Vernal Keratoconjunctivitis (vkc)

Vernal Keratoconjunctivitis (VKC) • It is a chronic , bilateral conjunctival inflammatory condition found in individuals predisposed by their atopic background. It is recurrent, interstitial inflammation of the conjunctiva of periodic seasonal incidence, self limiting disease/ condition usually due to exogenous allergens.

• Characterized by flat topped papillae usually on the tarsal conjunctiva resembling cobble stones in appearance , a gelatenous hypertrophy of the limbal conjunctiva, either discrete or confluent, and a distinctive type of keratitis , associated with itching , redness of the eyes lacrimation and mucinous or lardaceous discharge usually containing eosinophils

Epidemiology • Sporadically occurring with a wide geographical incidence. Its more common in India and the tropics than in U.K. Colored races are particularly prone to limbal form of disease. • It is essentially a disease of youth occurring most frequently between ages of 6 and 20 years.

• Sex incidence – Very high percentage of cases are seen in males. • Family History of allergy is found in 40 – 60 % cases.

Etiology • Three theories 1. Due to action of physical factors (as heat, humidity and light) 2. Disorder of the endocrine glands associated with vagotonic state 3. manifestation of an allergic condition. Most affected people show a marked hypersensitivity to a variety of antigens (pollen, animal inhalants, ingestants etc)

Symptoms • Severe itching, photophobia, foreign body sensation, ptosis, thick mucous discharge, blepharospasm, burning, and typical stringy discharge . • Discharge is scanty, thick, ropy and lardaceous, dirty white or cream colored.

Signs • The signs are confined to conjunctiva and cornea; the skin of the lids are not involved. • Types – Palpabral form – Limbal/ Bulbar form – Mixed type

Palpabral VKC Conjunctiva develops a papillary response in the upper tarsal conjunctiva. Conjunctiva is congested later on becomes milky. Tarsal papillae are discrete larger than 1 mm in diameter, flat tops , they are cobblestone in appearance.

Limbal / Bulbar Form • In limbal or bulbar form the first change is usually a thickening, broadening and opacification of the limbus which overrides the corneal periphery as a semitranslucent hood. This develop mostly at the upper margin of the cornea • Limbal papillae tend to be gelatinous and confluent

• Limbal Nodules – Their most common site is in the palpabral aperture, nasally and temporally. In the raised mass, whitish Horner- Trantas’s spots may occur at any stage. Horner Trantas dots are collection of epithelial cells and eosinophils. • These changes may lead to superficial corneal vascularization.

Corneal Findings • Punctate Epithelial Keratitis • Horizontally oval ulcer in upper part of cornea called Shield Ulcer • Peripheral superficial gray white deposition termed Pseudogeronton.

Pathogenesis • Biopsy of tarsal papilla in VKC reveals that epithelium contain large number of mast cells and eosinophils. Substantia properia contains elevated number of mast cells, also contains CD4 + T cells. Mast cells contains basic fibroblast growth factor • Cytology shows more eosinophils and neutrophils, IgE and IgG have been isolated from tears. Histamins and trytase are elevated in tears • Protein deposition diffusely in conjunctiva

• The flat-topped nodules are hard , and consist chiefly of dense fibrous tissue , but the epithelium over them is thickened , giving rise to the milky hue. Histologically they are hypertrophied papillae, not follicle. Eosinophils are present in them in great numbers. In addition , infiltration with lymphocytes, plasma cells , macrophages, and basophils may also be seen.

Diagnosis • History • Clinical findings (young boys living in warm climates presenting with intense photophobia, ptosis and gaint papillae)

TREATMENT 1. Avoidance of allergen 2. Local Treatment a. Steroids – Patients with significant seasonal exacerbation , a short term high dose pulse regimen of topical steroid is necessary. Dexamethasone 0.1% or Prednisolon Phosphate 1% , 8 times for one week brings excellent result, tapered rapidly.

b. Mast Cell stabilizer: Cromolyn sodium, a mast cell stabilizer or a dual acting drug such as Olopatidine, Ketotifen or Azelastine (mast cell stabilization and antihistamine) c. Topical Cyclosporin-A (0.05%) twice daily, it decreases the release of interlukin-2, reduces expansion of T cell clones.

Treatment of Corneal Shield Ulcer: Antibiotic- steroid ointment and occlusion. If plaque forms – superficial keratectomy Phototherapeutic Keratectomy (PTK) and Keratectomy with amniotic membrane graft placement.

Surgical Treatment Cryo-ablation of upper tarsal cobble stones – but may lead to lid and tear film abnormalities. Injection of short term or long term acting steroids into tarsal papilla has been shown effective in reducing their size.

3. Systemic Treatment: a. Non sedating antihistaminic b. Oral Aspirin (high dose of 2400 mgm daily) 4. Climatotherapy