Are there different forms of glaucoma?
There are two main forms of glaucoma: open-angle (the most common form, affecting approximately 70-95% of individuals); and angle-closure. There are also several other forms of glaucoma, including normal-tension, congenital, juvenile, and secondary.
Open-angle glaucoma, the most common form of the disease, is progressive and characterized by optic nerve damage. The most significant risk factor for the development and advancement of this form is high eye pressure. Initially, there are usually no symptoms, but as eye pressure gradually builds, at some point the optic nerve is impaired and peripheral vision is lost. Without treatment, an individual can become totally blind.
Angle-closure glaucoma may be acute or chronic. In acute angle-closure glaucoma, the normal flow of eye fluid (aqueous humor) between the iris and the lens is suddenly blocked. Symptoms may include severe pain, nausea, vomiting, blurred vision, and seeing a rainbow halo around lights. Acute angle-closure glaucoma is a medical emergency and must be treated immediately, or blindness could result in one or two days. Chronic angle-closure glaucoma progresses more slowly and can damage the eye without symptoms, similar to open-angle glaucoma.
Normal-tension glaucoma occurs when eye pressure is normal, yet the optic nerve is damaged and peripheral vision is lost. Lowering eye pressure through medication sometimes slows the progress of the disease, but this type of glaucoma may worsen despite low pressure. The treatment is generally the same as for open-angle glaucoma.
Congenital glaucoma affects infants born with defects that prevent the normal drainage of fluid from the eye.
Juvenile glaucoma is open-angle glaucoma that affects children, adolescents and young adults.
Secondary glaucoma can be open-angle or closed-angle and is the result of some other medical condition in the eye or the body.