Alterations in intraocular pressure and ocular axial length after intravitreal Anti-VEGF injection

Abstract

Objective: To evaluate the effect of intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection on intraocular pressure (IOP) and ocular axial length (AL). Methods: A prospective series of consecutive patients undergoing injection of intravitreal bevacizumab or ranibizumab in our clinic was investigated. IOP was measured with Tono-Pen and ocular AL with ultrasound biometry before (IOP0, AL0) and about 1 min (IOP1, AL1) and 24 hours (IOP2, AL2) after intravitreal injection. Logistic regression analysis was used to investigate factors (lens status, presence of glaucoma and previous intravitreal injection) associated with increased IOP and AL. Results: We recruited 96 patients with a mean age of 66.7±12 years, 53 (55%) men and 43 (45%) women. One minute after the injection (IOP1), mean IOP increased from 15.2±3.5 mmHg (IOP0) to 22.2±8.6 mmHg (p<0.001). 24 hours after the injection, IOP decreased a mean level of 14.7±3.6 mmHg (IOP0 vs. IOP2, p˃0.05). Mean AL0, AL1 and AL2 values were 23.1± 0.82 mm, 23.25± 0.81 mm and 23± 0.8 mm, respectively. AL elongation was statistically significant just after injection (AL0 vs. AL1, p˂0.001). 24 hours after AL values were dropped below the baseline values (AL0 vs. AL2 p=0.04). Regression analysis showed a trend towards pseudophakic patients having higher IOP and AL at one minute. It was also observed that having previous intravitreal injections cause higher IOP elevation. Conclusion: Intravitreal anti-VEGF injections may lead a transient IOP elevation and AL elongation. Clinicians should consider checking IOP after intravitreal injections as a precaution. Further investigations are required to understand biometric changes after intravitreal injections.