Central nervous system vascular disease can be combined with a variety of ocular signs, such as orbital pain, flash, visual field defects, vision loss, eye muscle paralysis. Therefore, some patients were first diagnosed in ophthalmology, including aneurysm rupture, arterial dissection, cerebral apoplexy and other critical nervous system diseases that need rapid treatment. If the doctors didn't know enough, the diagnosis and treatment might be delayed. Most of the vascular diseases of the central nervous system related to ophthalmology have clinical manifestations that cannot be explained by ophthalmology. In the face of chronic conjunctivitis, unexplained visual field defect or cranial nerve paralysis with local ineffective treatment, it is necessary to broaden the thinking of differential diagnosis. To understand the characteristics of vascular diseases of the central nervous system that are prone to ocular manifestations can provide references for the clinical diagnosis and treatment of ophthalmology.

Objective To investigate the neuroprotective effect of Benztropine on retinal ganglion cells (RGCs) death and optic nerve injury in rats model of non-arteritis anterior ischemic optic neuropathy (rNAION).Methods A total of 25 Sprague-Dawley rats were randomly divided into Benztropine treatment group (n=13)and PBS control group (n=12).The right eye was set as the experimental eye.rNAION model was established by using rose Bengal combined with laser photodynamic method.The rats in the Benztropine treatment group were received intraperitoneal injection with Benztropine 10 mg/kg (0.2 ml) daily for 3 weeks,while the rats in the PBS control group were received intraperitoneal injection with an equal volume of PBS.At 1,3 and 7 days after modeling,the retinal and optic disc conditions of the rats were observed by direct ophthalmoscopy.Retrograde labeling,fluorescence microscopy and transmission electron microscopy were used to observe the survival of RGCs and the damage of the optic nerve myelin and axon at 4 weeks after modeling.The RGCs density and survival rate of the two groups were compared by One-Way Anova.Results At 1 and 3 days after modeling,the optic disc edema was observed in the rats of rNAION model group.At 7 days after modeling,the optic disc edema decreased and the boundary was blurred compared with 3 days after modeling.After 4 weeks,the RGCs density in the PBS group was 308± 194/mm2 and the survival rate was 13.7％.The density of RGCs in the Benztropine group was 1173+868/mm2 and the survival rate was 47.6％.The differences of RGCs density and survival rate were significant between the two groups (F=7.552,8.184;P=0.015,0.012).Myelin disintegration,axon degeneration,onion-like body and gliosis were observed in the optic nerve sections of rNIAON in the PBS group,while the damage ofaxon and myelin structure in the Benztropine group was significantly less than that in the PBS group.Conclusions Benztropine group showed higher RGC survival rate,less damage ofaxon and myelin structure on rNAION model.This study explored the potential neuroprotective effect of Benztropine.