The main decision in evaluating a patient with a red eye is whether the disorder is likely to recover without sequela or whether there is a potentially serious problem. If the patient has bacterial conjunctivitis, the cornea is clear, and the patient is not significantly uncomfortable, then they should be treated with topical antibiotics. A culture is usually not necessary unless the discharge is hyperpurulent. Patients with allergic conjunctivitis can be treated with topical medication, although oral allergy medication is often better tolerated in children.

If a patient has a corneal abrasion, the cornea is otherwise clear, and there is no suspicion of an intraocular foreign body, then treatment with topical antibiotics is indicated. Small foreign bodies can sometimes be removed with topical anesthetic and gentle manipulation with a cotton-tipped applicator. If a foreign body cannot be removed, or if there is any clouding of the cornea, referral is indicated.

Patients with direct ocular injuries, such as from a ball or fist, should be evaluated for a hyphema, corneal damage, and orbital fracture. Referral is indicated for most patients with nontrivial blunt ocular trauma.

Patients with red eyes who wear contact lenses should be instructed to stop wearing the lenses immediately. There is an increased risk of corneal infections in these patients, and they should be referred promptly to their eye care provider.

For any of these conditions, patients with marked pain that cannot be readily explained (e.g., from an uncomplicated corneal abrasion), or whose vision is significantly decreased, should be referred to a pediatric ophthalmologist.

What Shouldn’t Be Missed

If a patient has a corneal abrasion that does not heal in 1 to 2 days, this raises the possibility of a foreign body. Small fragments of items such as clear plastic or glass may be difficult to visualize. If the cornea becomes cloudy in any patient with a red eye, prompt referral is indicated.

Although it is rare, meninogoccal conjunctivitis may present with hyperpurulent discharge. This organism has the potential for rapid dissemination, which may progress to meningitis and sepsis. Prompt treatment is indicated to minimize this risk.

• 1. Infectious conjunctivitis. Viral conjunctivitis (“pink eye”) is the most common form of infectious conjunctivitis. It usually develops in association with a systemic viral illness, and there is frequently a history of exposure to other infected individuals. Patients with viral conjunctivitis usually have follicles on the inner lower eyelid (Figure 5–1). Bacterial conjuncitivitis is less common, though potentially more severe, than viral conjunctivitis. The discharge in viral conjunctivitis tends to be watery. It is purulent in bacterial conjunctivitis.
  
• 2. Allergic conjunctivitis. A hallmark of allergic conjunctivitis is the specific symptom of itching. If the patient is old enough to reliably articulate this symptom, it is highly likely that allergic conjunctivitis is the cause of the red eye. The conjunctiva may be mildly edematous and injected, but often the symptoms are out of proportion to the examination findings. These patients frequently have a history of other atopic disease.
  
• 3. Trauma. Mild trauma may produce a subconjunctival hemorrhage. These are benign, but may have a striking appearance of bright red blood against the white scleral background (Figure 5–2). More severe trauma may produce corneal abrasions, hyphemas, intraocular damage, and damage to the orbit and periocular structures (Figure 5–3). Corneal foreign bodies or abrasions are usually visible with a penlight, but are sometimes difficult to see.