How should redness in the eye be evaluated and treated?

Evaluation and Management of Eye Redness

Eye redness requires immediate risk stratification using the RAPID acronym (Redness, Acuity loss, Pain, Intolerance to light, Damaged cornea) to identify patients needing emergency ophthalmology referral within 24 hours versus those manageable in primary care. 1

Immediate Red Flag Assessment

Perform urgent evaluation for these vision-threatening features that mandate emergency ophthalmology referral within 24 hours: 1, 2, 3

• Visual loss or significant blurred vision (suggests corneal damage, uveitis, or sight-threatening pathology) 1
• Moderate to severe eye pain (indicates keratitis, uveitis, acute angle-closure glaucoma, or corneal ulceration) 1, 4
• Photophobia with redness (signals corneal or intraocular inflammation beyond simple conjunctivitis) 1, 4
• Corneal involvement identified by fluorescein staining showing epithelial defects or visible corneal opacity/haze 1
• Severe purulent discharge (concerning for gonococcal conjunctivitis requiring systemic antibiotics) 1
• Mid-dilated poorly reactive pupil (suggests acute angle-closure glaucoma or uveitis) 3

Critical caveat: Unilateral redness should prompt consideration of causes other than typical conjunctivitis, as bilateral presentation is more common in benign conditions. 5, 6

Initial Clinical Assessment

Essential History Elements

Document these specific details to guide diagnosis: 2, 6

• Onset and duration of symptoms with diurnal variation 2
• Associated symptoms: discharge character (watery, mucoid, purulent), itching, foreign body sensation, halos around lights 2
• Exacerbating factors: contact lens wear, computer use, environmental exposures 2
• Medication history: topical/systemic medications, particularly dupilumab for atopic dermatitis 2, 5
• Systemic conditions: atopic dermatitis, autoimmune disorders, recent viral illness 2
• History of ocular trauma, surgery, or herpes simplex virus eye disease 1, 6

Physical Examination Components

Perform these specific assessments: 2, 3

• Visual acuity testing in each eye separately (best-corrected) 2
• Pupil examination for size, shape, symmetry, reactivity, and relative afferent pupillary defect 2, 3
• External examination: eyelid assessment for swelling/pain, conjunctival injection pattern, discharge character 2
• Corneal assessment: clarity, luster, and specular reflex (loss of natural transparency is a red flag) 2, 7
• Intraocular pressure measurement if equipment available (elevated IOP suggests acute angle-closure glaucoma) 2

Management Algorithm Based on Severity

Conditions Requiring Emergency Referral (Within 24 Hours)

Refer immediately for: 1, 3

• Preseptal/orbital cellulitis: eyelid swelling with pain, restricted eye movement, proptosis 1, 3
• Infectious keratitis: severe pain, photophobia, blurred vision 1, 3
• Anterior uveitis/iritis: redness, blurred vision, photophobia requiring slit-lamp confirmation 3
• Immunocompromised patients with any red eye (risk of atypical/severe infections) 1
• History of HSV eye disease (increased risk of serious complications) 1
• Conjunctival scarring (suggests severe/chronic disease) 1

Conditions Requiring Urgent Referral (Within 4 Weeks)

Refer within 4 weeks for: 1

• Lack of response to therapy after 3-4 days of appropriate treatment 1
• Recurrent episodes suggesting underlying chronic condition 1
• Severe dry eye unresponsive to treatment when systemic disease suspected 1
• Mild-to-moderate symptoms in adults failing initial treatment with lubricants and lid hygiene 1, 5

Conditions Safe for Primary Care Management

Manage without immediate referral: 1, 6

• Mild bacterial conjunctivitis: Can resolve spontaneously; if treating, use broad-spectrum topical antibiotics and reassess in 3-4 days 1, 6
• Viral conjunctivitis without red flags: Supportive care with preservative-free artificial tears and cold compresses 1, 6
• Allergic conjunctivitis: Topical antihistamines (e.g., olopatadine twice daily) and mast cell stabilizers, cold compresses 1, 5, 8
• Mild blepharitis: Lid hygiene with warm compresses and gentle cleaning of lid margins 1, 3
• Mild dry eye: Preservative-free lubricants 2-4 times daily 1, 5

Treatment Ladder for Primary Care Management

For mild-to-moderate bilateral redness without red flags: 5

Mild severity: Preservative-free lubricants 2-4 times daily 5

Moderate severity: Preservative-free lubricants 2-4 times daily PLUS olopatadine twice daily 5

Severe symptoms: Commence treatment but refer to ophthalmology for assessment within 4 weeks 5

Age-Specific Considerations

Children and Young People

Children under 7 years: Discuss with ophthalmology before initiating treatment due to visual development plasticity 5, 1

Children 7-17 years: Simple treatment can be initiated, but progression up the treatment ladder requires ophthalmology assessment 5, 1

All pediatric patients: Generally require earlier referral than adults and emergency assessment within 24 hours for severe symptoms 1

Special Populations

Patients on dupilumab for atopic dermatitis: 5

• Bilateral redness is typical for dupilumab-related ocular surface disorders (DROSD) 5
• Severe symptoms require emergency referral within 24 hours 5
• Mild-to-moderate symptoms: Start preservative-free lubricants; if requiring tacrolimus ointment to lid margins, refer within 4 weeks 5

Critical Management Pitfalls to Avoid

Never initiate topical corticosteroids before ophthalmology evaluation if red flags are present - steroids worsen infectious keratitis, prolong adenoviral infections, and mask HSV infections. 1, 3, 9

Do not prescribe local anesthetics for red eye management in primary care. 9

Do not delay referral when fluorescein staining or assessment of corneal transparency is needed - these diagnostic procedures belong in ophthalmology. 9

Consider child abuse in cases of sexually transmitted conjunctivitis in children and report accordingly. 1