Treatment of Eye Pain
Treatment of eye pain must be guided by identifying the underlying cause through systematic evaluation, with immediate ophthalmology referral for vision-threatening conditions such as bacterial keratitis, acute angle-closure glaucoma, or orbital cellulitis. 1, 2
Initial Diagnostic Approach
The first critical step is distinguishing between nociceptive (tissue damage) and neuropathic (nerve dysfunction) sources of pain through comprehensive ocular surface examination. 1
Key Diagnostic Maneuvers
Perform the "anesthetic challenge test" when neuropathic pain is suspected: instill topical anesthetic while pain is present. If pain improves, this suggests nociceptive or peripheral neuropathic pain; if unchanged, suspect central or non-ocular causes. 1
Assess for vision-threatening conditions first: bacterial keratitis (infiltrate with suppuration), acute angle-closure glaucoma, scleritis, anterior uveitis, and infectious keratitis all require urgent ophthalmology consultation. 1, 2, 3
Evaluate ocular surface parameters: tear film stability, aqueous tear deficiency, inflammation, epithelial erosions, and meibomian gland dysfunction can all trigger corneal nociceptors. 1
Treatment Based on Etiology
Bacterial Keratitis (Infectious Pain)
For central or severe bacterial keratitis, initiate frequent topical fluoroquinolone monotherapy immediately (loading dose every 5-15 minutes, then hourly). 1
Single-drug fluoroquinolone therapy (ciprofloxacin 0.3%, ofloxacin 0.3%, or levofloxacin 1.5%) is as effective as fortified combination therapy for most cases. 1
Add cycloplegic agents (e.g., cyclopentolate, homatropine) to decrease synechiae formation and reduce pain when substantial anterior chamber inflammation is present. 1
Fortified topical antibiotics should be considered for large and/or visually significant infiltrates, especially with hypopyon present. 1
Neuropathic Ocular Pain (NOP)
Treatment depends critically on whether nerve dysfunction is peripheral versus central. 1
Peripheral Neuropathic Pain
For peripheral corneal neuropathic pain, use topical nerve regenerative therapies as first-line treatment, specifically autologous serum tears. 1
Anti-inflammatory therapy with topical loteprednol is recommended as first-line adjunctive treatment. 1
Consider self-retained or cryopreserved amniotic membrane (CAM) for rapid symptomatic relief in refractory cases with severe hyperalgesia. 1
Therapeutic bandage contact lenses or scleral lenses (PROSE) may provide immediate relief by shielding corneal nociceptors from environmental stimuli, though infection risk limits long-term use. 1
Central Neuropathic Pain
For central neuropathic pain or cases with systemic comorbidities, initiate oral neuromodulators as first-line systemic therapy. 1
Tricyclic antidepressants (TCAs): Start nortriptyline 10-25 mg at bedtime, increase every 3-7 days to 25-100 mg as tolerated (preferred over amitriptyline due to fewer side effects). 1
Anticonvulsants: Gabapentin or pregabalin are alternatives; carbamazepine 200 mg at night, gradually increased by 200 mg every 7 days to 400-1200 mg divided doses for trigeminal neuralgia-type pain. 1
Other options include duloxetine, amitriptyline, nortriptyline, or low-dose naltrexone, used alone or in combination. 1
Critical Timing Consideration
All neuromodulators require 3-4 months at therapeutic dose to achieve pain reduction—set expectations early and encourage treatment continuation despite lack of immediate relief. 1
Adjunctive Strategies for Specific Symptoms
For photophobia and headache: Consider transcutaneous electrical nerve stimulation devices or periorbital botulinum toxin A injections (migraine-type strategies). 1
For cutaneous allodynia or postsurgical pain: Periocular nerve blocks with corticosteroid plus long-acting sodium channel blocker. 1
Ocular Surface Disease-Related Pain
Address underlying tear deficiency and inflammation systematically. 1
Treat aqueous tear deficiency with preservative-free lubricants and consider punctal plugs after initial anti-inflammatory therapy. 1
Manage meibomian gland dysfunction with warm compresses, lid massage, and consider oral doxycycline or azithromycin. 1
Topical cyclosporine 0.05% or lifitegrast 5% for chronic inflammatory conditions. 1
Multidisciplinary Approach for Chronic Pain
Neuropathic ocular pain warrants involvement of ophthalmologists, pain specialists, neurologists, and mental health professionals. 1
Address concomitant anxiety, depression, and mood disorders that commonly accompany chronic ocular pain. 1
Consider complementary therapies: acupuncture, cognitive behavioral therapy, or hypnosis as adjuncts. 1
Common Pitfalls to Avoid
Do not dismiss symptoms that outweigh clinical signs—this pattern strongly suggests neuropathic pain rather than inadequate treatment of surface disease. 1
Avoid preservative-containing formulations in severe hyperalgesia—use preservative-free preparations or compounded methylprednisolone 1%. 1
Do not expect immediate pain relief with neuromodulators—failure to set appropriate expectations leads to premature treatment discontinuation. 1
Recognize that ocular surface abnormalities can coexist with neuropathic pain—treat both components simultaneously. 1