Influence of axial length and postinjection reflux on sustained intraocular pressure elevation as a result of intravitreal anti-vascular endothelial growth factor therapy
PURPOSE: To assess an association of axial length (AL) or postinjection reflux with transient or sustained intraocular pressure (IOP) elevation in patients with neovascular age-related macular degeneration receiving anti-vascular endothelial growth factor injections. METHODS: One hundred and forty-seven eyes from 74 consecutive patients with neovascular age-related macular degeneration who presented to a single physician over a 2-month period had ALs measured by IOLMaster. Twenty-one patients had preinjection and immediate postinjection IOP measured and immediate reflux assessed. RESULTS: Overall, 9.5% of eyes had been identified with sustained IOP elevation in our previous study. Axial length did not significantly differ between eyes that had (AL, 23.96 +/- 0.66 mm; n = 14) and had not experienced sustained IOP elevation (AL, 23.44 +/- 1.24 mm; n = 133; P = 0.12, t-test). By linear regression analysis, the relationship between experiencing sustained IOP elevation and AL was not statistically significant (R(2) = 0.0165; P = 0.121). The relationship between AL and immediate postinjection IOP elevation was also not statistically significant (R(2) = 0.0001; P = 0.97). Immediate postinjection IOP increase did differ between eyes without reflux (30.2 +/- 9.3 mmHg; n = 12) and those with reflux (1.1 +/- 7.2; n = 9; P < 0.001). CONCLUSION: Axial length does not seem to be a predictor of transient or sustained IOP elevation. Repeated trabecular meshwork trauma related to the absence or presence of reflux and immediate postinjection IOP elevation may be a contributing factor.