Narrow angle glaucoma, also known as angle closure glaucoma, is a type of glaucoma that occurs when the drainage channels in the eye become blocked or narrow, leading to a sudden increase in intraocular pressure (IOP). The IOP increase can damage the optic nerve and cause vision loss if left untreated. Narrow angle glaucoma is less common than open angle glaucoma, which is the most common type of glaucoma.
The angle of the eye is the area where the cornea (the clear front part of the eye) meets the iris (the colored part of the eye). It is where the aqueous humor (a clear fluid that nourishes the eye) drains out of the eye. In narrow angle glaucoma, the angle is too narrow, which can cause the iris to block the drainage channels, leading to a sudden increase in IOP.
Symptoms of narrow angle glaucoma include sudden eye pain, blurred vision, halos around lights, nausea, and vomiting. These symptoms can come on suddenly and are often severe, and can indicate an acute attack of narrow angle glaucoma, which is a medical emergency. If you experience these symptoms, it's important to seek immediate medical attention to prevent permanent vision loss.
Risk factors for narrow angle glaucoma include age, family history of glaucoma, being farsighted, and certain medical conditions such as diabetes and hyperthyroidism. Women are also more likely to develop narrow angle glaucoma than men.
Diagnosis of narrow angle glaucoma typically involves a comprehensive eye exam, including measuring IOP, examining the angle of the eye using a special lens, and assessing the optic nerve for signs of damage. Additional tests, such as visual field testing and optical coherence tomography (OCT), may also be performed.
Treatment for narrow angle glaucoma involves lowering the IOP to prevent damage to the optic nerve. This can be done with medications that reduce the production of aqueous humor or increase its drainage, or with laser treatment. Laser treatment involves creating a small hole in the iris to improve the flow of aqueous humor and reduce IOP. Surgery may be needed in severe cases of narrow angle glaucoma that do not respond to other treatments.