Abstract
Purpose::
Intravitreal pharmacotherapy has become a commonly performed office procedure for patients with retina disorders. Severe elevation of intraocular pressure (IOP) in the immediate post-injection period has been a concern resulting in paracenthesis being advocated by some physicians. This study evaluates the IOP rise within the first 60 minutes of intravitreal drug injection.
Methods::
32 eyes of 32 patients underwent intravitreal injection (0.05 ml to 0.15 ml). Post-injection intraocular pressure was measured at 3 minutes intervals until minute 15, then at minute 30 and 60. Optic disc perfusion was inspected immediately after injection and at 15, 30, and 60 minutes.
Results::
The mean IOP was 16.1 mmHg preinjection, 42.3 mmHg immediately post-injection, 34.1 mmHg at minute 3, 28.5 mmHg at minute 6, 25.0 mmHg at minute 9, 23.8 mmHg at minute 12, 22.6 mmHg at minute 15, 20.5 mmHg at minute 30, and 18.3 mmHg at minute 60.For the 0.05 ml group, the mean IOP was 16.4 mmHg preinjection, 38.9 mmHg immediately post-injection, 31.5 mmHg at minute 3, 26.6 mmHg at minute 6, 23.6 mmHg at minute 9, 22.4 mmHg at minute 12, 20.9 mmHg at minute 15, 19.4 mmHg at minute 30, and 18.0 mmHg at minute 60.For the 0.15 ml group, the mean IOP was 15.7 mmHg preinjection, 53.5 mmHg immediately post-injection, 43.8 mmHg at minute 3, 36.8 mmHg at minute 6, 30.6 mmHg at minute 9, 29.4 mmHg at minute 12, 28.7 mmHg at minute 15, 24.4 mmHg at minute 30, and 19.7 mmHg at minute 60.Immediately post-injection the optic disc was well perfused in 19 (59%), pulsatile in 12 (38%) and underperfused in 1 (3%) eyes. At minute 15 the optic nerve was well perfused in 29 (91%), pulsatile in 3 (9%), and underperfused in 0 eyes.None of the subjects required a paracenthesis in order to reduce the IOP.
Conclusions::
Intraocular pressure returns to a safe level within 15 minutes of intravitreal injection. Early IOP readings may result in false alarm and subsequent paracenthesis. Measuring IOP 10 minutes after intravitreal injection provides a safe and efficient protocol for identifying those patients at risk of significantly elevated IOP. Routine paracenthesis for the prevention of IOP elevation does not appear warranted.
Keywords: age-related macular degeneration • diabetic retinopathy • intraocular pressure