Evaluation of the Painful Eye.

Eye pain is a common presentation in outpatient, urgent care, and emergency settings. Causes range from benign to vision-threatening. Family physicians should promptly identify red-flag features that require urgent or emergent ophthalmology referral. A painful eye with vision loss, severe photophobia, proptosis, hyphema, or corneal ulceration is a medical emergency. Patient history should include onset, associated vision changes, contact lens use, trauma, chemical exposure, systemic symptoms, and rheumatologic disease. Physical examination should include evaluation of visual acuity (eg, using a Snellen or Rosenbaum chart), pupillary reactions, and extraocular movements. The eyes should be inspected for redness, discharge, and corneal lesions with fluorescein, if available. Findings of significant photophobia, anisocoria, dendritic corneal lesions, or restricted eye movement should prompt immediate referral. Common emergent causes of eye pain include acute angle-closure glaucoma, orbital cellulitis, infectious keratitis, scleritis, and anterior uveitis. An algorithmic approach that distinguishes urgent vs nonurgent etiologies and ophthalmic vs nonophthalmic causes of eye pain can direct next steps.