What are the features and management of vernal keratoconjunctivitis?

Vernal Keratoconjunctivitis: Clinical Features and Management

Clinical Features

Vernal keratoconjunctivitis (VKC) is a severe, bilateral, seasonally recurrent allergic eye disease predominantly affecting young males in warm climates, characterized by giant papillae on the upper tarsal conjunctiva (cobblestoning), limbal gelatinous infiltrations (Horner-Trantas dots), and severe symptoms including intense itching, photophobia, thick ropy mucous discharge, and tearing. 1, 2

Key Clinical Presentations

Morphological Forms:

• Palpebral form: Giant papillae on upper tarsal conjunctiva creating a cobblestone appearance 1, 2
• Limbal form: Gelatinous infiltrations around the limbus with Horner-Trantas dots (collections of eosinophils and epithelial cells) 1, 3
• Mixed form: Combination of both palpebral and limbal features 2

Characteristic Symptoms:

• Severe eye itching and irritation (most consistent symptom) 1
• Constant tearing and photophobia 1
• Thick, white, ropy mucous discharge 1, 2
• Red eye with severe conjunctival injection 1
• Foreign body sensation and pain (especially with corneal involvement) 4

Distinctive Clinical Signs:

• Pseudogerontoxon (limbal pigmentation) 3
• Perilimbal hyperpigmentation 3
• Eosinophils as predominant cells in tears and discharge 1

Sight-Threatening Complications

VKC can lead to permanent visual loss if untreated, with corneal complications being the most serious concern. 1, 2

• Shield ulcers: Corneal ulceration requiring urgent management 1, 3, 4
• Corneal scarring: Permanent vision impairment from chronic inflammation 1, 3
• Steroid-induced complications: Increased intraocular pressure, glaucoma, cataracts, and infections from chronic topical corticosteroid use 1, 4

Management Algorithm

First-Line Therapy

Start with topical mast cell stabilizers and antihistamines as maintenance therapy, with cromolyn sodium 4% (1-2 drops 4-6 times daily) being FDA-approved specifically for VKC. 5

• Cromolyn sodium requires regular administration at consistent intervals for effectiveness 5
• Symptomatic improvement typically occurs within days, but treatment may require up to 6 weeks 5
• Continue therapy as long as needed to sustain improvement 5
• Dual-acting agents like lodoxamide and olopatadine are alternatives, though frequently insufficient for severe cases 1

Second-Line Therapy for Flare-Ups

Topical corticosteroids are often required during acute exacerbations, as conventional allergy therapy is generally inadequate for VKC. 1, 2

• Corticosteroids may be used concomitantly with cromolyn sodium 5
• Monitor intraocular pressure and perform pupillary dilation periodically to evaluate for glaucoma and cataracts 6
• Taper corticosteroids once inflammation is controlled 6
• Critical pitfall: Prolonged corticosteroid use leads to serious complications including glaucoma, cataracts, and increased infection risk 1, 4

Third-Line: Topical Immunomodulators

For severe, chronic, or steroid-dependent VKC, topical immunomodulators (cyclosporine or tacrolimus) are effective anti-steroidal alternatives. 6, 3, 2

• Cyclosporine 0.05% to 1%: Effective for cases failing conventional therapy 6
• Tacrolimus 0.03% or 0.1%: Randomized trials demonstrate efficacy in patients who failed corticosteroids, cyclosporine, and antiallergy medications 6
  • Use 0.03% for children 2-15 years old
  • Use 0.03% or 0.1% for patients ≥16 years old 6
• Pimecrolimus cream 1%: For eyelid involvement in patients ≥2 years old 6
• Important caveat: These agents may increase susceptibility to herpes simplex keratitis 6
• Rare association with skin cancer or lymphoma 6

Fourth-Line: Systemic and Advanced Therapies

For severe sight-threatening disease unresponsive to topical therapy, consider supratarsal corticosteroid injection or systemic immunosuppression. 6

• Systemic options (rarely warranted): montelukast, aspirin, interferons, oral cyclosporine, or tacrolimus 6
• Surgical intervention: Reserved for complications like shield ulcer debridement or advanced glaucoma/cataracts, requiring ophthalmologist expertise 1, 4

Critical Management Principles

VKC should be controlled prior to corneal cross-linking procedures to decrease the risk of developing sterile keratitis. 6

General strategies to minimize corticosteroid use should be employed throughout treatment to prevent serious complications. 6

• Frequency of follow-up depends on disease severity and treatment used 6
• Contact lens wear is contraindicated during active VKC 5
• Patients should avoid contact lenses while exhibiting signs and symptoms of VKC 5

Pathophysiology Context

VKC involves Th2 cell-mediated immune processes with overexpression of IL-4, IL-5, IL-9, IL-13, and IL-31, plus mast cell activation recruiting eosinophils 3. Both IgE-dependent (type I) and IgE-independent (type IV) allergic mechanisms contribute to disease pathogenesis 2. This complex immunopathology explains why simple antihistamine therapy is inadequate and why immunomodulators are effective 1, 2.