Allergic Eye Disease

Unless the allergy is due to an easily removable cause like a glaucoma eye drop, or wearing a contact lens or a protruding suture, it can be difficult to identify exactly which allergen(s) are causing the problem in allergic eye disease.

Identifying definite lifestyle changes which occurred immediately before the onset of the ocular allergy can help, for example moving home to a carpeted floor instead of wooden floorboards, suggests house dust mite allergy.

Previous studies indicate that skin prick testing results do not accurately correlate in allergic conjunctivitis, so it is not currently recommended.

However if a patient wishes nevertheless to identify which agents or eye make up they may be allergic to, referral to a consultant expert in skin prick testing is possible.

Use a vacuum with a HEPA filter to reduce dust in your home, try keeping pets out of the bedroom to reduce dander exposure.

If pollen and seasonal allergens are the cause, sunglasses and a wide brim hat can reduce the amount of allergen that lands in the eyes, and saline eye drops to wash away the allergens can help.

If you use contact lenses, in general, do not wear lenses until symptoms have gone, however you may be advised by your eye specialist if you can wear contact lenses with certain types of eye drops.

Try not to rub your eyes, as this causes more inflammation. Use an artificial tear drop to wash away the itchy feeling whenever possible, rather than rubbing the eyes.

Try not to “fish” out mucus from the eyes, as this causes more mucus to be produced. Use an artificial tear drop to cleanse the mucus away.

Cool compresses with a towel or flannel soaked in cold water can help.

• over-the-counter anti-histamine tablets (e.g. cetirizine, loratadine) and
• over-the-counter mast cell stabilizer eye drops containing sodium cromoglycate 2%, 1 drop 2-4x/day, can help.

Long term intake of oral anti-histamine tablets (for more than 2 months continuously) can lead to dry eye due to reduced watery (aqueous) tear production.

Sodium cromoglycate eye drops are available preservative-free and these can be used with contact lenses in place. Preserved sodium cromoglycate eye drops in a bottle can be used morning and night in contact lens wearers, before inserting and after removing contact lenses each day.

Over the counter anti-histamine eye drops often contain a vasoconstrictor which makes the eyes white (e.g. antazoline antihistamine + xylometazoline vasoconstrictor). There is no problem using these for 1 or 2 days, for example for photographs for a special occasion. However it is not recommended to use eye drops containing vasoconstrictor continuously for more than 1 week, because rebound redness of the eyes will occur when the vasoconstrictor is stopped. 

Combined mast cell stabilizer- antihistamine eye drops such as Olopatadine or Ketotifen are very effective for itch and redness due to allergy. They can be used safely all year round if necessary. These must be prescribed by a doctor.

Olopatadine can be used morning and night in contact lens wearers if prescribed by your eye specialist, before inserting and after removing contact lenses each day.

Other mast – cell stabilizing eye drops which may be prescribed by your eye specialist include nedocromil and lodoxamide.

may be required for more severe inflammation and mucus discharge. Steroid eye drops are most commonly used 1-4x/day. Steroid eye drops are associated with development of glaucoma (high intra-ocular pressure), cataracts and infection, so only using the minimum amount of corticosteroid necessary to treat the redness and improve comfort is the goal.

For chronic inflammation due to allergic eye disease, Ciclosporin eye drops may be indicated. They reduce inflammation safely, without causing the side effects associated with steroid eye drops. They have a slow onset of action and the eye drops sting during approximately the first month of use.

For puffy redness of the eyelid skin, steroid creams may be prescribed by Miss Saw. These must be used sparingly and for limited periods, because they can make the skin of the eyelids thin and can cause high intraocular pressure. Inflammation frequently returns when steroid cream is stopped.

If the eyelid skin has chronic recurrent eczema, topical anti-inflammatory cream such as pimecrolimus or tacrolimus 0.03% or 0.1%, which does not have the side effects of steroids, may be prescribed.

Oral corticosteroids or local corticosteroid injection in the eyelids may be required in some severe cases of allergic eye disease. Corticosteroids are only used for limited periods of time to rapidly control inflammation.  This is in order to minimise the side effects of long term corticosteroids (Cushing’s syndrome, infection, bone thinning, thin skin with easy bruising).

For patients with severe eye inflammation and severe skin eczema, systemic immunosuppression with ciclosporin, tacrolimus or mycophenolate may be indicated. This must only be commenced by a specialist who is expert in systemic immunosuppression, and in collaboration with the patient’s dermatologist. 

Immunotherapy (allergy shots) can help in some people. It is mainly available for hay fever sufferers, to provide long-term resistance to triggering allergens.

Perennial and Seasonal allergic conjunctivitis are not sight-threatening conditions. Like hayfever, they may be present for the rest of one’s life.

Most children grow out of vernal keratoconjunctivitis once they are in their 20s. The vernal children who continue to have active chronic allergic eye disease after the age of 20 are then called atopic keratoconjunctivitis.

Perennial and seasonal allergic conjunctivitis themselves are not sight-threatening conditions. Vernal and atopic keratoconjunctivitis are potentially sight-threatening and often require treatment with topical and/or oral steroids and immunosuppressive therapy. Both vernal and atopic keratoconjunctivitis can cause permanent scarring of the cornea, the clear front window of the eye, and damage to limbal stem cells.

Keratoconus is often associated with allergic eye disease (SAC, PAC, VKC, AKC). Avoiding eye-rubbing is thought to be important, to prevent the development or worsening of keratoconus. See “Keratoconus”.

Atopic keratoconjunctivitis is also associated with reduced immunity against Herpes simplex infection and Staph infection. Herpes simplex affecting the cornea can lead to permanent scarring of the cornea and blindness.