Red and Painful Eye

A particular challenge in the emergency department is evaluating the patient who presents with a red and painful eye. This assessment requires detailed understanding of ocular anatomy, the components and implementation of a complete eye examination, and the ability to discern which critical diagnoses require immediate intervention to prevent long-term vision loss. Pivotal findings that are indicative of a more serious diagnosis include severe pain, vision changes, proptosis, reduced light reflex, corneal defect or opacity, history of contact lens use, immunocompromise, neonate, or worsening signs after treatment. Pivotal findings can be found during complete eye examination, including ancillary testing such as tonometry, funduscopic exam, and slit-lamp exam. The critical, emergent, and urgent diagnoses to consider are outlined in a diagnostic algorithm, anchored by time-sensitive conditions of caustic injury needing immediate irrigation, or orbital compartment syndrome requiring rapid orbital decompression. In order to approach the undifferentiated patient with ocular pain or redness, empiric management is detailed to include urgent, but nonemergent, diagnoses that are most commonly seen, including conjunctivitis, corneal abrasion, subconjunctival hemorrhage, and hordeolum.