A corneal ulcer (keratitis) is an erosion or an open sore on the cornea which is the thin clear structure of the eye that refracts light. If the cornea becomes inflamed due to infection or injury, an ulcer may develop.
The causes of a corneal ulcer (keratitis) are:
Multiple organisms are responsible for development of a corneal ulcer (keratitis).
The types of corneal ulcer (keratitis) are –
The ulcer is carefully examined on the slit lamp microscopy for the analysis of size, shape, margins, sensation, depth, inflammatory reaction, hypopyon and presence of any foreign body. A fluorescein dye is used to stain the ulcera to enhance the features and check for any leak.
Debridement of the ulcer is essential for microbiological evaluation to identify the causative organism. After putting an anaesthetic drop in the eye, the margins and the base of the ulcer is scraped with the help of a sterile disposable blade or needle. These samples are stained and cultured to identify and isolate the organism. Scraping the ulcer also helps in better absorption of the eyedrops.
If the patient is a contact lenses wearer, the lenses will be sent for microbiological evaluation. Random blood sugar levels are to be checked. If the sugars are not in control, a diabetologist opinion is taken as this affects corneal wound healing. A gentle ultrasonography of the affected eye is done to check for any posterior segment pathology.
Depending on the laboratory reports, treatment will be started. Antibiotics, antifungals or antivirals are started in the form of tablets and eye drops depending on the causative agent. In cases of large or severe corneal ulcer (keratitis), fortified eye drops are started which are prepared from available injectable preparations. This is accompanied by oral pain killers, cycloplegics eye drops which relieves pain, anti glaucoma eye drops to reduce the intraocular pressure and artificial tears. The frequency depends on the size of the ulcer. Corticosteroids are strictly prohibited in cases of fungal corneal ulcer (keratitis). However, they can be considered in other types of ulcers at a later stage under extreme caution and supervision.
In case of a small perforation, tissue adhesive glue is applied over the perforation under sterile conditions followed by a bandage contact lens to seal the perforation. Bandage contact lenses are also used in cases of recurrent epithelial erosions for better healing. Patients who have eyelid deformities, leading to an ulcer, need corrective surgeries. If the corneal ulcer (keratitis) is due to an eyelash growing inward, the offending lash should be removed together with its root. If it grows back in an abnormal manner, the root may have to be destroyed using a low-voltage electrical current. In cases of improper or an incomplete lid closure, a surgical fusion of the upper lid and lower lid is done. Small perforations are also treated with patch grafts which means taking a full thickness or partial thickness graft from the donor cornea and anchoring it over the perforated site.
For non healing ulcers surgical intervention is required. An amniotic membrane graft is placed on the cornea under sterile conditions to build thickness and establish healing. However, in cases of larger perforation or severe scarring, corneal transplant surgery is done which involves surgical removal of the diseased corneal tissue and replacing it with a healthy donor tissue.
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Written by: Dr. Preethi Naveen – Training Committee Chair – Dr. Agarwals Clinical Board
The prognosis for a corneal ulcer (keratitis) depends on its cause, its size and location, and how rapidly it is treated together with the response to treatment. Depending on the degree of scarring, patients might have visual disturbances. If the ulcer is deep, dense, and central, scarring will cause some permanent changes in vision.
Depending on the cause of the ulcer and its size, location, and depth corneal ulcer (keratitis), it can take from 2 weeks to 2 months to heal.