Appropriate History and Workup for a Patient with Red Eye
A thorough history and focused examination are essential for diagnosing the cause of red eye, with particular attention to symptoms, onset pattern, associated findings, and risk factors to determine urgency and appropriate management.
Key History Elements
- Duration of symptoms, character of discharge, unilateral vs. bilateral presentation, and associated symptoms 1, 2
- Pain level (severe pain suggests serious conditions requiring urgent care) 1, 3
- Visual changes (decreased vision is a red flag requiring immediate referral) 1, 2
- Photophobia (sensitivity to light suggests corneal involvement or inflammation) 1, 3
- Discharge characteristics (purulent suggests bacterial, watery suggests viral or allergic) 1, 2
- Contact lens history (wearing schedule, hygiene, overnight wear) 1
- Recent trauma, surgery, or foreign body sensation 1, 4
- Associated systemic symptoms (upper respiratory infection, skin conditions) 1, 2
- Medical history (hypertension, diabetes, autoimmune conditions) 1
- Current medications and allergies 1
Physical Examination Components
- Visual acuity measurement (decreased vision requires urgent evaluation) 1
- External examination of eyelids, periorbital area, and regional lymph nodes 1
- Pupillary assessment (relative afferent pupillary defect suggests ischemic conditions) 1
- Slit-lamp biomicroscopy to evaluate:
- Intraocular pressure measurement (elevated in acute glaucoma) 1
- Funduscopic examination when indicated 1
Red Flag Symptoms Requiring Immediate Referral
- Moderate to severe eye pain 2, 3
- Decreased vision 1, 6
- Photophobia 1, 3
- Corneal opacity or epithelial defect 1
- History of trauma or chemical exposure 6, 4
- Contact lens wear with pain and redness 1, 4
- Severe purulent discharge 1, 2
- Lack of response to initial therapy 7, 4
Diagnostic Tests to Consider
- Fluorescein staining to identify corneal epithelial defects 5
- Eversion of upper eyelid to check for foreign bodies or papillary reaction 1, 2
- Cultures in cases of severe or unresponsive purulent discharge 1
- Preauricular lymph node palpation (enlargement suggests viral or chlamydial infection) 1, 2
Common Diagnostic Patterns
Viral Conjunctivitis
- Often unilateral initially, becoming bilateral
- Watery discharge, follicular reaction
- Preauricular lymphadenopathy
- Often associated with upper respiratory infection 1, 2
Bacterial Conjunctivitis
- Unilateral or bilateral
- Purulent or mucopurulent discharge
- Papillary rather than follicular reaction
- Less commonly associated with preauricular lymphadenopathy 1, 2
Allergic Conjunctivitis
- Bilateral, intense itching
- Watery discharge, chemosis
- Papillary reaction
- History of atopy or seasonal pattern 1
Acute Angle-Closure Glaucoma
- Severe pain, decreased vision
- Mid-dilated pupil, corneal edema
- Elevated intraocular pressure
- Nausea/vomiting may be present 6, 4
Keratitis/Corneal Ulcer
- Pain, photophobia, decreased vision
- Corneal infiltrate or epithelial defect
- History of contact lens wear or trauma
- Anterior chamber reaction may be present 1
Anterior Uveitis
- Pain, photophobia, decreased vision
- Circumcorneal injection (limbal flush)
- Cells and flare in anterior chamber
- Miotic or irregular pupil 6, 4
Common Pitfalls to Avoid
- Failing to check visual acuity, which can miss vision-threatening conditions 6, 3
- Indiscriminate use of topical antibiotics for all red eyes 1, 2
- Using corticosteroids without ruling out infectious keratitis 1
- Overlooking dry eye syndrome as a cause of chronic red eye 7, 4
- Failing to recognize the urgency of chemical burns or globe injuries 6, 4
- Not considering systemic conditions that can present with red eye 1, 6
Remember that proper history and examination are crucial for distinguishing between benign conditions that can be managed in primary care and serious conditions requiring urgent ophthalmological referral 8, 6.