ENPP2 and Optic neuropathy: The results of this study showed that the mGCIPL and VD levels of patients with combined optic neuropathy were significantly lower than those of patients with simple DR, and ATX was negatively correlated with mGCIPL and VD levels, that is, with the increase of ATX levels, the thickness of mGCIPL will gradually decrease, and the vascular density will also decrease, which may be related to ATX promoting retinal inflammatory response, oxidative stress and other pathological processes.