Itraconazole inhibits laser‐induced choroidal neovascularization in rats by suppressing VEGFR2 expression

Abstract

PurposeTo demonstrate the anti‐angiogenic effect of itraconazole on laser‐induced choroidal neovascularization (CNV) in rats.MethodsSix laser burns were induced in the peripapillary area of each eye of male Brown Norway rats (200–250 g) to cause CNV. Right eyes were administered intravitreal injections of 1 μg/10 μl itraconazole; left eyes received 10 μl balanced salt solution (BSS) as controls. On day 14 after laser induction, fluorescein angiography (FA) was used to assess abnormal vascular leakage. Flattened retinal pigment epithelium (RPE)‐choroid tissue complex was stained with Alexa Fluor 488‐conjugated isolectin B4 to measure the CNV area with an image analysis program. Vascular endothelial growth factor receptor 2 (VEGFR2) mRNA and protein expression were determined by quantitative RT‐PCR or Western blot.ResultsIntravitreal itraconazole significantly reduced leakage from CNV as assessed by FA and CNV area on flat mounts of the RPE‐choroid complex when compared with intravitreal BSS on day 14 after laser induction (p = 0.002 for CNV leakage, p < 0.001 for CNV area). Quantitative RT‐PCR showed significantly lower expression of VEGFR2 mRNA in RPE‐choroid complexes from itraconazole‐injected eyes than from BSS‐injected eyes (p < 0.001). Western blots indicated that VEGFR2 was downregulated after 14 days of itraconazole treatment.ConclusionsOur study demonstrated that intravitreal itraconazole significantly inhibited the development of laser‐induced CNV in rats. Itraconazole had anti‐angiogenic activity by reducing VEGFR2 expression. Itraconazole may prove beneficial for treating CNV as an alternative or adjunct to other therapies.