What is the differential diagnosis for a 13-year-old male with right eye pain, periorbital swelling, decreased visual acuity (20/40), and elevated intraocular pressure (23 mmHg), without erythema or photophobia?

Differential Diagnosis and Critical "Don't Miss" Conditions

This 13-year-old requires urgent ophthalmology evaluation and imaging to rule out orbital cellulitis, acute angle-closure glaucoma, and uveitis—all vision-threatening emergencies that can present with periorbital swelling, elevated IOP, and decreased visual acuity. 1, 2

Immediate Life/Vision-Threatening Diagnoses (Don't Miss)

Orbital Cellulitis

• Most critical diagnosis to exclude given the combination of periorbital swelling and eye pain in a pediatric patient 1, 3
• Key distinguishing features to assess:
  • Proptosis, ophthalmoplegia, or pain with eye movements are red flags mandating urgent CT imaging 1
  • Relative afferent pupillary defect (RAPD) indicates orbital involvement requiring immediate intervention 1
  • Fever, sinusitis symptoms, or systemic signs increase suspicion 1, 4
• Critical pitfall: The absence of erythema does NOT exclude orbital cellulitis—postseptal infection can present without marked external inflammation 1, 4
• Imaging required: CT orbits with IV contrast is the initial study of choice to differentiate preseptal from postseptal cellulitis and identify abscesses 5, 1
• Urgent action: If orbital cellulitis is confirmed, empiric IV antibiotics (ceftriaxone plus clindamycin or vancomycin if MRSA risk) must be initiated immediately 1
• Vision loss can occur rapidly—one case series documented progression from 20/250 to no light perception within 24 hours despite treatment 4

Acute Angle-Closure Glaucoma

• IOP of 23 mmHg is borderline elevated and warrants gonioscopy to assess angle status 6, 7
• Classic presentation includes:
  • Severe eye pain (supraorbital/frontalis region matches this patient) 6
  • Decreased visual acuity 6
  • Mid-dilated, non-reactive pupil (must be assessed) 6
  • Corneal edema on slit-lamp examination 5
• However, the absence of photophobia is atypical for acute angle-closure, which usually presents with photophobia, nausea, and seeing halos around lights 6
• Action required: Urgent gonioscopy to evaluate angle anatomy; if angle-closure confirmed, immediate IOP reduction with topical and systemic agents, followed by laser peripheral iridotomy 6, 7

Uveitis (Anterior, Posterior, or Pan-uveitis)

• Presents with eye pain, decreased visual acuity (20/40 matches Grade 2 criteria), and can cause elevated IOP 5
• Critical distinction: Photophobia is typically present in uveitis but is ABSENT in this patient, making this diagnosis less likely 5, 1
• Requires urgent ophthalmology referral within 2 days if Grade 2 suspected 5
• Slit-lamp examination should assess for:
  • Anterior chamber cells and flare 5
  • Keratic precipitates 5
  • Posterior synechiae 5
• Warning: Posterior uveitis can be asymptomatic but still progress to vision loss 5

Secondary Differential Considerations

Steroid-Induced Ocular Hypertension

• Must obtain medication history extending back weeks to months 2, 8
• Topical corticosteroids can cause IOP elevation, particularly with:
  • Duration >1 month 8
  • Frequency ≥2 drops/day 8
  • Potent formulations (prednisolone, difluprednate) 8
• Management if confirmed: Discontinue or rapidly taper steroids, initiate aqueous suppression with timolol, topical carbonic anhydrase inhibitor, and brimonidine 8

Corneal Edema with Elevated IOP

• Elevated IOP (from any cause) can produce corneal edema, leading to decreased visual acuity 5
• Typical symptoms include:
  • Blurred vision with diurnal variation (worse upon waking) 5
  • Foreign body sensation 5
  • Photophobia is usually present (absent in this patient) 5
• Slit-lamp examination should assess for:
  • Corneal thickness and clarity 5
  • Descemet's folds or Vogt striae 5
  • Epithelial edema or bullae 5

Preseptal Cellulitis

• Less concerning than orbital cellulitis but still requires evaluation 5, 1
• Key distinguishing features:
  • No proptosis, no ophthalmoplegia, no pain with eye movements 5, 1
  • Vision typically normal (this patient has 20/40) 1
  • Eyelid swelling with pain and erythema (erythema is absent in this patient) 5
• Warning signs that indicate progression to orbital cellulitis: proptosis, movement restriction/diplopia, vision changes 5

Blepharitis with Secondary Inflammation

• Can cause periorbital puffiness and discomfort 5
• However, blepharitis does NOT typically cause:
  • Elevated IOP 5
  • Decreased visual acuity to 20/40 5
  • Supraorbital/frontalis pain 5
• This diagnosis is unlikely given the clinical presentation 5

Medication-Induced Periorbital Edema

• Review complete medication history, including:
  • Imatinib (causes periorbital edema in up to 70% of patients) 2
  • ACE inhibitors (angioedema can persist 6 weeks after discontinuation) 2
  • Topical glaucoma medications, NSAIDs, antibiotics 2
• However, medication-induced edema typically does NOT cause:
  • Elevated IOP 2
  • Decreased visual acuity 2
  • Eye pain 2

Diagnostic Algorithm

1. Immediate ophthalmology consultation to perform:

   • Slit-lamp examination for anterior chamber inflammation, corneal edema, angle assessment 5, 1
   • Gonioscopy to evaluate angle anatomy 6, 7
   • Dilated fundus examination to assess optic nerve 6
   • Assessment for proptosis, RAPD, and extraocular motility 1

2. If any red flags present (proptosis, ophthalmoplegia, RAPD, pain with eye movements):

   • Urgent CT orbits with IV contrast 5, 1
   • Do NOT delay imaging 1
   • Initiate empiric IV antibiotics if orbital cellulitis suspected 1

3. If angle-closure suspected on gonioscopy:

   • Immediate IOP reduction with topical beta-blocker, alpha-agonist, carbonic anhydrase inhibitor 8, 6
   • Consider oral acetazolamide for rapid IOP reduction 8
   • Laser peripheral iridotomy once IOP controlled 6, 7

4. If uveitis confirmed:

   • Coordinate treatment with ophthalmologist (topical corticosteroids, cycloplegic agents) 5
   • Hold any immune checkpoint inhibitors if applicable 5

Critical Pitfalls to Avoid

• Do NOT assume absence of erythema excludes orbital cellulitis—postseptal infection can present without marked external signs 1, 4
• Do NOT assume absence of photophobia excludes serious pathology—posterior uveitis and orbital cellulitis can present without photophobia 5, 1
• Do NOT delay CT imaging if any proptosis, visual changes, or ophthalmoplegia present—orbital cellulitis requires urgent intervention to prevent permanent vision loss 1, 4
• Do NOT overlook medication history—steroid-induced IOP elevation is common and reversible if identified early 8
• Do NOT assume IOP of 23 mmHg is "normal"—this is borderline elevated and requires gonioscopy to assess for angle-closure 6, 7