VERNAL CATARRH

Type IV hypersensitivity reaction to external antigen

Symptoms

1. Itching is the most common complaint.

2. Thick, white, ropy mucous discharge 

3. Burning and foreign body sensation

4. Photophobia is present in cases of corneal involvement.

5. Lacrimation or watering 

signs: conjunctival signs

types

1. palpabral 

   1. conjunctival hyperemia and chemosis

   2. tarsal conjunctiva shows papillary hypertrophy

   3. there may be cobble stone papillae

2. bulbar 

   1. multiple nodules around limbus

   2. white spots composed of eosinophils seen at limbus

signs corneal:

1. Punctate epithelial erosions over the inferior third of the cornea 

2. Persistent epithelial defects

3. Plaque formation

4. Peripheral vascularization and stromal scarring

5. Predisposition to secondary bacterial and fungal infection, and  herpes simplex keratitis.

6. Keratoconus is common (about 15%)

signs cataract:

1. Presenile shield-like anterior or posterior subcapsular cataracts: increased risk of endophthalmitis due to high carriage of staph aureus

signs retinal detachment

increased risk especially after cataract surgery

Treatment

general measures

1. avoidance of antigen

2. cool compresses

3. lid hygiene 

Local treatment

1. topical mast cell stabilizers: sodium chromoglycate

2. topical antihistamines: emadastine

3. topical NSAIDS: ketorolac

4. topical steroids: flouromethalone . prednisolone

5. steroid ointment: 0.5% hydrocortisone to treat the eye lids

6. antibiotics in keratopathy along with steroids

7. acetyl cystine for mucous filaments and deposits

8. immune modulators: cyclosporin 0.05% to 2%

9. Tacrolimus 0.03% ointment can be effective in AKC for severe eyelid disease. Instillation into the fornices has been effective in modulating conjunctival

10. inflammation in refractory cases.

11. supratarsal steroid injection of triamcelone acetonide 40mg/ml in severe palpebral disease

systemic treatment

1. oral antihistamines:

2. immunosupressives: steroids cyclosporins

3. antibiotic: in blephritis. azithromycin 500mg once daily for 3 days

surgical treatment

1. superficial keratectomy to remove plaques

2. amniotic membrane grafting or lemellar keratoplasty to restore surface

3. lateral tarsorrhaphy for ulceration