Allergic Eye disease

 

The prevalence of eye diseases in urban areas is increasing day by day and constitutes about 20% to 40 % in the children below 12 years.

A large number of different types of allergens are present in our environment like pollen, mould, spores, dust mites, animal dander and air pollutants from factories and vehicles. The studies conducted in different areas with different levels of air pollution has presented with very interesting revelations. The modern type 2  air pollutants like NO2 , Ozone, VOCS ( volatile organic substances), tobacco smoke, diesel emission particles, fine and ultra-fine particles were found to adsorb to airborne particles and they in turn attach to pollen surfaces and increase the release of allergenic proteins. It was found that pollens collected at the road-side which had pollutants attached to them were potentially more allergenic than those collected from rural meadows.

Environmental tobacco smoke exacerbates allergic diseases in children. Passive smoking during pregnancy or lactation was found to be a risk factor for respiratory ailments like asthma and allergic diseases in the offspring.

Allergic contact eczema

This is caused by the direct contact of the allergens to the skin of the eyelids or that around the eyes. The allergens include:-

Eye cosmetics

Contact lenses

Allergen contaminated pillow, like with hair dye of other person

Nail varnish

Drugs used for medicinal purpose like neomycin, gentamycin etc

Sun exposure (Photo contact allergy)

Preservatives in eye drops

Metals like nickel (may be contained in spectacle frames and eye lash curlers)

Rubber eyelash curlers or swimming goggles.

Plant products like grape seeds, grape fruit seeds, green tea, ginger, sunflower, wheat sage, oatmeal, ginseng, cocoa butter… and many more..

Erythematous and itching, well circumscribed macules with scales are the main presentation of this disorder.

Atopic eczema

It is the inflammatory, chronically relapsing, itching skin disease with typical age-related distribution of lesions. Most of the cases start below 5 years of age. It causes eyelid eczema and also itching of the eyes and eye lid skin and many times associated with allergic rhinitis (sneezing and running nose) and the dark discolouration around the eyes.

 

Allergic conjunctivitis

Seasonal allergic conjunctivitis

Symptoms are itching, redness, lid swelling and stringy mucoid discharge of the eyes. Mostly occurs during specific seasons especially spring or autumn.

Perennial allergic conjunctivitis

It is also associated with itching of eyes, redness, swelling of lids and stringy discharge but it occurs throughout the year but may have remissions and exacerbations. The common causative factors are dust mites and cat or animal dander that is present throughout the year.

 

Vernal conjunctivitis

It starts in children of as small as 2 to 4 years and is associated with itching and redness that is typically pink in colour. The children rub their eyes intensely and also there is increased blinking and also stringy, ropy discharge. This if left untreated can cause ulcers of the cornea called as shield ulcers. This type of allergy occurs in children mostly in spring and so it is also called as spring catarrh. It usually dis appears after teen age but treatment is necessary till that age.

Atopic kerato-conjunctivitis

It is associated with allergic asthma or allergic rhinitis (running nose and sneezing) 87% of the times. It starts in teens or early 20s and may persist for decades.  The skin of the eyelids and around is frequently involved. The symptoms in eyes include intense itching, tearing and light sensitivity (photophobia) due to corneal involvement, redness of eyes, blurred vision, and stringy discharge. If left untreated it can cause scarring of the eyelids, the openings of the lacrimal apparatus called as puncta present at the corner of the eyes which drain the tears and also the conjunctiva causing stem cell deficiency.

Prevention and Treatment: - It is very challenging to treat allergies as the allergens are very difficult to pin point in each individual and their presence cannot be completely discarded from the environment. Glares are a must while driving and protective glasses while working in polluted environment. Cleaning of eyes with regular tap water after coming home from work is also useful. Washing of hands after handling medicines or cosmetics prevents them from reaching eyes due to contact.

Allergies are treated with anti-histaminic drops, decongestant drops or steroids. Now, a large choice of medicines are available that can be prescribed according to specifications of signs and symptoms. The most important part is that when allergy is intense and chronic, steroids have to be prescribed, which can cause side effects like raised eye pressure and cataract if used for prolonged periods, but now steroid preparations which have fewer side effects, are available which are of immense help.

Also when there is conjunctival scarring due to chronic allergy, stem cell transplants are a hope to the patients.