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A Systematic Approach to a Red and Painful Eye

Fadial, Tom MD

doi: 10.1097/
    eye care, episcleritis, eye disease:
    Algorithm for Evaluating a Red and Painful Eye

    A 60-year-old woman with rheumatoid arthritis presented with unilateral eye pain and redness without vision changes. A physical examination demonstrated radially oriented, engorged episcleral vessels and normal visual acuity, and she was diagnosed with episcleritis and discharged with follow-up.

    A red or painful eye is a common presentation in the emergency department, and the rapid identification and management of potentially sight-threatening causes is critical.

    The diagnostic approach to the red or painful eye begins with identifying a history of caustic exposure where immediate and copious irrigation (even before detailed examination) may limit further injury. Alkaline agents induce more severe liquefactive necrosis, leading to keratoconjunctivitis, while acidic agents are generally less destructive. Management is identical for both: irrigation with lactated Ringer's solution through a Morgan lens applied to a topically anesthetized eye for five to 10 minutes, repeated until the pH of the eye is neutral. (Emerg Med Pract. 2015;17[11]:1.)

    Ocular or facial trauma presents a spectrum of differential diagnoses. Suspicion for globe rupture is increased by a mechanism such as a high-velocity projectile or high-impact blunt facial trauma. Characteristic examination findings include obvious globe deformity, an irregularly-shaped pupil, extrusion of the vitreous, markedly decreased visual acuity, or parting of fluorescein (Seidel sign).

    Further manipulation is unadvisable if globe rupture is suspected, and the affected eye should be shielded. Measures should be taken to avoid increases in intraocular pressure, including elevating the head of the patient's bed, antiemetics (to prevent intraocular hypertension with vomiting), and avoiding medications potentially implicated in intraocular hypertension (ketamine, succinylcholine). Tetanus and antimicrobial prophylaxis should be provided while awaiting emergent ophthalmology consultation. (Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier. 2018; Emerg Med Clin North Am. 2013;31[2]:399.)

    Retrobulbar hematoma also warrants rapid identification and possible intervention; it is identified by proptosis, eye pain, decreased visual acuity, and elevated intraocular pressure. Pressures exceeding 40 mm Hg require lateral cantholysis in conjunction with medical management to prevent optic nerve ischemia and preserve vision. (Emerg Med Clin North Am. 2008;26[1]:17; J Emerg Med. 2015;48[3]:325.)

    Diagnostic Approach

    The evaluation of a nontraumatic red or painful eye follows a systematic and anatomically-based approach, starting with external components and moving inward:


    The examination begins with assessing function (visual acuity) and inspecting and palpating the periorbital region. Periorbital edema, erythema, and tenderness to palpation in systemic illness (fever) are is concerning for orbital cellulitis. A retrobulbar abscess may be present when associated with elevated intraocular pressure or proptosis.

    Both warrant admission and parenteral antibiotics, and the latter may require operative management such as aspiration or cantholysis. Less severe features without impact on visual acuity are suggestive of a periorbital cellulitis that may be treated as an outpatient with close follow-up. (Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier. 2018; The Patient History: Evidence-Based Approach. 2nd ed. New York: McGraw Hill Professional; 2012.)

    Lids and Lashes

    Several nonemergent processes may affect the lids and lashes, including blepharitis (inflammation of the eyelid margin), chalazion (inflammation of the Meibomian glands), hordeolum (eyelash follicle abscess), or dacryocystitis (infection of the lacrimal sac). (Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier. 2018; The Red Eye, The Swollen Eye, and Acute Vision Loss. Emergency Medicine Practice + EM Practice Guidelines Update. 2002;; N Engl J Med. 2000;343[5]:345.)

    Conjunctiva and Sclera

    Proceeding from superficial to deeper structures, we encounter the epithelial layer (including palpebral and bulbar components) covering the sclera, which is subject to allergic or infectious inflammation. Conjunctivitis is characterized by engorged superficial conjunctival blood vessels, potentially associated with conjunctival edema (chemosis) or discharge. Most conjunctivitis is self-limited and not sight-threatening, and treatment aimed at symptomatic relief through topical antibiotics has few adverse effects and may be prescribed if a diagnosis of bacterial conjunctivitis is unclear. (Emerg Med Clin North Am. 2008;26[1]:3.)

    A deeper inflammatory process is implicated when associated with pain. Scleritis is a frequently immune-mediated inflammatory process (though infection, malignancy, and medications have been implicated) associated with pain, photophobia, globe tenderness, and engorged scleral blood vessels. Management in the emergency department is trivial (systemic NSAIDs), but ophthalmology should be consulted because of the risk of vision-compromising complications and the intimation of an underlying systemic disorder. (Emerg Med Clin North Am. 2008;26[1]:3; Int Ophthalmol Clin. 2005;45[2]:191.)

