Rationale:

• Snellen acuity can be decreased by punctate keratitis and discharge and debris in tear film.
• Acute viral infection tends to cause hyperemia, follicular response, and watery discharge.
• Preauricular lymphadenopathy is prominent in acute adenoviral conjunctivitis but may also be present in picornaviral conjunctivitis.
• Acute viral infection can cause marked exudative response, which can result in pseudomembranes in upper or lower fornix.
• Bulbar conjunctiva may show petechial or large subconjunctival hemorrhages.
• Corneal infiltrates (subepithelial infiltrates) may develop after the acute phase of the adenoviral disease subsides (day 7 to 10) but are rarely seen in picornaviral conjunctivitis.
• Acute epithelial infiltrates and punctate keratitis in cornea stain green with fluorescein dye.

Evidence:

• Physical exam features associated with viral conjunctivitis are reviewed in an article (1) and in a book chapter about diseases of the outer eye (3).
• Epidemiologic and clinically based studies clearly document clinical features of epidemic keratoconjunctivitis (10; 11).
• Lymphadenopathy is found in approximately 50% of patients (12).
• Acute viral disease is usually bilateral but may be unilateral in up to 20% of cases (1; 13).
• The development of corneal infiltrates is an inflammatory repsonse that may occur in 35% to 50% of patients with epidemic keratoconjunctivitis (12; 13; 14; 15).
• Adenoviral positive cultures may be found in 5% to 10% of patients at 14 days (16).

Comments:

• Studies suggest that it is often difficult to differentiate viral from bacterial or allergic disease by the clinical exam. Clinical accuracy of about 40% to 70% compared to laboratory confirmation has been shown (6; 7; 17; 18; 9).