Keratoconjunctivitis, Atopic ?>

Keratoconjunctivitis, Atopic

Keratoconjunctivitis, Atopic

Introduction
Background

Atopic keratoconjunctivitis (AKC) is a relatively uncommon but potentially blinding ocular condition. In 1952, Hogan described AKC as a bilateral conjunctivitis occurring in 5 male patients with atopic dermatitis. Originally described to flare with worsening dermatitis, Foster et al noted that some patients’ ocular involvement evolves independent of dermatitis.1

AKC is associated with a 95% prevalence of concomitant eczema and an 87% prevalence of asthma. Other than AKC, common ocular atopic phenomena include allergic conjunctivitis, giant papillary conjunctivitis, and vernal keratoconjunctivitis.

Pathophysiology
Atopy refers to hypersensitivity in patients with familial histories of allergic disease. Individuals with atopy often have environmental allergies, allergic asthma, rhinitis, and atopic dermatitis or eczema. Less commonly, they exhibit food allergies, urticaria, and nonhereditary angioedema. Immunoglobulin E (IgE) is the serum mediator of the exuberant responses. Hypersensitivity reactions associated with types I and IV contribute to the inflammatory changes of the conjunctiva and the cornea that are found in AKC. During exacerbations, patients have increased tear and serum IgE levels and increased numbers of circulating B cells; T-cell levels are depressed.
Frequency
International

Atopy affects 5-20% of the general population. AKC occurs in 20-40% of individuals with atopic dermatitis.
Mortality/Morbidity

Decreased vision and blindness result from chronic superficial punctate keratitis, persistent epithelial defects, corneal scarring or thinning, keratoconus, cataracts, and symblepharon formation. The use of corticosteroids to medically treat AKC can further promote the development of cataracts, glaucoma, and secondary corneal infections.
Sex

This condition is more prevalent in men than in women.
Age

Peak age of incidence is in persons aged 30-50 years. The age range is from the late teenaged years to 50 years.
Clinical
History

Look for the following in past medical history:
Chronic or chronically relapsing atopic disease
Dermatitis
Asthma
Rhinitis
Ocular symptoms with little or no seasonal variation (as opposed to vernal conjunctivitis that is seen only in warm weather)
Itching
Tearing
Ropy discharge
Burning
Photophobia
Decreased vision
Physical
Periorbita – Dennie-Morgan folds (linear lid folds secondary to chronic eye rubbing) and Hertoghe sign (absence of lateral eyebrows)
Lids – Thickening and tylosis, crusting, edema, fissures, ptosis, and staphylococcal blepharitis
Conjunctiva
Small- or medium-sized papillae, hyperemia, edema, excessive mucin, and limbal Trantas dots (clusters of necrotic eosinophils, neutrophils, and epithelial cells)
Formation of keratinization, cicatrization, and symblepharon in advanced disease
Cornea
Punctate epitheliopathy and keratitis, persistent epithelial defects, shield-shaped ulcers, anterior stromal scarring, and micropannus
Extensive peripheral corneal vascularization in later stages
Higher incidence of keratoconus (16%) and recurrent herpes simplex keratitis associated with AKC
Lens – Posterior or anterior subcapsular shield-shaped cataracts
Fundus – Degenerative vitreous changes and retinal detachment

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