Purpose: Inhibition of VEGF is widely used in patients to control neovascularization and decrease vascular permeability. To date, the effect of VEGF inhibition has not been evaluated in the developing retina such as that seen in premature infants. The goal of this study was to address the effect of anti-VEGF treatment on retinal development of a mouse model of retinopathy.
Methods: C57BL/6J mice were evaluated using a model of oxygen-induced retinopathy. Test animals were treated at postnatal day (P) 14 with intravitreal injections of the VEGF inhibitor aflibercept (2.5 or 10 μg) in one eye. Control animals were treated with injection of PBS in one eye. The noninjected fellow eyes were used as internal controls. Areas of avascular retina and neovascular tufts in injected (treated) eyes and noninjected fellow eyes were determined at P17, and the difference related to these characteristics was obtained among them. To evaluate the effect of VEGF inhibition on neurogenesis, focal ERG was performed at P21 and P42. Histologic evaluation of the retinal structure was also evaluated at P42.
Results: Aflibercept treatment reduced the amount of neovascular tufts but significantly increased the area of avascular retina (low dose and high dose) at P17. The delayed vascular growth corresponded to decreased ERG amplitudes (at P21 and P42) and structural changes in the retinal layers that persisted (at P42), despite vascular recovery.
Conclusions: Inhibition of VEGF in developing eyes has the short-term effect of delayed vascular growth and the long-term effects of decreased function with persistent changes in the neuroretinal structures.
Keywords: VEGF; aflibercept; anti-VEGF; neurovascular niche; retinopathy of prematurity.