Diagnosis: Corneal Abrasion
The most likely diagnosis for a patient with a wood stick injury to the eye is corneal abrasion, which results from mechanical trauma scratching or abrading the corneal epithelium. 1, 2
Why Corneal Abrasion is the Primary Diagnosis
A wood stick represents a low-to-moderate energy mechanism that typically causes superficial corneal epithelial injury rather than deeper penetration or isolated subconjunctival hemorrhage. 1 The mechanism of injury—direct contact with an organic foreign body—classically produces corneal abrasion through mechanical disruption of the protective corneal epithelium. 2, 3
Key Clinical Features Supporting This Diagnosis
- Foreign body sensation is the hallmark symptom of corneal abrasion, which this patient would experience after the wood stick injury 3, 4
- Pain, tearing, and photophobia are expected symptoms that distinguish corneal abrasion from painless subconjunctival hemorrhage 2, 3
- Symptoms worsen with blinking as the eyelid rubs against the abraded corneal surface 3
- Gritty sensation is characteristic of epithelial disruption 3
Why Not the Other Options
Corneal Ulcer (Less Likely Initially)
Corneal ulcer represents a complication or progression of untreated corneal abrasion, not the immediate diagnosis. 2, 4 While organic material like wood carries risk of bacterial contamination (including Bacillus species), 5 ulceration with infiltrate develops over hours to days after the initial injury, not immediately. 1 The patient would present first with abrasion symptoms before progression to ulcer if infection develops. 2
Subconjunctival Hemorrhage (Unlikely)
Subconjunctival hemorrhage is painless and would not explain the "other symptoms" this patient is experiencing. 6 A wood stick injury causing only subconjunctival hemorrhage without corneal involvement would produce visible blood under the conjunctiva but no foreign body sensation, pain, or photophobia—symptoms implied by the clinical scenario. 6
Critical Management Considerations
This patient requires immediate evaluation for penetrating eye injury, embedded foreign body, and corneal ulcer before treating as simple abrasion. 1, 2
Red Flags Requiring Emergent Ophthalmology Referral
- High-velocity mechanism or sharp object penetration (wood sticks can splinter and penetrate) 1
- Irregular pupil after trauma suggests globe penetration 1
- Eye bleeding after trauma beyond simple subconjunctival hemorrhage 1
- Loss of vision indicates serious injury 1
- Persistent foreign body sensation may indicate embedded wood fragment 1
Diagnostic Confirmation
Fluorescein staining under cobalt-blue light will reveal the epithelial defect appearing green, confirming corneal abrasion. 3, 4 Carefully examine for retained wood fragments on the cornea or under the eyelids, as organic foreign bodies significantly increase infection risk. 1, 2
Treatment Algorithm for Confirmed Simple Abrasion
If penetrating injury and embedded foreign body are excluded:
- Topical antibiotics are mandatory due to organic material exposure and contamination risk 2, 4
- Antipseudomonal coverage is NOT needed unless contact lens-related 4
- Topical NSAIDs or oral analgesics for pain control 2, 4
- Do NOT patch the eye—patching delays healing and provides no benefit 3, 4
- Avoid topical cycloplegics for uncomplicated abrasions 4
Follow-Up Requirements
All patients with organic material injuries require 24-hour follow-up to assess for infection development, regardless of abrasion size. 2, 4 Unlike simple traumatic abrasions from clean mechanisms, wood stick injuries carry higher risk of bacterial keratitis and progression to corneal ulcer. 2, 5
Common Pitfall to Avoid
Never assume a wood stick injury is "just an abrasion" without ruling out penetrating injury and retained foreign body. 1, 2 Organic material can introduce virulent organisms like Bacillus species that rapidly progress to sight-threatening ulceration. 5 The American Heart Association guidelines emphasize that high-velocity injuries and sharp objects require immediate medical attention due to potential globe penetration. 1