Corneal Ulcers
Corneal ulcers are open sores or epithelial defects with an underlying inflammation on the cornea.
A Cornea ulcer will often appear as a grey to white opaque or translucent area on the normally clear and transparent cornea. Some corneal ulcers may be too small to see without adequate magnification.
Cornea is the structure in front of the eye. The cornea overlies the iris which is the coloured part of the eye and is separated from the iris by the aqueous fluid in the anterior chamber of the eye.
Causes of Corneal Ulcers
Most Corneal ulcers are caused by infection these include:
- Bacterial infections:
Staphylococcal cause corneal ulcers and are common in contact lens wearers- Bacteria can directly invade the cornea if the surface has been disrupted because some bacteria produce toxins that can cause ulceration of the cornea,
- Viruses:
Those viruses that can cause corneal ulcer include the herpes simplex (virus that cause cold sores), Varicella virus ( those virus that cause chicken pox and shingles).
- Fungal infections:
These can cause corneal ulcer and may occur with improper care of contact lenses or over use of eye drops that contain steroids.
- Tiny cuts or scratches:
on the corneal surface may become infected and lead to corneal ulcer (e.g metal wood,glass or almost any type of particle that strikes the cornea can cause minor injury,) Such injuries can damage the corneal surface and make it easier for bacteria to invade and cause corneal ulcer.
A corneal abrasion is a larger loss of the corneal surface and may ulcerate if left untreated.
- Disorders that cause dry eyes (keratitis sicca)
can leave the eye without the germ fighting protection of the tear film and cause or aggravate corneal ulcer.
- Disorders that affect the eyelid
These prevent the eye from closing completely such as Bell’s Palsy can dry the cornea and make it more vulnerable to ulcer.
- Mechanical factors of the eye lid
turning inward towards the eye or lashes growing inward and rubbing against the cornea can cause corneal ulcer.
- Chemical burns
or other caustic/ damaging solutions splashing into the eye can injure the cornea and lead to corneal ulceration.
NOTE:
- A corneal ulcer is an open sore on the cornea.
- There are a wide variety of causes of corneal ulcer including infection physical and chemical trauma corneal drying and exposure and contact lens wear/ misuse.
- Corneal ulcer are serious problems and may result in loss of vision or blindness.
- Most corneal ulcers are preventable
- With appropriate timely treatment, the majority of corneal ulcer will improve with minimal adverse effect on vision.
- Any condition which causes loss of sensation of the corneal surface may increase the risk of corneal ulceration.
- Immunological disorders( immune suppressed, rheumatoid arthritis, lupus and others) may develop corneal ulcers as a complication of their disease. Patients with immune mediated scleritis can also develop corneal ulcer.
Signs and Symptoms
- Redness in the conjunctiva of the eye and in the anterior chamber of the eye. ( Redness is due to dilatation of the conjunctival blood vessels.
- Eyelids may be swollen and a white or grey round spot on the cornea could be visible with the naked eye if the ulcer is large.
- There may be swelling (edema) around the ulcer.
- Disturbance in vision.
- There may be scarring from prior corneal ulcers, there may be single or multiple ulcers in the eye and the ulcer may be present in one or both eyes.
- There may be pain which may increase when the person looks at bright light ( photophobia)
- A feeling of foreign body in the eye.
- Tearing, pus or thick discharge draining from the eye may occur, if the ulcer is more centrally located in the cornea vision may be blurry.
Investigations
- The doctor will use a slit lamp (special microscope to detect the ulcer), the florescent dye drop will be used to assist him see it better.
- Pus swab may be taken for microscopy
Culture/Sensitivity.
Management of Corneal Ulcers
The treatment is aimed at eradicating the cause of the ulcer. Using a slit lamp ( in certain situations steroids may hinder healing or aggravate infection.
- Anti-Infective agents directed at the inciting microbial agent will be used in cases of corneal ulcer caused by infections.
- These will be in form of Ointments/ Drops to be put/instilled in the eyes.
- In case of Viral infections Oral medications will also be employed.
- Sub conjunctival injection of antibiotics may sometimes also be used.
- Steroids may occasionally be added but only after examination of the eye by an eye Doctor or other Physician.
Surgical Management
- If the corneal ulcer is due to an eyelash growing inward, the offending lash should be removed together with it’s root. If it grows back in an abnormal manner the root may have to be destroyed using a low voltage electrical current.
- Scrapings of the ulcer also may be sent to the laboratory to identify out bacteria, fungi or viruses. Certain bacteria such as a species of Pseudomonas may cause corneal ulcer which is rapidly progressive
- If the corneal ulcer is due to eyelid turning inward Surgery directed at correctly repositioning the eyelid may be necessary
- Contact lenses should be discontinued in the affected eye of any case of corneal ulcer regardless of whether the ulcer was initially caused by the contact lens.
- If the ulcer cannot be controlled with medications, it may be necessary to surgically debride the ulcer. If the ulcer causes significant corneal thinning and threatens to perforate the cornea, a surgical procedure known as corneal transplant ( keratoplasty) may be necessary.
Preventive Measures
- Individuals should wear eye protective gears when using power tools or when they may be exposed to small particles that can enter the eye ( like particles from grinding wheel or a weed whacker)
- Individuals who have dry eyes or whose lids do not close properly should use artificial teardrops to lubricate the eyes and keep them lubricated.
- If an eye is red and irritated and worsens or does not respond to OTC ( Over the counter) eyedrops within a day contact an Ophthalmologist promptly.
- People wearing contact lenses should be very careful about the way they clean and wear those lenses.
- Always wash hands before handling those lenses.
- Never use saliva to lubricate contact lenses because the mouth contains bacteria that can harm the cornea.
- Remove lenses from the eyes every evening and clean them.
- Never use tap water to clean the lenses
- Never sleep with contact lenses not designed for overnight wear in the eyes.
- Store lenses in disinfecting solutions overnight.
- Remove lenses whenever the eyes are irritated and leave them out until there is no longer any irritation or redness.
- Regularly clean the contact lens case, carefully read the instructions about contact lens care supplied by the lens maker, consider using daily disposable lenses.
Complications
- Cloudy scar that impairs vision.
- Infections
- Perforation of the cornea.
- Displacement of the Iris
- Destruction of most or all of the tissue in the eye socket
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