What are the possible causes of ocular burning and how should it be managed?

Ocular Burning: Causes and Management

Burning eye sensation most commonly results from dry eye disease, and first-line treatment consists of preservative-free artificial tears containing methylcellulose or hyaluronate applied at least twice daily, with frequency increased up to hourly based on symptom severity. 1

Primary Differential Diagnosis

Dry Eye Disease (Most Common)

• Aqueous tear deficiency presents with burning, stinging, foreign body sensation, and intermittent blurred vision 1
• Evaporative dry eye from meibomian gland dysfunction causes similar burning symptoms and coexists in the majority of dry eye patients 1, 2
• Symptoms often outweigh clinical signs on examination, particularly in mild-to-moderate disease 1

Neuropathic Ocular Pain

• Burning is a hallmark descriptor of neuropathic ocular pain (NOP), along with stinging or aching 1
• NOP develops after ocular surgeries (refractive surgery, cataract extraction), post-infection (herpes zoster), or from chronic ocular surface inflammation 1
• Key diagnostic clue: symptoms persist despite appropriate treatment and resolution of tear film abnormalities 1
• Patients typically report photophobia and wind hyperalgesia alongside burning 1

Allergic Conjunctivitis

• Burning accompanied by itching, hyperemia, and discharge suggests allergic etiology 3, 4
• Inflammation predominates over nerve injury in this condition 4

Chemical or Thermal Exposure

• Acute onset burning after exposure to cleaning products, pesticides, or environmental toxins 5
• Chemical burns represent true emergencies requiring immediate copious irrigation 6, 7

Blepharitis and Meibomian Gland Dysfunction

• Lid margin inflammation causes burning, particularly with Demodex infestation 1, 2
• Often coexists with dry eye disease 1, 2

Diagnostic Approach

Initial Assessment

• Measure visual acuity with current correction before other examination 8
• Slit-lamp examination with fluorescein staining to assess corneal epithelium, tear film break-up time, and tear meniscus height 1
• Evaluate lid margins and lashes for blepharitis, meibomian gland dysfunction, or Demodex 1, 2
• Assess symptom-to-sign ratio: symptoms far exceeding objective findings suggest neuropathic component 1

Specialized Testing for Neuropathic Pain

• Anesthetic challenge test: instill topical anesthetic when pain is present 1
  • Pain improvement suggests nociceptive or peripheral neuropathic component 1
  • Persistent pain suggests central or non-ocular cause 1
• Consider questionnaires: Neuropathic Pain Symptom Inventory (NPSI)-Eye or Ocular Pain Assessment Survey (OPAS) 1

Autoimmune Evaluation (When Indicated)

• For suspected Sjögren's syndrome: Schirmer test (<5 mm in 5 minutes), ocular staining score (≥5), anti-Ro/SSA antibodies 1
• Diagnosis requires ≥4 points on European-American Consensus criteria with dryness of eyes/mouth for ≥3 months 1

Staged Treatment Algorithm

Step 1: Environmental Modifications and First-Line Therapy

• Eliminate cigarette smoke exposure completely, as smoking impairs the lipid layer of the tear film 1, 2
• Humidify ambient air and use side shields on spectacles to reduce airflow across the ocular surface 1, 2
• Position computer screens below eye level, take breaks every 20 minutes, and consciously blink >10 times/minute 1, 2
• Preservative-free artificial tears (methylcellulose or hyaluronate-based) at least twice daily, increased to hourly as needed 1, 2
• Warm compresses for 5-10 minutes twice daily followed by gentle lid massage to express meibomian gland secretions 1, 2
• Eyelid hygiene with tea tree oil for Demodex if present 1, 2
• Review and modify offending medications: antihistamines, anticholinergics, certain antidepressants, topical glaucoma medications 1, 2

Step 2: Anti-Inflammatory Therapy (Moderate Dry Eye)

• Cyclosporine 0.05% ophthalmic emulsion twice daily prevents T-cell activation and inflammatory cytokine production 1, 2
  • Success rates: 74% mild, 72% moderate, 67% severe dry eye 2
  • Ocular burning occurs in ~17% but is generally well-tolerated 2
• Lifitegrast 5% ophthalmic solution twice daily blocks LFA-1/ICAM-1 interaction, preventing T-cell activation 1, 2
• Short-term topical corticosteroids (maximum 2-4 weeks) for rapid symptom control, but limited duration to avoid infections, increased intraocular pressure, and cataracts 1, 2

Step 3: Tear Conservation (Refractory Cases)

• Punctal occlusion with temporary silicone plugs to assess benefit before permanent thermal or laser cautery 1, 2
• Moisture chamber spectacles/goggles to reduce environmental evaporation 1, 2

Step 4: Advanced Therapies (Severe Dry Eye)

• Autologous serum eye drops improve ocular irritation and corneal staining in severe cases 1, 2
• Oral secretagogues: pilocarpine 5mg four times daily or cevimeline for Sjögren's syndrome 1, 2
• In-office thermal pulsation devices (LipiFlow, TearCare) for meibomian gland dysfunction 2
• Intense pulsed light (IPL) therapy for meibomian gland dysfunction 2
• Amniotic membrane grafts for severe ocular surface disease 2

Neuropathic Ocular Pain Treatment

Peripheral Neuropathic Pain

• Topical nerve regenerative therapies: autologous serum tears 1

Central Neuropathic Pain

• Oral neuromodulators: pregabalin, gabapentin, duloxetine, amitriptyline, nortriptyline, or low-dose naltrexone 1
• Requires 3-4 months at therapeutic dose to see pain reduction 1
• Periorbital botulinum toxin A injections for light sensitivity and headache 1
• Periocular nerve blocks (corticosteroid with long-acting sodium channel blocker) for cutaneous allodynia or post-surgical pain 1

Adjunctive Management

• Address concomitant anxiety, depression, and mood disorders, as corneal nerves connect to emotional processing areas of the brain 1
• Set realistic expectations early and encourage treatment continuation despite lack of immediate relief 1

Critical Pitfalls to Avoid

• Do not use preserved artificial tears more than 4 times daily, as preservatives cause ocular surface toxicity 1, 2
• Do not extend topical corticosteroid therapy beyond 4 weeks to prevent serious complications 1, 2
• Do not overlook underlying blepharitis or meibomian gland dysfunction, which perpetuates symptoms despite other treatments 1, 2
• Do not dismiss symptoms when signs are minimal—consider neuropathic ocular pain when symptom-to-sign ratio is disproportionate 1
• Do not delay ophthalmology referral for suspected uveitis, as progression to vision loss can occur 1

When to Refer to Ophthalmology

• Symptoms persisting despite appropriate first-line therapy 1
• Suspected neuropathic ocular pain requiring anesthetic challenge test 1
• Refractory or severe ocular dryness (ocular staining score >5) 1
• Suspected uveitis (eye pain, blurred vision, photophobia, headaches) 1
• Chemical or thermal burns requiring urgent evaluation 6, 7