Background: The results regarding changes of choroidal thickness following intravitreal ranibizumab injections in the literature are controversial. Vascular endothelial growth factor A is implicated in pathogenesis of neovascular age-related macular degeneration (AMD). The suspected unchanged choroidal layer thickness after intravitreal injections of ranibizumab suggests a possible protection of the outer blood-retinal barrier in the human eye.
Objective: The aim was to evaluate choroidal thickness following the first administration of the study drug ranibizumab into the eyes of naïve wet AMD patients (nAMD).
Methods: In this open label, 3-month, prospective, single-center, interventional, single-arm pilot study, 20 nAMD eyes were included and underwent three consecutive monthly injections of ranibizumab (0.5 mg/0.05 ml). Vital signs (i.e., blood pressure and pulse), ophthalmic examinations, intraocular pressure, best correct visual acuity and subfoveal choroidal thickness as examined with optical coherence tomography using enhanced depth imaging (OCT-EDI) were assessed at each visit. All patients were evaluated at baseline and at 15, 30 60 and 90 days after intravitreal injection. Ten eyes with fibrotic AMD lesions were evaluated as the control group.
Results: In all eyes, the choroidal thicknesses (µm) exhibited no significant changes from the baseline visit to the visits at 15, 30, 60 and 90 days post-injection (P > 0.05). The intravitreal treatment with ranibizumab was well tolerated, and no adverse events were registered.
Conclusion: Choroidal thickness appeared to be unmodified following the intravitreal injection of ranibizumab into nAMD eyes. Intravitreal ranibizumab injections probably elicit a pharmacologic effect only in the choroidal neovascularization and not in the choroid circulation under neovascular lesions. Clinical Trials Eudract Registration #: 2013-005091-17.