent, and two (12%) were of Black descent. Nine patients were phakic (56%), six pseudophakic (38%), and one aphakic (6%). Thirteen (81%) patients received at least one prior intravitreal injection. Baseline IOP for all patients (determined from 10 prior visits) was 14.1 ± 1.06 mm Hg (95% CI). Pre-injection IOP on the day of the injection for all patients was 13.9 ± 2.27 mm Hg (95% CI). Post-injection IOP at 5 minutes was significantly elevated to 22.5 ± 4.11 (95% CI) (p=0.0008). Patients receiving intravitreal injection with a duration of less than one second demonstrated a greater transient IOP elevation (ΔIOP) at 5 minutes compared to an injection duration of greater than one second, with ΔIOPs of 16.9 ± 2.4 mm Hg and 2.1 ± 3.7 mm Hg respectively, (p=0.0004).
Conclusions :
Intravitreal injection of additional liquid volume causes significant transient IOP elevation, with a mean elevation of 8.6 ± 4.4 mm Hg (95% CI, p =0.0008) above pre-injection IOP in normotensive eyes at 5 minutes post-injection. Injection time duration of greater than one second is associated with a significant reduction in transient IOP elevation post injection.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.