Angle-closure glaucoma, a less common form of glaucoma, is the result of a closed or narrow angle formed at the junction of the cornea and iris. This blockage of the drainage canal elevates pressure within the eye, damaging the optic nerve. The onset of angle-closure glaucoma can be either abrupt or slowly progressive.
Risk factors for angle-closure glaucoma include:
- family history
- Asian or Eskimo ancestry
Following are the different sub-types of angle-closure glaucoma:
Acute angle-closure glaucoma occurs from a sudden, complete blockage of the drainage meshwork and an abrupt rise in intraocular pressure. Symptoms of acute angle-closure glaucomamay include severe eye and facial pain, nausea, redness of the eye and blurred vision. Acute angle-closure glaucoma is a medical emergency that can result in vision loss within hours if treatment is not started to lower the intraocular pressure, clear the blockage and restore the flow of fluid within the eye.
Chronic angle-closure glaucoma, where blockage may occur slowly over time as scar tissue forms in areas where the iris is in contact with the drainage channels. Because the rise in eye pressure is gradual, symptoms of ocular redness, pain, nausea, and blurred vision are generally absent, despite marked pressure elevation. Like the more prevalent open-angle glaucoma, chronic angle-closure can cause vision damage without symptoms.
Secondary angle-closure glaucoma, which (like secondary open-angle glaucoma) develops as the result of other medical or ophthalmic conditions, and can occur in one or both eyes. These may include poorly controlled diabetes, traumatic eye injury, certain drugs, advanced cataracts, and uveitis (a serious inflammation of the middle layer of the eye).