A 45-year-old African-American woman presents to the emergency department with the complaint that "my eye hurts, and it's far too bright in here." She has one hand cupped over her left eye. She denies any history of trauma or the presence of a foreign body sensation in either eye. Physical examination reveals significant redness at the junction between the cornea and sclera of the left eye. The left pupil is irregular and constricted and she recoils when the penlight is shined in either eye. Visual acuity is reduced in the left eye. Slit lamp examination shows the presence of leukocytes in the anterior segment of this eye. What is the cause of this woman's symptoms?
Anterior uveitis (iritis) is characterized by pain, redness, variable visual loss, and a constricted and irregular pupil. To properly distinguish iritis from other causes of a red eye, it is important to visualize the anterior segment of the eye with slit lamp examination. If leukocytes are seen in the anterior segment, which contains the aqueous humor found between the cornea and the lens, then the diagnosis of iritis (Choice D) is confirmed. A hazy "flare," which is indicative of protein accumulation secondary to a damaged blood-aqueous barrier, may also be seen. Treatment for iritis depends on the etiology of the condition, and typically includes antimicrobial therapy for viral or bacterial causes and topical corticosteroids for noninfectious causes.
Acute closed angle glaucoma (Choice A) may cause symptoms similar to those found in iritis, but is confirmed by documenting elevated intraocular pressure.
Conjunctivitis (Choice B) is a diagnosis of exclusion, and is made in a patient with red eye and discharge only if vision is normal and there is no evidence of glaucoma, iritis, or keratitis.
Infectious keratitis (Choice C) is characterized by severe photophobia and difficulty in keeping the affected eye open. Penlight examination reveals a corneal opacity or infiltrate.
A red eye can result from the presence of a foreign body or a corneal abrasion resulting from trauma (Choice E), but such information is normally provided in the patient's history. Penlight examination should provide confirmation.
Educational Objective:
Anterior uveitis (iritis) is characterized by pain, redness, variable visual loss, and a constricted and irregular pupil. Visualization of leukocytes in the anterior segment confirms the diagnosis.