Which type of glaucoma constitutes a medical emergency?

Closed angle glaucoma represents a medical emergency due to its rapid onset and potential for significant vision loss if not treated promptly. In this condition, the drainage angle between the iris and cornea becomes obstructed, leading to a sudden increase in intraocular pressure. Patients often present with severe eye pain, headache, nausea, vomiting, and blurred vision. They may also exhibit symptoms such as haloes around lights and significant redness of the eye.

The acute nature of closed angle glaucoma requires immediate intervention, such as medications to lower intraocular pressure and, in many cases, surgical procedures to correct the angle closure. If left untreated, this condition can lead to permanent vision loss within hours to days, making it critical to recognize and respond to it as a medical emergency.

Open angle glaucoma and normal tension glaucoma are typically chronic conditions that progress slowly and do not usually present with the acute symptoms associated with closed angle glaucoma. Acute glaucoma is a term that can sometimes be used interchangeably with closed angle glaucoma, but in strict definitions, the latter is considered the medical emergency due to its immediate risks to vision.