As the optic nerve deteriorates, blind spots develop, and they can progressively enlarge. If left untreated, glaucoma can also destroy central vision and may progress to total blindness. Acute, or closed-angle , glaucoma accounts for about 10 percent of glaucoma cases in the United States. It primarily occurs in elderly people who are farsighted, and often runs in families. In closed-angle glaucoma, the normal drainage passage between the iris and cornea is narrowed and then blocked.
Laser treatment can cure closed-angle glaucoma which, if untreated, can cause blindness.
Chronic, or open-angle , glaucoma is more common, accounting for approximately 90 percent of glaucoma cases. Because there are no early warning signs, regular eye checkups are important to detect the increased pressure in the eye. In open-angle glaucoma, the drainage passage appears open and not blocked. However, tissue changes in and along the drainage passage prevent aqueous fluid from draining properly.