The conjunctiva is the membrane that lines the front of the eyeball, continuing until the inner surface of the eyelids.

The conjunctiva is the membrane that lines the front of the eyeball, continuing until the inner surface of the eyelids. Inflammation of the conjunctiva is called conjunctivitis and can be due either to infectious or non-infectious cause.

Infectious conjunctivitis

It can be caused by bacteria, viruses or chlamydia.

The microbial conjuctivitis is characterized by acute onset of redness of the eye and sticky secretions (eye gum). Light or moderate itching and sense of burning or foreign body may co-exist The vision, to a great extent, is not affected. Significant reduction in vision may conceal other serious cause, or corneal involvement.

Most cases of microbial conjunctivitis are self-limiting, but usually the doctor prescribes eyedrops with broad-spectrum antibiotic, such as tobramycin, fusidic acid or chloramphenicol.

Infection of the conjunctiva by gonococcal (the microbe that causes the venereal disease gonorrhea) is an acute and very serious situation, because the gonococcus can penetrate even the intact (without injury) corneal epithelium causing significant damage if not treated with special antibiotic treatment.

The virus conjunctivitis case has certain characteristics which distinguish this type of disease from microbial type. The redness of the eye is still a symptom, but the secretions are more watery (thin) than purulent. Frequently swelling of the preauricular lymph nodes is observed, as well as swelling of the eyelids, which is sometimes so intense that it causes convergence of the eyelids

This type occurs frequently in the course of viral infections during childhood and need special care because of their high transmissivity. Particular care should be taken to frequent handwashing, non-use of common towels, pillows, etc.

As in most infections, viral conjunctivitis shall run its course without any special treatment. Cases of virus herpes conjunctivitis (usually accompanied by a blistering rash on the eyelids), are an exception, since they require use of specific antiviral agents.

Regarding chlamydial conjunctivitis trachoma is the most common cause of blindness worldwide following cataract and glaucoma. It is referred to a chronic conjunctivitis, usually affecting countries with poor sanitation. The treatment is done with the appropriate antibiotics.

Noninfectious conjunctivitis

This category includes acute and chronic allergic conjunctivitis and some scarring and vesicular lesions of the conjunctiva.

Allergy is called the over-reaction of some seemingly "harmless" substance of the environment. The most common allergens are pollen, mold, animal saliva, various chemicals, and certain foods and drugs.

The cute allergic conjunctivitis is characterized by sudden onset with itching, swelling of the eyelids and chemosis (edema) of the conjunctiva. The allergic reaction entails prior contact with the respective allergen. So, the patient must be aware of the substances affecting him, so that he may avoid them, while the use of eyedrops, artificial tears and water washes are necessary in order to remove the allergen, if the patient has already been exposed to that.

Both for the prevention and for the relief of acute allergic conjunctivitis there are several eyedrops (vasoconstrictors, antihistamines, etc.) available.

The chronic allergic conjunctivitis has various forms, such as vernal and atopic keratoconjunctivitis.

Vernal allergic keratoconjunctivitis most often affects children, usually boys. It is more intensive in dry and warm climates, especially during summer months. Symptoms are affecting both eyes and include severe itching, redness, burning, sense of foreign body, tearing, thick filamentous secretions and photophobia.

Patients with vernal allergic conjunctivitis generally have positive personal and family history of seasonal allergies, atopic dermatitis and asthma. After a few years of active disease, the majority of patients presents automatic cure.

Atopic form usually affects older people with positive personal and family history of skin atopy or asthma. This is a potentially serious disease that can lead to blindness. A large number of ophthalmic conditions coexist with atopic allergic conjunctivitis. These are keratitis due to simple herpe, the anterior and posterior subcapsular cataract and keratoconus.

The treatment of chronic allergic conjunctivitis is similar to that of seasonal allergic, although topical steroids are used more in this case.