Open angle glaucoma is a disease that causes damage to the optic nerve, the cable of nerve fibers inside the eye that carry visual information to the brain. This is the most common form of glaucoma and a leading cause of blindness in the U.S.. Open, as opposed to narrow or angle closure, refers to the space between the iris (the colored part of the eye) and the cornea (the transparent surface of the eye) where the drainage channel is clearly visible on examination.
The diagnosis of open angle glaucoma is made when there is optic nerve damage with corresponding visual field defect. Most common form of open angle glaucoma is primary open angle glaucoma where the cause is unknown. Secondary open angle glaucomas are glaucomas where pigment, inflammatory cells, blood, or other substances, reduces the outflow of the fluid causing elevated eye pressures. Examples of secondary glaucoma include pigmentary glaucoma and pseudoexfoliation glaucoma. Glaucomatous damage can occur at either high (> 21 mmHg) or normal eye pressure (< 21 mmHg). Glaucoma tends to cause peripheral visual field defect which progresses to affect more central vision as the disease advances. However, damage occurring at normal eye pressure may be associated with insufficient blood flow to the optic nerve and may cause more central rather than peripheral visual field defect.
What are the symptoms of open angle glaucoma?
In most cases, a person with open angle glaucoma does not experience any discomfort and is unaware of any change in vision. Late in the disease, however, extensive loss of peripheral and central vision loss will cause “tunnel vision” and blind spots.
How can I care for my open angle glaucoma?
The treatment for glaucoma is to lower the eye pressure. Initially, open angle glaucoma is typically treated with eye drops which work by either reducing fluid production or increasing fluid outflow. These eye drops are often taken for a lifetime. In cases where eye drops are not tolerated or ineffective, laser treatment (either selective laser trabeculoplasty or argon laser trabeculoplasty) or incisional surgery (trabeculectomy or glaucoma drainage device) is recommended to reduce the pressure in the eye. The treatment goal is to lower the eye pressure sufficiently to prevent or minimize further optic nerve damage.
Damage caused by glaucoma is irreversible. The best way to care of open angle glaucoma is to use the eye drops as prescribed and to keep scheduled follow up appointments.