Keratitis (inflammation of the cornea)

Introduction

The cornea of the eye is the front part of the eye and constitutes a significant part of the eye's optical power. The cornea contains no blood vessels and is completely transparent. The cornea is nourished by components from the tears and from the nerve endings that innervate it. Accordingly, any damage to the components of the cornea or to its function may cause various vision problems and sometimes blindness. Inflammation of the cornea is related both to external factors such as viruses and to internal (endogenous) factors such as systemic diseases and various autoimmune diseases. Keratitis is especially common in people who wear contact lenses. But people who do not tend to wear contact lenses can also, as noted, suffer from inflammation or infection of the cornea.

Symptoms

Inflammation of the cornea usually manifests as redness and pain in the eye that worsen on exposure to light. However, if there is a corneal ulcer, one may also see copious discharge, tearing and even opacity of the cornea.

Causes

There are various causes of keratitis and inflammation of the cornea. Among them can be found pathogens such as bacteria, viruses or fungi, which often cause inflammation. In addition, irritations or other traumas may also cause keratitis.

• Infection of the cornea and bacterial inflammation of the cornea often affects older people or people suffering from another disease such as diabetes, cancer, various autoimmune diseases or immune deficiency from other causes.
• The common viruses that cause keratitis are Herpes, VZV or Adenovirus. These viruses damage the cornea in various ways. For example, herpes can, in recurrent attacks, infect various parts of the eye surface and cause inflammation and scarring of the cornea.
• Damage to the cornea by fungi is associated with fungi of the Candida and Aspergillus types and others. These fungi may cause a corneal ulcer that can lead to significant damage to the eye and considerable impairment of vision.

As noted, the use of contact lenses is clearly related to inflammation of the cornea, since it may increase exposure to infections for many reasons. For example, damage to the corneal cells during insertion and removal of the lenses increases the chance of pathogens penetrating the eye and harming it. In addition, sleeping with contact lenses increases the risk of inflammation of the cornea through disruption of the tear mechanism that nourishes the cornea. Moreover, prolonged use of contact lenses acts as a barrier to the passage of oxygen to the cornea, so that blood vessels develop in it and weaken it.

Accordingly, inflammation of the cornea that does not stem from an infectious source is also possible. Among other things, dry eyes, foreign bodies, UV radiation or various allergens can cause keratitis. It should be noted that inflammation of the cornea that is not caused as a result of infection is not contagious.

Diagnosis

Inflammation of the cornea is diagnosed by a specialist ophthalmologist. The diagnosis is based on several components, including identifying the symptoms the patient suffers from, a clinical examination of the eye and, if possible, also taking a sample of the discharge that will help diagnose the source of the infection.

Treatment

Keratitis is usually caused by an infection of the cornea from a bacterial source, so treatment is usually based on instilling eye drops containing antibiotics of various types. In cases where the inflammation is caused by herpes, it should be treated with appropriate ointments. It should be noted that systemic treatments in pills are not suitable for most inflammations of the cornea since, as recalled, the cornea is not connected to a broad blood-vessel system. If the treatment is carried out well, a relatively rapid improvement in symptoms can be seen until full healing of the corneal inflammation after about two weeks. In cases of more severe forms, the healing process will take longer.

However, when it comes to an ulcer that occurred during the inflammation of the cornea, there is a significant threat to the function of the eye and to the ability to see. This is an emergency that requires immediate medical treatment in order to prevent severe consequences. In many cases of a corneal ulcer, hospitalization in a hospital is required. In situations where the damage to the cornea is vision impairment or scarring, a corneal transplant by surgery should be considered. Such a procedure has high success rates compared to other transplant surgeries and low chances of graft rejection.

Summary

From the above, the source of keratitis and inflammation of the cornea can be a viral, bacterial, fungal or autoimmune infection. The risk factors for the development of inflammation of the cornea are wearing contact lenses, dry eye, accompanying diseases, penetration of foreign bodies into the eye and more. The period of time between the appearance of the symptoms and their diagnosis and the start of treatment is of crucial importance for visual function – this is because the deeper the injury, the greater the chance of significant damage to vision.