What is the differential diagnosis and management plan for a patient presenting with a sty (hordeolum) of the left lower eyelid, now with associated redness, blurred vision, tearing, and mild photosensitivity?

Differential Diagnosis and Management of Complicated Hordeolum

Immediate Assessment: This Requires Urgent Ophthalmology Referral

A patient with an initial hordeolum who now develops redness, blurred vision, tearing, and photophobia has developed complications that warrant immediate ophthalmologic evaluation within 24 hours, as these symptoms represent potential vision-threatening conditions including preseptal/orbital cellulitis, keratitis, or anterior uveitis. 1

Critical Differential Diagnosis

Vision-Threatening Emergencies (Require Same-Day Ophthalmology Evaluation)

• Preseptal or Orbital Cellulitis: Eyelid swelling with pain, erythema, proptosis, pain with eye movements, movement restriction, or vision changes are warning signs requiring urgent ophthalmology referral 2, 3
• Infectious Keratitis: Severe pain, photophobia, and blurred vision demand immediate ophthalmologic consultation before any treatment initiation 3, 1
• Anterior Uveitis/Iritis: Redness, blurred vision, and photophobia can indicate intraocular inflammation requiring slit-lamp confirmation and treatment 3
• Acute Angle-Closure Glaucoma: Though less likely, mid-dilated poorly reactive pupil with severe pain and blurred vision requires immediate IOP measurement 3, 4

Non-Emergent Complications

• Blepharitis: Chronic eyelid margin inflammation that may have been unmasked or worsened by the hordeolum 2
• Conjunctivitis: Secondary bacterial or inflammatory conjunctivitis from spread of infection 2
• Dry Eye Syndrome: Burning, foreign body sensation, and photophobia with symptoms worsening throughout the day 3

Management Algorithm

Step 1: Immediate Red Flag Assessment

Perform these examinations immediately 5, 3, 1:

• Visual acuity testing (essential baseline for every patient with eye pain) 3
• Pupil examination for reactivity and afferent defects 3, 1
• Inspection for corneal damage: Look for visible corneal surface ulceration, haze, opacity, or purulent discharge 2
• Assessment of eyelid swelling: Determine if swelling extends beyond the lid margin with associated pain, erythema, or restricted eye movement 2

Step 2: Determine Urgency Level

Emergency Referral (<24 hours) if ANY of the following 2, 3, 1:

• Vision loss or significant blurred vision
• Moderate to severe eye pain (beyond irritation)
• Severe photophobia
• Mid-dilated, poorly reactive, or oval pupil
• Evidence of corneal damage on inspection
• Eyelid swelling with pain, erythema, proptosis, or restricted eye movement
• Purulent discharge

Routine Ophthalmology Referral (within 4 weeks) if 2:

• Mild to moderate symptoms without red flags
• Unresponsive to initial treatment after 1 week
• Recurrent hordeola in the same location (consider sebaceous carcinoma in elderly patients) 2

Step 3: Initial Management While Awaiting Ophthalmology

Do NOT initiate treatment before ophthalmology evaluation if red flags are present 1. Starting systemic or topical corticosteroids prior to eye exam should be avoided unless indicated for concurrent non-ophthalmological toxicity, as it may worsen infectious conditions or mask accurate diagnosis 2.

If no red flags and awaiting routine ophthalmology referral 2, 6:

• Preservative-free lubricants 2-4 times daily for symptomatic relief 2
• Warm compresses (though evidence is limited, this is standard practice) 6, 7
• Lid hygiene with gentle cleaning of lid margins 2
• Avoid topical antibiotics until ophthalmology confirms diagnosis, as minor ocular irritation and hypersensitivity reactions can occur 8

Step 4: Patient Education

Counsel patients that 2:

• Hordeolum symptoms can frequently be improved but are rarely eliminated completely
• Successful management depends on compliance with treatment regimen
• They should return immediately if symptoms worsen or new symptoms develop
• Recurrences are very common 6

Common Pitfalls to Avoid

• Never dismiss new visual symptoms as benign progression of hordeolum: Blurred vision, photophobia, and significant redness indicate complications requiring specialist evaluation 3, 1
• Do not delay ophthalmology referral for "observation": The combination of symptoms described represents potential vision-threatening conditions 1
• Avoid empiric topical steroids: These may worsen infectious keratitis or mask the severity of underlying conditions 2, 1
• Do not assume unilateral redness is always benign: Unilateral redness with pain and vision changes should prompt consideration of serious causes 2
• Never remove protruding foreign bodies if present: Use eye shield and refer urgently 4

Key Clinical Decision Point

The presence of blurred vision and photophobia in a patient with hordeolum fundamentally changes the clinical picture from a simple eyelid infection to a potential intraocular or corneal process requiring immediate specialist assessment. 1 These symptoms indicate the inflammation has extended beyond the eyelid margin and warrants urgent ophthalmologic examination including slit-lamp biomicroscopy, intraocular pressure measurement, and fluorescein staining to establish the correct diagnosis before initiating treatment 3, 1.