Review Question - QID 105035

This patient presents with acute closed angle glaucoma characterized by unilateral vision loss, eye pain and redness, mydriasis, and poor responsiveness to light.

Acute closed angle glaucoma is caused by enlargement or forward movement of the lens against the central iris, leading to obstruction of the normal aqueous flow through the pupil (Illustration A). This causes fluid buildup behind the iris, pushing the peripheral iris against the cornea and impeding flow through the trabecular network. When this occurs acutely, it presents with unilateral severe eye pain and vision loss. It is often accompanied by halos around light, eye hardness, and frontal headaches. The treatment is pilocarpine, an acetylcholine agonist.

Pokhrel and Loftus review the diagnosis and management of ocular emergencies. They state all ocular emergencies, including a penetrating globe injury, retinal detachment, central retinal artery occlusion, acute angle-closure glaucoma, and chemical burns, should be referred immediately to the emergency department or an ophthalmologist. Furthermore, they state that all patients with eye problems should be tested for visual acuity and ocular movements. Confrontation visual field examination, pupillary examination, and direct ophthalmoscopy of both eyes also should be performed.

Sng et al. review the mechanism of acute angle closure glaucoma. They state that more shallow anterior chamber depth was the main anterior segment biometric parameter associated with acute primary angle closure during the attack. Furthermore, they state anatomic changes in the anterior segment explained only about one third of the variance in acute primary angle closure occurrence, and the role of nonanatomic factors require further investigation.

Figure A demonstrates conjunctival injection and mydriasis which is common in acute closed angle glaucoma. Illustration A demonstrates the pathophysiology of acute closed angle glaucoma. Illustration B demonstrates the characteristic opacity seen in cataracts. Illustration C demonstrates retinal whitening with a cherry-red spot as is commonly seen in central retinal artery occlusion. Illustration D demonstrates the "blood and thunder" image that would be seen on funduscopic exam in central retinal vein occlusion.

Incorrect Answers:
Answer 1: Open angle glaucoma is characterized by peripheral, then central PAINLESS vision loss, and is associated with increasing age.
Answer 3: Cataracts are painless opacifications of the lens seen with advanced age. The opacification would be clearly evident on physical exam as seen in Illustration B.
Answer 4: Central retinal artery occlusion (CRAO) is characterized by sudden, painless blindness and a pale retina with a cherry-red macula on funduscopic evaluation as seen in Illustration C.
Answer 5: Central retinal vein occlusion can present similarly to CRAO, but a "blood and thunder" image would be seen on funduscopic exam as shown in Illustration D.