23. Allergic and autoimmune conjunctivitis. Vernal conjunctivitis. Lymphatic keratoconjunctivitis. Degenerations the conjunctiva - pinguecula and pterygium. Dry eye syndrome.

Allergic and autoimmune conjunctivitis. Spring catarrh. Lymphatic Keratoconjunctivitis

Allergic conjunctivitis: It is the inflammation of conjunctiva due to allergic or hypersensitivity reactions.

Types:

1. Simple allergic conjunctivitis

• Hay fever conjunctivitis
• Seasonal allergic conjunctivitis
• Perennial allergic conjunctivitis

2. Vernal keratoconjuctivitis (aka spring catarrh)
3. Atopic keratoconjunctivitis
4. Giant papillary conjunctivitis
5. Phlyctenular keratoconjunctivitis (aka lymphatic keratoconjunctivitis) 6. Contact dermoconjunctivitis

Simple allergic conjunctivitis:

• A mild, non-specific allergic conjunctivitis Etiology:
• Hay fever conjunctivitis:- common allergens are pollens, grass, and animal dandruff o Seasonal allergic conjunctivitis – is a response to seasonal allergens such as grass pollens
• Perennial allergic conjunctivitis – is a response to perennial allergens such as house dust and mite.
• Clinical picture: o Itching in the eye, hyperaemia, lid oedema, and conjunctival oedema (chemosis)
• Treatment
• Elimination of allergens if possible, antihistamines, local palliative measures

VERNAL KERATOCONJUNCTIVITIS (OR SPRING CATARRH)

• It is a recurrent, bilateral, self-limiting conjunctivitis having a periodic seasonal incidence. It is also labeled as ‘Warm weather conjunctivitis’.
• Etiology o Exogenous allergens such as grass pollens
• Clinical picture o Marked burning and itching sensation which is usually intolerable o Mild photophobia, lacrimation, discharge and heaviness of lids o It is often self-limiting
• Treatment
• Topical or oral sterioids, mast cell stabilizers, topical or systemic antihistamines. Dark goggles to prevent photophobia

PHLYCTENULAR OR LYMPHATIC KERATOCONJUNCTIVITIS

• It is a characteristic nodular affection occurring as an allergic response of the conjunctival and corneal epithelium to some endogenous allergens
• Etiology o Delayed hypersensitivity response to endogenous microbial proteins ▪ Eg. Tuberculous proteins, staphylococcus proteins Pathology

1. Stage of nodule formation
2. Stage of ulceration
3. Stage of granulation
4. Stage of healing

• Clinical pictures o discomfort in the eye, irritation and reflex watering, hyperemia, presence of nodules, and ulceration
• Treatment
• Topical steroids, antibiotic drops and ointment to treat secondary infection, atropine