Glaucoma is a group of eye diseases that are characterized by progressive optic neuropathy,visual field loss and retinal ganglion cell(RGC)degeneration.It is the leading cause of irreversible blindness.High intraocular pressure(IOP)is always considered as the highest risk factor known for glaucoma,but,obviously,they are not always in parallel: there are some glaucomatous patients with optic nerve damage and visual field loss,but their intraocular pressure is normal.And the majority of people with high IOP never develop glaucoma.In the clinical trial,while IOP management is the only effective treatment,it always cannot prevent ongoing nervous damage.Therefore,there must be other risk factors than IOP for glaucoma.Based on the connection between the retina and the central visual system in the brain,we suppose that brain damage may also cause glaucoma.To check whether the visual cortex lesion would induce glaucomatous changes in the eyes,we ligated the upper branch of the middle cerebral artery to induce a visual cortex ischemia.TUNEL staining detected apoptotic cells in the RGC layer.TUNEL+anti-RBPMS co-staining demonstrated that most of the apoptotic cells were RGC cells.Anti-Brn3a staining showed that the RGC number decreased about 20%one month after the operation.More significantly,it was found that the intraocular pressure increased for about 30%after MCAO.As the changes,namely the IOP elevation and RGC loss,are crucial glaucomatous,we propose that brain lesion is also a source of glaucoma.We call it brain-source glaucoma,to distinguish it from the traditional ones caused by factors in the eyes.