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

Acute angle-closure glaucoma is characterized by a sudden increase in intraocular pressure (IOP) due to a blockage of the drainage angle in the eye. This condition occurs when the peripheral iris is pushed or pulled against the trabecular meshwork, preventing aqueous humor from draining out of the eye.

The sudden rise in IOP can lead to rapid onset of symptoms, including severe eye pain, headache, blurred vision, and nausea. Patients may also notice symptoms such as halo rings around lights due to corneal edema. This condition is considered a medical emergency and requires immediate treatment to lower the IOP and prevent optic nerve damage.

Understanding this type of glaucoma is critical because its rapid progression and acute presentation contrast significantly with other types of glaucoma, such as open-angle glaucoma, which typically develops slowly and is asymptomatic in the early stages. Normal-tension glaucoma presents with optic nerve damage despite normal IOP levels, and pigmentary glaucoma involves dispersion of pigment granules in the trabecular meshwork but does not usually present acutely.