Links among glaucoma, neurodegenerative, and vascular diseases of the central nervous system

Glaucoma is the leading cause of irreversible blindness worldwide. Although the intraocular pressure (IOP) has been considered for long time the key point and the only treatable risk factor of the disease, there are cases in which glaucoma continues to progress despite normal IOP values. Vision loss in glaucoma is related to a selective decrease in the number of retinal ganglion cells by apoptosis that is associated to alterations of the central visual pathways. Interestingly, similar events have been also described in disorders of the central nervous system (CNS), such as Alzheimer's disease, Parkinson's disease, Leber's hereditary optic neuropathy, and cerebrovascular diseases. In this review, we discuss recent evidence supporting pathological links between glaucoma and disorders of the CNS.