Glaucoma resulting in optic nerve damage and vision loss, and may be mild or severe. It can be due to an eye injury, inflammation, a tumor, or advanced cases of cataracts or diabetes. It can also be caused by certain drugs such as steroids. Treatment depends on whether it is open-angle or angle-closure glaucoma. In pseudoexfoliation glaucoma (also, "PEX", "exfoliation glaucoma") the pressure is due to the accumulation of microscopic granular protein fibers, which can block normal drainage of the aqueous humor. PEX is prevalent in Scandinavia, primarily in those over 70, and more commonly in women. Pigmentary glaucoma (also, pigmentary
Normal tension glaucoma of cases that have been reported in medical literature in the 1980s and 1990s who had the typical signs of glaucomatous damage, like optic nerve head excavation and thinning of the retinal nerve fiber layer, while these patients had an IOP that would generally have been regarded as "normal". It is now widely estimated that a larger percentage of patients with primary open-angle glaucoma (POAG) are suffering from normal tension glaucoma: probably half of all POAG patients in Europe and the majority of POAG patients in East Asia. Among Americans of Japanese descent, for instance, the prevalence of NTG is