Abstract
Purpose::
The number of intravitreal injections has exponentially increased over the past six years as new agents, such as bevacizumab, have become available. Clinicians routinely check intraocular pressure (IOP) after intravitreal injection to monitor for potentially dangerous elevations that might require treatment. To our knowledge, there has been no study of the short-term IOP trends following intravitreal injection of bevacizumab. The purpose of this study is to analyze IOP changes immediately preceding and following injection, as well as at the first follow up visit to assess the frequency of concerning IOP elevation to help determine the necessity for short-term monitoring.
Methods::
A retrospective chart review of 51 injections in 25 patients receiving intravitreal bevacizumab (1.25mg/0.05 mL) from 11/28/05 to 11/06/06 was performed. Analysis included presence of glaucoma, pre-injection IOP, post-injection IOP 20-30 minutes after injection, and IOP at the first follow-up visit. All IOP measurements were performed by Goldmann applanation tonometry. We excluded one patient with acute neovascular glaucoma who required intravitreal bevacizumab injection. Statistical analysis was performed using paired student t-test.
Results::
The average pre-injection IOP was 15.1 mmHg (range: 10-22 mmHg). The average post-injection IOP was 20.1 mmHg (range: 16-31 mmHg). This difference was statistically significant (p=0.0027). The average IOP at the first follow-up visit, which occurred an average of 25 days post injection, was 14.7 mmHg (range: 10-20 mmHg). The difference between pre-injection IOP and IOP at the first follow-up visit was not statistically significant (p=0.36). No eye in this series experienced IOP elevation severe enough to require pharmacologic or surgical treatment.
Conclusions::
Our results indicate that although patients incur a modest increase in IOP immediately following intravitreal bevacizumab injection, IOP returns to pre-injection levels at the first follow-up visit. None of the patients in our review experienced an IOP elevation severe enough to warrant treatment. Our study suggests that measuring intraocular pressure thirty minutes after intravitreal injection may not be necessary and anterior chamber paracentesis should not be performed routinely as this procedure is associated with its own risks. Shorter office visits should improve patient compliance with recurrent injections and improve clinic flow.
Keywords: injection • intraocular pressure • choroid: neovascularization