What is the most likely cause of eye pain in a woman with rheumatoid arthritis and a red eye?

In assessing eye pain in a patient with rheumatoid arthritis accompanied by a red eye, acute anterior uveitis stands out as the most probable cause. This condition is characterized by inflammation of the uveal tract, particularly the iris, and is frequently associated with systemic inflammatory diseases like rheumatoid arthritis.

Patients with rheumatoid arthritis have an increased risk of developing ocular complications, including uveitis. Symptoms typically include significant eye pain, photophobia, redness, and blurred vision. The presentation of redness is often localized to the ciliary area, and findings on examination may reveal a reaction in the anterior chamber, such as cells and flare.

While acute glaucoma, conjunctivitis, and scleritis can indeed cause discomfort and redness in the eye, they present with different underlying mechanisms and symptoms. Acute glaucoma often features sudden onset of severe eye pain, headache, nausea, and vomiting, along with a mid-dilated, nonreactive pupil. Conjunctivitis generally presents with eye discharge and less pain. Scleritis is more commonly associated with severe pain that may wake the patient from sleep, but it does not have the same association with rheumatoid arthritis as acute anterior uveitis does.

Thus, the presence of rheumatoid arthritis and the specific symptoms described strongly indicate