Intraocular pressure measurements following intravitreal anti-vascular endothelial growth factor injections with and without the use of a Honan balloon : a randomised open label clinical trial

Abstract

OBJECTIVE : To assess whether ocular compression preintravitreal bevacizumab injection is beneficial in reducing the post-intravitreal injection intraocular pressure (IOP). METHOD : A prospective randomised, two-arm parallel control trial, at a secondary care ophthalmology clinic (Witbank Provincial Hospital) was conducted. Fifty-six patients receiving intravitreal injections of 0.1 ml bevacizumab (Avastin, Genentech, Roche, Basel, Switzerland) were randomised to either receive no intraocular pressure-lowering intervention pre-injection, or to receive intraocular pressure-lowering intervention pre-injection with the application of a Honan balloon inflated to 20–30 mmHg and applied over the eye for 15 minutes. After the administration of intravitreal injection in either group, the patients’ intraocular pressures were measured at 5-, 10- and 30-minute intervals using the Goldmann applanation tonometer. RESULTS : Twenty-eight patients were enrolled in each of the intervention and control arms of the study. The median baseline IOPs were 14 mmHg (IQR: 11–18 mmHg) and 14 mmHg (IQR: 12–16.5 mmHg) (p=0.914) in the control and intervention group respectively. The median IOPs in the control and intervention groups at 5-, 10- and 30-minutes respectively were 36 mmHg (IQR: 33–38 mmHg) and 18 mmHg (IQR: 16–24 mmHg) (p<0.001); 29 mmHg (26–30 mmHg) and 18 mmHg (14–20 mmHg) (p<0.001); and 24 mmHg (20–26 mmHg) and 18 (12–18 mmHg) (p<0.001). CONCLUSION : The results demonstrate a significant reduction in the post-injection IOP rise with the use of a Honan balloon to reduce IOP prior to the administration of intravitreal injections. Based on the findings of this study it is recommended that the Honan balloon be used prior to intravitreal injections in patients with normal pre-injection IOPs.