What type of glaucoma is characterized by a sudden increase in intraocular pressure?

Closed-angle glaucoma, also known as narrow-angle glaucoma, is characterized by a sudden increase in intraocular pressure due to a blockage of the drainage angle formed by the cornea and the iris. This can occur when the iris is pushed or pulled forward, narrowing or closing off the angle and preventing aqueous humor from draining out of the eye.

The sudden elevation in intraocular pressure can lead to severe eye pain, headache, nausea, vomiting, and even vision loss if not treated promptly. This acute condition is often associated with changes in the iris and underlying anatomical features of the eye that predispose individuals to this type of glaucoma.

In contrast, open-angle glaucoma typically develops gradually over time without acute symptoms and involves a slow clogging of the drainage canals, leading to increased pressure. Normal tension glaucoma occurs when optic nerve damage happens despite normal intraocular pressure levels, and secondary glaucoma is caused by other medical conditions or medications that affect eye pressure. Therefore, the hallmark of closed-angle glaucoma is its sudden onset and the dramatic rise in intraocular pressure, making it crucial for prompt diagnosis and intervention.