Glaucomatous Injury of Central Nerve System

Glaucoma is generally considered to be a disease limited to the eye resulting from characteristic changes to the optic nerve head and corresponding visual field defects caused by elevated intraocular pressure. Therefore, the target of therapies has always been reducing intraocular pressure, supplemented by optic nerve nutritional therapy. Although glaucoma has long been recognized as an optic nerve disease, the study on the glaucomatous pathology merely reached the extracranial segment of the optic nerve, ignoring an important feature of the optic nerve, which constitutes the central nervous system (CNS). Hence, some unexplained problems in clinical practices remained, such as why the visual field impairment and optic nerve damage continue to progress with well-controlled IOP. In this section, the local optic neuropathy caused by glaucoma has been considered as part of disturbance of the whole CNS, and the concept of “integration” is introduced to discuss the characteristics of glaucomatous injury from the entire visual pathway perspective: Glaucoma is a disease impairing the whole visual pathway, which affects not only the optic ganglion cells, but also leads to the destruction of the superior neurons, which might be damaged even earlier than the ganglion cells in glaucoma; the function of not only pathway for form sense but also other sensory pathways would be affected, while the damage by glaucoma may also be associated with the reshape of the structure and function of the cortex. This section enables readers to rediscover the seemingly localized disease, glaucoma, from the integrative perspective of the visual pathway and provides new insights into the diagnosis and treatment of glaucoma in a more comprehensive way.