What is Corneal Ulcer (Keratitis)?

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.

Symptoms of Corneal Ulcer (Keratitis)

• Redness
• Pain
• Watering
• Gritty sensation
• Blurry vision
• Discharge
• Burning
• Itching
• Light sensitivity

Causes of Corneal Ulcer (Keratitis)

• Contact lenses – contaminated solution, poor hygiene, over usage, sleeping with contact lenses on, using tap water or swimming with contact lens on. Wearing lenses for extended periods blocks the supply of oxygen to the cornea, making it susceptible to infections.
• Trauma – chemical injury, thermal burn, bee sting, animal tail, makeup or vegetative matter like the branch of a tree, sugarcane
• Post-surgery – delayed healing, loose sutures
• Lid deformities – inward or outward turning of eyelid, misdirection of eyelashes constantly rubbing over the cornea, incomplete closure of eyes
• Decreased nerve supply to the cornea – seen in diabetics and bell’s palsy patients
• Allergic conjunctivitis
• Vitamin A deficiency
• Prolonged use of eye drops – corticosteroids
• Severe dry eyes – caused by medical conditions like diabetes mellitus, thyroid disorder, vitamin A deficiency, rheumatoid arthritis, Sjogren syndrome, Stevens-Johnson syndrome

Risk factors of corneal ulcer (keratitis)

• Injury or chemical burns
• Eyelid disorders that prevent proper functioning of the eyelid
• Dry eyes
• Contact lens wearers
• people who have or have had cold sores, chicken pox or shingles
• Abuse of steroid eye drops
• Diabetics

Corneal Ulcer (Keratitis) Prevention

• Do not sleep with contact lenses on
• Do not overuse contact lenses
• Wash your hands before putting the lenses
• Advised to use daily disposable lenses
• Do not use tap water as lens solution
• While riding a bike, wear eye protection or visor to prevent foreign bodies from entering the eye.
• Do not rub your eye
• Proper instillation of eyedrops. The nozzle of the eye drop bottle should not touch the eye or the finger
• Use artificial tears in case of dry eyes
• Wear protective eyewear when working with wood or metals, especially when using a grinding wheel, hammering on metal, or welding.
• Do not use over-the-counter eye drops

Types of corneal ulcer (keratitis)

Multiple organisms are responsible for development of a corneal ulcer (keratitis).

The types of corneal ulcer (keratitis) are –

• Bacterial – scratches or abrasion with fingernail, paper cuts, makeup brushes over the cornea when left untreated can lead to an ulcer. common in extended wear contact lens wearers
• Fungal – injury to the cornea with any vegetative matter or improper use of steroid eye drops
• Viral – the virus that causes chickenpox and shingles can cause ulcers too
• Parasitic – infection caused by fresh water, soil or long standing contact lens used

Corneal ulcer (keratitis) Diagnosis 

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.