Effects of intravitreal injection of bevacizumab with or without anterior chamber paracentesis on intraocular pressure and peripapillary retinal nerve fiber layer thickness: a prospective study.

Purpose: To investigate the effects of intravitreal injection of bevacizumab (IVB) with or without anterior chamber paracentesis on intraocular pressure (IOP) and peripapillary retinal nerve fiber layer (PRNFL) thickness.

Methods: In this prospective randomized clinical trial, 90 eyes with center involving diabetic macular edema or wet type age-related macular degeneration (AMD) were randomly assigned to receive IVB either without (group A) or with (group B) anterior chamber paracentesis. IOP was measured before and within 2 min, 30 min, 24 hours and 3 months after injections. Peripapillary spectral-domain optical coherence tomography (SD-OCT) was performed before and 3 months after injections.

Results: Mean IOP changes 2 minutes, 30 minutes, 24 hours, and 3 months after injections were 26.4 ± 5.7 mmHg (P < 0.001), 6.5 ± 6.3 mmHg (P < 0.001), 0.2 ± 2.9 mmHg (P > 0.99) and 0.5 ± 2.4 mmHg (P > 0.99) in group A and -1.3 ± 2.4 mmHg (P < 0.001), -3.2 ± 1.8 mmHg (P < 0.001), -3.1 ± 1.8 mmHg (P < 0.001) and -1.8 ± 2.2 mmHg (P < 0.001) in group B, respectively Mean baseline average PRNFL thickness was 85.3±5.6 μm and 85.6 ± 5 μm in groups A and B respectively. Mean PRNFL thickness changes after 3 month was -2 ± 2 μm (P < 0.001) in group A and 0 ± 2 μm (P = 0.101) in group B. Mean PRNFL thickness in group A decreased more than group B (P < 0.001).

Conclusion: Conventional method of IVB injection was associated with acute IOP rise and significant PRNFL loss 3 months after injection. Anterior chamber paracentesis prevents acute IOP rise and PRNFL loss.