Corneal Ulcer

The cornea is the clear, dome-shaped window at the very front of your eye. It lets light in and helps focus it. A corneal ulcer is an open sore on the cornea. Most are caused by an infection, which doctors call infective (microbial) keratitis (keratitis means inflammation of the cornea).

Germs that can cause a corneal ulcer include [1][4][5]:

• Bacteria: the most common cause. Some bacteria can damage the cornea within a day or two.
• Fungi: often after the eye is scratched by plant material, such as a branch, leaf, thorn or crop. This is more common in farming, gardening and rural areas and in hot, humid tropical countries like ours.
• Acanthamoeba: a tiny organism found in tap water, pools, the sea, soil and dust. It mostly affects contact lens wearers and can be very hard to treat.
• Viruses: especially the herpes simplex (cold sore) virus, which can come back again and again.

Image to add

Close-up drawing of an eye with a white spot on the clear cornea and a red eye around it. Alt text: "Drawing of an infected eye with a white patch on the cornea, which is a corneal ulcer, and redness of the white of the eye."

What causes it?

The cornea is normally very good at keeping germs out. An ulcer happens when its surface is damaged (by a scratch, a contact lens or dryness), allowing germs to get in and grow. Contact lenses can trap germs against the eye and reduce the oxygen the cornea gets.

Your risk is higher if you [1][2]:

• wear contact lenses, which is the biggest risk, especially if you:
  • sleep in them (including naps)
  • swim, shower or wash your face with them in
  • rinse lenses or the case with tap water, or top up old solution
  • wear them longer than advised, or do not replace the case
• have an eye injury, especially from plants, soil or wood
• have dry eyes, or eyelids that do not close fully
• use steroid eye drops, especially without a doctor checking your eye
• have had a cold sore virus infection in the eye before
• have diabetes or a weak immune system
• have had eye surgery on the cornea

Signs of a corneal ulcer usually come on over hours to a few days, and usually affect one eye:

• Eye pain, often bad, or a feeling that something is stuck in the eye
• A red eye
• Blurred vision
• Sensitivity to light
• Watering or discharge (pus)
• A white or grey spot on the clear part of the eye, which you may see in the mirror

At the clinic, the doctor will look at your eye with a microscope (slit lamp) and use a yellow dye (fluorescein) to show the ulcer. They will often take a scraping from the ulcer for tests (culture), to find out exactly which germ is causing it [1].

What can happen?

A corneal ulcer can get worse within hours. Without quick treatment it can cause [1]:

• a permanent scar on the cornea, leaving vision blurred for life
• the cornea becoming thin, and in severe cases a hole in the eye (perforation)
• infection spreading inside the eye
• permanent loss of vision, or even loss of the eye
• the need for a corneal transplant (replacing the cornea with a donor cornea)

A corneal ulcer is an eye emergency. It is not something to "wait and see".

Treatment must start quickly and is usually given by an eye specialist [1].

1. Antibiotic eye drops: strong drops are used very often, sometimes every hour, day and night, for the first day or two. Some people need to stay in hospital to manage this.
2. Other drops for other germs: antifungal drops for fungal ulcers [7], special drops for Acanthamoeba, and antiviral medicine for herpes.
3. Drops to ease pain, which relax the eye muscles.
4. Steroid drops are used only in some cases, and only by an eye specialist once the right germ is being treated [6].
5. Surgery: if the cornea becomes very thin or gets a hole, or leaves a bad scar, a corneal transplant or other operation may be needed.

You will need frequent check-ups, sometimes daily at first. Do not stop the drops early, even if your eye feels better.

Important: do not treat it yourself. Do not use leftover, borrowed or shop-bought drops. Steroid drops can make an infection much worse. Do not use traditional remedies, breast milk or herbal water in the eye.

If you wear contact lenses [2][3]:

• Do not sleep in your lenses, unless your eye doctor says it is safe.
• Take them out before swimming, showering or using a hot tub.
• Never use tap water or saliva to clean or store lenses.
• Use fresh solution every time. Do not top up old solution.
• Wash and dry your hands before touching your lenses.
• Replace your lenses and lens case as advised (the case at least every 3 months).
• Keep a pair of glasses as a backup, and take your lenses out if your eye becomes red or sore.

For everyone:

• Wear eye protection when gardening, farming, cutting grass or using tools.
• Treat dry eyes if you have them.
• Only use steroid eye drops when prescribed by a doctor who is checking your eye.

Where to get help in Brunei

For a painful red eye, especially if you wear contact lenses, go to a Community Eye Clinic at your health centre the same day. No referral is needed.

After clinic hours, or if your vision is getting worse quickly, go to the hospital Emergency Department.