This is NOT Viral Conjunctivitis—This is Viral Keratitis
The presence of punctate fluorescein uptake on the cornea indicates corneal epithelial involvement (keratitis), not simple conjunctivitis. This is a critical distinction that changes both diagnosis and management, as keratitis carries significant risk for vision loss while conjunctivitis does not 1.
Why This Matters for Vision
The corneal involvement with fluorescein staining indicates viral keratitis, which can lead to:
- Corneal scarring and permanent vision loss
- Stromal infiltration and neovascularization
- Corneal perforation in severe cases
- Chronic complications including dry eye and recurrent disease 1, 2
Conjunctivitis, by contrast, affects only the conjunctiva and rarely threatens vision unless complicated by keratitis 1.
Distinguishing Features from the Guidelines
Viral conjunctivitis (adenoviral) presents with 1:
- Watery discharge (not absent discharge)
- Follicular reaction on inferior tarsal conjunctiva
- Bulbar conjunctival injection
- Usually bilateral or sequentially bilateral
- No corneal epithelial defects initially (though keratitis can develop as a complication)
Viral keratitis presents with 1:
- Punctate epithelial keratitis with fluorescein uptake (exactly what this patient has)
- Unilateral presentation (as in this case)
- Eye pain (present here)
- Minimal to no discharge (matches this presentation)
Most Likely Viral Etiologies
Given unilateral presentation, pain, and punctate keratitis without discharge:
Herpes Simplex Virus (HSV) is most likely 1:
- Usually unilateral
- Punctate or dendritic epithelial keratitis
- Watery discharge or minimal discharge
- Can present without classic dendritic pattern early
- Risk of severe complications: stromal keratitis, scarring, perforation, uveitis
Varicella Zoster Virus (VZV) is also possible 1:
- Typically punctate keratitis in primary disease
- Pseudodendritic pattern in recurrent disease
- Usually unilateral with severe pain
- Look for vesicular dermatomal rash on eyelids
Adenoviral keratitis less likely here 1:
- Would expect more discharge and follicular conjunctivitis
- Usually bilateral or becomes bilateral
Critical Next Steps
Immediate actions:
- Examine eyelids carefully for vesicular lesions (HSV/VZV) 1
- Assess corneal sensation (reduced in HSV keratitis) 2
- Look for dendritic or geographic patterns with fluorescein—may be subtle early 1
- Check for anterior chamber reaction (cells/flare indicating uveitis) 1
Do NOT:
- Use topical corticosteroids without antiviral coverage—this can worsen HSV keratitis catastrophically 2
- Use topical anesthetics beyond examination—delays healing 2
- Dismiss as simple conjunctivitis—the corneal involvement demands urgent ophthalmology evaluation
Management Algorithm
For presumed HSV keratitis (most common cause of unilateral punctate keratitis):
- Start topical antiviral immediately (ganciclovir gel or trifluridine drops) 3
- Consider oral acyclovir 400mg 5x daily for severe cases 3
- Ophthalmology referral within 24 hours 4
- Close follow-up to monitor for progression 2
Red flags requiring same-day ophthalmology consultation 4:
- Severe pain (present in this case)
- Any vision decrease
- Central corneal involvement
- Stromal infiltration
- Anterior chamber reaction
Common Pitfall
The most dangerous error is misdiagnosing viral keratitis as viral conjunctivitis and either providing no treatment or, worse, prescribing topical steroids alone. The corneal epithelial defect visible with fluorescein is the key distinguishing feature that elevates this from a self-limited conjunctivitis to a potentially vision-threatening keratitis requiring antiviral therapy and specialist evaluation 1, 2, 4.