A 44-year-old woman presents with acute left eye pain and minimal reactive dilated pupil. What is the most likely condition?

The scenario described points toward acute angle closure glaucoma as the most likely condition. This condition is often characterized by sudden onset eye pain, which can be severe, and is commonly associated with a dilated pupil that has minimal reactivity to light. The minimal reactivity indicates that the pupil is likely not responding properly due to the elevated intraocular pressure caused by the angle closure.

In acute angle closure glaucoma, the drainage angle of the eye becomes obstructed, leading to a rapid increase in intraocular pressure. This can also cause additional symptoms such as headache, blurred vision, and nausea. The acute nature of the symptoms and the specific manifestation of a painful eye and a poorly reactive pupil strongly suggest this diagnosis over the other options.

Central retinal artery occlusion, while it can present with sudden vision changes, would more likely feature a pale retina and a "cherry-red spot" on examination, rather than associated eye pain and pupil reactivity issues. Optic neuritis is usually accompanied by other symptoms, such as visual loss and possible color vision changes, but typically does not present with an acute painful eye and a dilated pupil. Vitreous hemorrhage may lead to sudden vision loss but is less associated with eye pain and a non-reactive pupil.