IOP Increases, Then Decreases Within 30 Minutes of Intravitreal Bevacizumab Injection

One week after intravitreal bevacizumab injection, corneal endothelial cells showed no sign of inflammation or any other complications, according to a study published in BMC Ophthalmology.

Corneal endothelial cells make up the structure of the cornea and are located at the innermost layer. An increase in intraocular pressure (IOP) can cause corneal scarring and damage the endothelial cells, leading to significant loss of vision. If these cells are damaged, it is impossible to regenerate them.

The risks of a high IOP include the function of the endothelial pump, induced corneal edema and hypoxia, and reduced intraocular blood flow.

While some injections in the cornea can lead to increased IOP, therapeutic intravitreal bevacizumab injections increase IOP for just 30 minutes, followed by a drop to normal levels. The study analyzed the momentary changes and safety of corneal endothelial cells and corneal thickness once there is an acute increase resulting from the injection.

At Dankook University Hospital in South Korea, 42 eyes (in 42 patients) were included in the study. These eyes were treated with intravitreal bevacizumab injections to treat macula edema or macular degeneration between May 2014 and January 2015. Before each injection was completed, patients took a benchmark exam that gave baseline visual acuity and optical coherence tomography, a slit-lamp examination, and a fundus examination. In addition, IOP and endothelial cell evaluations were conducted before and after injection. Two measurements were made in the cornea to assess the density of endothelial cells (CD) and the central corneal thickness (CTT). The mean IOP was calculated by taking 3 measurements from the eye.

The results showed that there was a significant increase in IOP from baseline in all patients. Before the injection, mean IOP was 11.48 and significantly increased from 49.71 mmHg at 2 minutes to 37.64 mmHg 5 minutes after the injection. After 30 minutes, IOP returned to a normal range. After 1 week, there was no sign of inflammation in any of the 42 study participants.

There was no significant correlation in changes of CTT and CD to an increase in IOP pressure. The researchers believe that further analysis of a larger sample population is needed to measure the changing patterns of corneal endothelial cells during and after intravitreal bevacizumab injection.

“When bevacizumab is intravitreally injected, an acute increase of IOP occurs, but after 30 [minutes], the IOP normalized,” the authors wrote. “During this process, endothelial cells may receive momentary compression and stretch pressure, but it is tolerable and has no harmful effects on the corneal endothelium.”

Reference

Park J, Lee M. Short-term effects and safety of an acute increase of intraocular pressure after intravitreal bevacizumab injection on corneal endothelial cells. BMC Ophthalmol. 2018;18(1):17. doi: 10.1186/s12886-018-0682-9.