When an inflammatory process involves the cornea, the condition is termed keratitis. An ulcer developing in the cornea is usually accompanied by keratitis, but more importantly involves a loss of the covering epithelium, many a time with the tissue underneath it as well. It is a relatively common condition as the cornea is exposed to the environment. Corneal ulcers tend to be more common in the tropical countries, especially where agriculture is in abundance, as in India. They may be a cause of great visual morbidity and economic loss to the individual.
Infective corneal ulcers are, by far, the commonest causes of ulcers in the tropics. Among these, bacterial infections are quite frequently encountered. Predisposing factors like trauma may lead to bacterial corneal ulcers, which tend to severer than other infections. Fungal infections may occur, especially, after injuries with vegetative matter like leaves or twigs. Viral corneal ulcers with the Herpes Simplex virus are very common.
Patients of corneal ulcers are very distressed and disturbed with their condition. There is a lot of pain due to exposure of naked nerve endings. Redness and watering are marked. The patient is intolerant to bright light. There may be other symptoms as well, especially if the infection is severe, like headache, malaise and fever. Symptoms are more marked in case of bacterial ulcers and quieter with fungal ulcers.
Corneal ulcers are potentially serious and even sight threatening conditions. Consultation with an ophthalmologist should never be delayed if the above symptoms are present. Some, very superficial ulcers may heal fast without any sequelae. But many are associated with complications. Infection may spread leading to corneal thinning and perforation. It may spread to the interior of the eye leading to endophthalmitis. Scarring may occur in the cornea, as occurs in other parts of the body. This scar tissue tends to be opaque compared to the normal cornea, thereby, obstructing light and causing blurred or diminished vision.
After a proper examination under a slit-lamp and other tests that may sometimes be necessary, the type of infection is recognized and a line of therapy selected. Bacterial ulcers are treated with topical fortified antibiotic preparations. These are not available commercially and have to be prepared from injectable forms of the same antibiotics. Fungal ulcers require anti-fungal eye drops. Herpetic ulcers are treated with topical anti-virals like acyclovir. Supportive therapy for the dilatation of the pupil and relaxation of the ciliary muscle is usually added. Oral medication in the form of pain-killers or anti-fungals may be required.
Occasionally required modalities that may be added include bandage contact lenses, conjunctival flaps, scraping of the ulcer, etc. A corneal transplant may be essential if the ulcer has healed leaving a large scar that obstructs vision.
It is important for patients to realize that steroids and anesthetic drops should be avoided in case of corneal ulcers. They delay healing and may actually make the condition worse. They should only be used after consultation with an ophthalmologist.