Vernal keratoconjunctivitis

Vernal keratoconjunctivitis (VKC) is a chronic, severe allergy that affects the surfaces of the eyes. It most commonly occurs in boys living in warm, dry climates. Attacks associated with VKC are common in the spring (hence the name "vernal") and summer but often reoccur in the winter. Signs and symptoms usually begin before 10 years of age and may include hard, cobblestone-like bumps (papillae) on the upper eyelid; sensitivity to light; redness; sticky mucus discharge; and involuntary blinking or spasms of the eyelid (blepharospasm). The condition usually subsides at the onset of puberty. It is caused by a hypersensitivity (allergic reaction) to airborne-allergens. Management focuses on preventing "flare ups" and relieving the symptoms of the condition.

A review of available literature currently does not yield information about the overall incidence (the rate of occurence of new cases) of vernal keratoconjunctivitis (VKC). VKC has a wide geographical distribution and varying prevalence (the total number of cases in a given population at a specific time) has been reported in different ethnic groups. It is most common in young males living in dry, hot climates such as in Mediterranean areas, central and west Africa, the Middle East, Japan, the Indian subcontinent and South America. It is also seen in Western Europe (including the UK and Sweden), Australia and North America - although the prevalence in these countries has probably increased due to migration of more susceptible populations. One survey suggests VKC may have a prevalence rate of 3.2 per 10,000 individuals in Western Europe. Another study involving over 400 affected individuals only in an area of Northern Italy reported that the average incidence independent of gender and age was 1 in 100,000 new cases. The authors reported a higher rate in males under 16 years of age (10 in 100,000) compared with females (4.2 in 100,000).

Vernal keratoconjunctivitis (VKC) generally resolves spontaneously after puberty without any further symptoms or visual complications. However, the development of corneal ulcers (in approximately 9.7% of affected individuals), cataract or glaucoma can potentially cause permanent vision loss. Beginning treatment immediately after receiving the diagnosis of VKC is very important because the longer an individual has complications from the disease, the greater the chances of developing cataracts or permanent blindness. It has been reported that the size of the papillae is directly related to the probability of persistence or worsening of symptoms (i.e. the larger the papillae, the worse the prognosis is). It has also been reported that the bulbar forms of VKC have a worse long-term prognosis than the tarsal forms.

Management of vernal keratoconjunctivitis (VKC) focuses on preventing allergic attacks as well as relieving the signs and symptoms of the condition. It is often recommended that affected individuals try to avoid the agent that causes the allergy (if possible); wear dark sunglasses in the daytime; avoid dust; and stay inside on hot afternoons. Eye drops that affect the amount of histamine released by immune system cells (called mast cell stabilizers) may be used at the beginning of the season or at the first sign of a "flare-up" to prevent severe symptoms; however, they are not considered effective at relieving symptoms. Topical eye drops are generally preferred as the first source of treatment. Cold compresses, artificial tears, ointments and/or topical antihistamines may help. Non-steroid anti-inflammatory drugs (NSAIDS) may relieve symptoms in moderate cases; topical steroids are typically only used for more severe cases because long-term use can cause glaucoma.

A few prescription drugs may also be available for the treatment of VKC; these include cromolyn sodium, lodoxamide tromethamine and Levocabastine. Oral administration of montelukast, a drug usually prescribed for asthma, has also been shown to be an effective treatment of VKC. For more information about these drugs and their availability, individuals should speak with their health care providers.