    Episcleritis is similarly immune-mediated, though generally self-limiting. The diagnosis is made by identification of characteristic radially-oriented, engorged episcleral vessels. The application of a topical vasoconstrictor (phenylephrine 2.5%) will blanch vessels in the conjunctival or superficial episcleral plexuses, sparing scleral vessels, when the diagnosis of scleritis versus episcleritis or conjunctivitis is in question. (Int Ophthalmol Clin. 2005;45[2]:191; JAAPA. 2006;19[3]:24.)


    Keratitis can be caused by infection, ultraviolet light exposure, or contact lens use. Patients may have photophobia and a foreign body sensation. Gross inspection or slit lamp examination will show epithelial erosions that stain with fluorescein or the characteristic dendritic pattern accompanying herpes simplex virus infection. Management includes ophthalmology consultation, topical antibiotics if a bacterial process is suggested, and close follow-up. (The Red Eye, The Swollen Eye, and Acute Vision Loss. Emergency Medicine Practice + EM Practice Guidelines Update. 2002;; N Engl J Med. 2000;343[5]:345; Emerg Med Clin North Am. 2008;26[1]:3; Evaluation of the Red Eye. UpToDate. Feb. 24, 2016.)

    Anterior Chamber

    Angle-closure glaucoma is a critical process occurring in the anterior chamber. The patient commonly presents with severe pain, circumcorneal injection, and a pupil fixed at mid-dilation. Diagnosis is confirmed by a measurement greater than 20 mm Hg of intraocular pressure. Reduction of intraocular pressure with topical and systemic agents should begin immediately while awaiting emergent ophthalmology consultation. (Ophthalmology. 2016;123[1]:P1.)

    The slit lamp microscope facilitates examination of the anterior chamber. The presence of cells (floating white and red blood cells or layering hypopyon or hyphema) and flare (protein) suggest inflammation in the anterior segment caused by a systemic inflammatory process, infection, or trauma, and warrants close ophthalmologic follow-up. (Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier. 2018; The Red Eye, The Swollen Eye, and Acute Vision Loss. Emergency Medicine Practice + EM Practice Guidelines Update. 2002;; Emerg Med Clin North Am. 2008;26[1]:3.)


    An ocular examination mimicking orbital cellulitis with evidence of anterior chamber involvement, particularly in a patient with a history of recent ocular surgery or trauma, suggests endophthalmitis. Management requires ophthalmology consultation and admission for parenteral antibiotics. (Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier. 2018.)

    Additional Diagnostic Modalities

    Advanced imaging may be useful in diagnosing traumatic and nontraumatic orbital pathology. Multidetector computed tomography is readily available and rapidly performed in the emergency department, and it can aid in diagnosing critical infectious processes, including extension beyond the orbital septum in orbital cellulitis, scleral thickening in endophthalmitis, and characterization of hematoma or abscess in the retrobulbar space. The addition of intravenous contrast media can identify critical vascular processes such as cavernous sinus thrombosis. (Radiographics. 2008;28[6]:1741;; Semin Ultrasound CT MR. 2011;32[1]:38.)

    CT can also assist in evaluating globe integrity, lens position, vitreous and retinal detachment, and foreign bodies. (Semin Ultrasound CT MR. 2011;32[1]:51.) Imaging cannot be relied upon exclusively to exclude pathology, and the patient's presentation and clinician's examination should determine the need for consultation and evaluation. CT failed to diagnose open globe injury in a third of patients in a study of 59 patients with severe ocular trauma and diagnostic uncertainty about the presence of globe rupture (with surgical scleral inspection as a reference standard). (Rofo. 2010;182[2]:151.)

    Another retrospective analysis of 48 eyes that had sustained trauma revealed sensitivity ranging from 56% to 68% for CT identification of open globe injury. (Ophthalmology. 2007;114[8]:1448.)

    Computed tomography, in addition to potential diagnostic inaccuracy, exposes patients to the risks of ionizing radiation and the possibility of contrast-induced nephropathy. (Curr Opin Ophthalmol. 2014;25[5]:432.) Ultrasound is becoming increasingly accessible and familiar to emergency physicians, and it has the benefit of being relatively noninvasive while also facilitating ocular examination in patients with significant periorbital swelling that limits a patient opening his eye.

    Ocular ultrasound may aid in diagnosing a wide variety of ocular pathology including vitreous hemorrhage, retinal detachment, central retinal arterial/venous occlusions, foreign body identification, lens dislocation, and retrobulbar hematoma. Ultrasound interpretation agreed with criterion standard (orbital computed tomography or ophthalmology evaluation) in 98 percent of cases in a study of 61 patients presenting with trauma or acute vision changes. (Acad Emerg Med. 2002;9[8]:791.)

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    Dr. Fadialis an assistant professor of emergency medicine at McGovern Medical School in Houston. As the educational technology and innovation officer there, he develops unique educational tools, including algorithms, that can be found at His other medical education projects can be found at Follow him on Twitter@thame.

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