The authors evaluated optical coherence tomography (OCT) angiography in 10 patients who suffered various types of chronic optic neuropathies. Glaucoma is known to cause a decrease in peripapillary perfused capillary density on OCT angiography. However, other optic neuropathies have not been explored in this way to see if these changes are specific to glaucoma. OCT angiography allows visualisation of the peripheral capillary network, which is not visible on standard fluorescein angiography. The results of this study found that all chronic optic neuropathies with retinal nerve fibre layer thinning and visual field defects have a decrease in the peripapillary capillary density on OCT angiography, that corresponds to the retinal nerve fibre layer (RNFL) thinning seen on standard OCT. This provides evidence that reductions in peripapillary capillary flow density captured on OCT angiography in many optic neuropathies, including glaucoma, are secondary to optic nerve (and RNFL) damage, rather than the primary cause of the optic neuropathy.