Bedside Diagnosis of the 'Red Eye': A Systematic Review.

BACKGROUND: In patients with red eye, traditional teachings suggest that photophobia, visual blurring, and eye pain indicate serious eye disease; in patients with presumed conjunctivitis, the finding of purulent drainage traditionally indicates a bacterial cause. The accuracy of these teachings is unknown.

METHODS: A MEDLINE search was performed to retrieve articles published between 1966 and April 2014 relevant to the bedside diagnosis of serious eye disease and bacterial conjunctivitis.

RESULTS: In patients with red eye, the most useful findings indicating serious eye disease are anisocoria (with the smaller pupil in the red eye and difference between pupil diameters >1 mm; likelihood ratio [LR], 6.5; 95% confidence interval [CI], 2.6-16.3) and photophobia, elicited by direct illumination (LR, 8.3; 95% CI, 2.7-25.9), indirect illumination (LR, 28.8; 95% CI, 1.8-459), or near synkinesis test ("finger-to-nose convergence test," LR, 21.4; 95% CI, 12-38.2). In patients with presumed conjunctivitis, complete redness of the conjunctival membrane obscuring tarsal vessels (LR, 4.6; 95% CI, 1.2-17.1), observed purulent discharge (LR, 3.9; 95% CI, 1.7-9.1), and matting of both eyes in the morning (LR, 3.6; 95% CI, 1.9-6.5) increase the probability of a bacterial cause; failure to observe a red eye at 20 feet (LR, 0.2; 95% CI, 0-0.8) and absence of morning gluing of either eye (LR, 0.3; 95% CI, 0.1-0.8) decrease the probability of a bacterial cause.

CONCLUSIONS: Several bedside findings accurately distinguish serious from benign eye disease in patients with red eye and, in patients with presumed conjunctivitis, distinguish bacterial from viral or allergic causes.