Best approaches to physical diagnosis of acute red eye
What signs or symptoms are indicative of serious eye disease in patients with red eye or a bacterial cause in patients with presumed conjunctivitis?
Eliciting photophobia via pupillary constriction and the presence of anisocoria (>1 mm) in patients with an acute red eye are the best predictors of serious eye disease (eg, uveitis,
keratitis, corneal abrasion, or 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. (LOE = 2a-)
Narayana S, McGee S. Bedside diagnosis of the ‘red eye’: A systematic review. Am J Med 2015;128(11):1220-1224.