NORMAL TENSION GLAUCOMA

Normal-tension glaucoma, also known as low-tension glaucoma, is characterized by progressive optic nerve damage and visual field loss with a statistically normal intraocular pressure. This form of glaucoma, which is being increasingly recognized, may account for as many as one-third of the cases of open-angle glaucoma in the United States.

Normal-tension glaucoma is thought to be related, at least in part, to poor blood flow to the optic nerve, which leads to death of the cells which carry impulses from the retina to the brain. In addition, these eyes appear to be susceptible to pressure-related damage even in the high normal range, and therefore a pressure lower than normal is often necessary to prevent further visual loss.

Research in the field of optic nerve blood flow and its role in glaucoma is a source of much excitement at the present time and, hopefully, will lead to new methods of treating this disorder. Since the best therapy for normal-tension glaucoma is largely unknown, much attention is being given to a study known as the International Collaborative Low Tension Glaucoma Protocol.