Purpose: To evaluate the clinical outcomes and biologic effects on the aqueous humor concentrations of vascular endothelial growth factor (VEGF) in patients with neovascular glaucoma (NVG) treated with intravitreal bevacizumab (IVB).
Methods: Twenty-nine consecutive patients (35 eyes) treated with 1.0- or 0.1-mg injections of IVB for NVG between January and December 2009 were enrolled in this retrospective, interventional pilot study. The visual prognosis and changes in intraocular pressure (IOP) were followed for >6 months after the initial injection. Aqueous humor samples were obtained at the initial IVB injection from all study eyes and 1 week after the first injection in eyes undergoing a second intervention to measure the VEGF concentration.
Results: The VEGF concentrations in the 35 eyes significantly correlated (r=0.535, P<0.001) with the pretreatment IOP. The mean reductions of the VEGF levels 1 week after IVB did not differ significantly between the 1.0- and 0.1-mg groups (P=0.738). Despite more repeated injections in the 0.1-mg group and additional medical or surgical interventions in both groups, both dosages inhibited the neovascular activity. The ability to control the IOP after IVB did not differ significantly between groups at 1 week (P=0.625) and 6 months (P>0.99). Visual improvements also did not differ significantly between groups during the 6-month follow-up (P=0.437).
Conclusions: Aqueous humor levels of VEGF were significantly correlated with the IOP. Low-dose (0.1 mg) IVB was as effective as the currently used higher dose (1.0 mg) for treating NVG within at least 6 months after the initial injection.