Answer
B: Scleritis
Educational Objective
Diagnose scleritis in a patient with rheumatoid arthritis.
Critique
The most likely diagnosis in this patient with rheumatoid arthritis (RA) is scleritis. RA is one of the most common diseases associated with scleritis. Typical features include eye pain, pain with gentle palpation of the globe, and photophobia. The deep scleral vessels are involved and may lead to scleromalacia, which is characterized by thinning of the sclera and is seen as a dark area in the white sclera. Scleromalacia may lead to perforation of the sclera, called scleromalacia perforans. Scleritis can be vision-threatening and lead to blindness; it is therefore important to urgently refer the patient to an ophthalmologist for care.
Episcleritis is an abrupt inflammation of the superficial vessels of the episclera, a thin membrane that lies just beneath the conjunctiva. The cause is often unclear; rarely, it is associated with systemic rheumatologic disease. Patients with episcleritis frequently present without pain or decreased visual acuity. On examination, the inflammation appears localized. White sclera can be seen between superficial dilated blood vessels. Episcleritis typically resolves spontaneously. The presence of severe pain, diffuse redness, and decreased visual acuity make episcleritis an unlikely diagnosis.
Subconjunctival hemorrhage is a common disorder and typically benign in origin. It is caused by painless bleeding into the superficial portion of the eye. Examination reveals a blotchy redness (from extravascular blood) that is typically confined to one area of the conjunctiva. Subconjunctival hemorrhage is painless and not associated with loss of vision. Most cases resolve within several weeks without intervention. The patient's findings are not compatible with subconjunctival hemorrhage.
Viral conjunctivitis also causes a red eye. Typically, the underlying vessels are visible, a watery discharge may be seen, and the eyelids are matted in the morning. The eye may feel irritated, but there is no pain or loss of visual acuity. In general, conjunctivitis is a diagnosis of exclusion. The presence of pain and decreased visual acuity exclude viral conjunctivitis in this patient.
Key Point
Rheumatoid arthritis is one of the most common diseases associated with scleritis, which can be vision-threatening and lead to thinning of the sclera and perforation.
Bibliogrpahy
Artifoni M, Rothschild PR, Br茅zin A, Guillevin L, Pu茅chal X. Ocular inflammatory diseases associated with rheumatoid arthritis. Nat Rev Rheumatol. 2014;10:108-16. [PMID: 24323074] doi:10.1038/nrrheum.2013.185