Best Approaches to Physical Diagnosis of Acute Red Eye


Am Fam Physician. 2016 Apr 1;93(7):594.

Clinical Question

Which signs or symptoms are indicative of serious eye disease in patients with red eye or a bacterial cause in patients with presumed conjunctivitis?

Bottom Line

Eliciting photophobia via pupillary constriction and the presence of anisocoria (greater than 1 mm) in patients with an acute red eye are the best predictors of serious eye disease (e.g., uveitis, keratitis, corneal abrasion, scleritis) requiring prompt referral. Lack of morning eye matting is a fairly good way to rule out bacterial conjunctivitis, but no sign or symptom in this study consistently identifies a bacterial cause or response to antibiotic treatment. (Level of Evidence = 2a−)


The authors conducted a limited search, using only a single database (PubMed) and selecting only English-language studies that evaluated the diagnostic accuracy of the history and physical examination in adult patients with red eye. They included studies that enrolled patients with presumed conjunctivitis who had bacterial culture or patients with red eye, all of whom eventually underwent slit-lamp examination. Two authors independently extracted the data. They did not evaluate the quality of the research. In five studies of 957 consecutive patients with red eye, the most useful findings that indicated serious eye disease were anisocoria (with the smaller pupil in the red eye and difference between pupil diameters greater than 1 mm; positive likelihood ratio [LR+] = 6.5; 95% confidence interval [CI], 2.6 to 16.3) and photophobia, elicited by direct illumination (LR+ = 8.3; 95% CI, 2.7 to 25.9), indirect illumination (LR+ = 28.8; 95% CI, 1.8 to 459), or finger-to-nose test (LR+ = 21.4; 95% CI, 12 to 38.2). In three studies of 281 patients enrolled consecutively with presumed conjunctivitis, 45% had positive bacterial cultures. No sign or symptom was particularly effective at identifying bacterial conjunctivitis, either alone or in combination. The lack of morning “glue eye” (LR- = 0.3; 95% CI, 0.1 to 0.8) or failure to observe a red eye at 20 feet (LR- = 0.2; 95% CI, 0 to 0.8) may be useful for ruling out a bacterial cause. None of the included studies evaluated the ability of any sign or symptom to predict response to topical antibiotic treatment.

Study design: Systematic review

Funding source: Self-funded or unfunded

Setting: Various (meta-analysis)

Reference: Narayana S, McGee S. Bedside diagnosis of the ‘red eye’: a systematic review. Am J Med. 2015; 128( 11): 1220– 1224.e1.

POEMs (patient-oriented evidence that matters) are provided by EssentialEvidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, please see http://www.essentialevidenceplus.com. Copyright Wiley-Blackwell. Used with permission.

For definitions of levels of evidence used in POEMs, see http://www.essentialevidenceplus.com/product/ebm_loe.cfm?show=oxford.

To subscribe to a free podcast of these and other POEMs that appear in AFP,search in iTunes for “POEM of the Week” or go to http://goo.gl/3niWXb.

This series is coordinated by Sumi Sexton, MD, Associate Deputy Editor.

A collection of POEMs published in AFP is available at https://www.aafp.org/afp/poems.



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