[Optical coherence tomography angiography (OCT-A) and the (non-glaucomatous) optic nerve]

Optical coherence tomography angiography (OCTA) is a non-invasive, reliable, repeatable exam. As opposed to fluorescein angiography, OCTA allows analysis of the capillary bed without interference from diffusion phenomena. It is now widely used for both the diagnosis and ongoing care of retinal and choroidal diseases. However, its use is still limited for evaluation of the optic nerve. Recently, new data quantification software can add value to macular and papillary vascularization images. This review details OCTA results in the most important optic nerve conditions, whether acquired or congenital, other than glaucoma. In most cases, OCTA shows modifications of the retinal or papillary vascularization systematically impacting retinal nerve fibers, ganglion cells layer and visual acuity. OCTA contributes to a better understanding of the pathophysiology of optic nerve disease without being able to specify yet whether the modifications cause or are caused by the disease. OCTA is particularly useful for neuro-ophthalmology. In addition to detection and diagnosis, OCTA can be used for follow-up and monitoring of treatment response.