Corneal abscess – Corneal infection
A corneal abscess is a serious eye emergency . It is a severe and potentially blinding infection. You should suspect it if your eye is red and painful, especially if you have been wearing contact lenses . If a white spot appears in the center of the eye, on the cornea, there is no doubt. It is crucial to stop wearing your lenses immediately, even if they provide relief. Seek emergency medical attention to confirm the diagnosis and begin antibiotic treatment. In severe cases, a biopsy and hospitalization may be necessary. After recovery, the ophthalmologist will decide whether or not you can wear contact lenses again.
What is a corneal abscess?
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A corneal abscess is an infection of the first transparent layer of the eye: the cornea.
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A germ: most often a bacterium, sometimes a virus, a fungus or an amoeba infiltrates the layers of the cornea.
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It becomes infected, inflamed and loses its transparency, leading to redness, pain, photophobia and a white spot in front of the pupil.
Who is affected? Risk factors
Patients at risk of developing a corneal abscess include:
Contact lens wearers.
People who have recently suffered trauma or a burn to the cornea.
Patients on long-term corticosteroid eye drops.
Patients with a history of herpetic keratitis or ophthalmic shingles.
In cases of severe dry eye.
In case of eyelid abnormalities: lagophthalmos (eyelid that does not close), ectropion, entropion (eyelid that retracts or droops).
The symptoms
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Pain – The first thing that strikes you is often pain, very intense pain.
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Photophobia – You also find that you have a poor tolerance for light.
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Watery eyes – Your eye is watering uncontrollably.
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Blurred vision – As a rule, you also experience difficulty seeing. The decrease in vision may be slight or severe.
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Redness – It is inconsistent in the early stages. The eye is red with a rim around the iris: the pericorneal circle.
The perikeratic circle
The eye is red. The blood vessels in the white part of the eye (the sclera) are dilated and form a circle around the central part of the eye (the iris and the pupil): the pericorneal circle.
Sometimes you can even distinguish the corneal abscess directly as a white spot.
Diagnosis
Diagnosing a corneal abscess is straightforward. It is performed by an ophthalmologist using a slit lamp. To facilitate the examination, a drop of anesthetic (Oxybuprocaine®) may be instilled.
In practice, the doctor will notice a red eye and a white spot on the cornea. A drop of dye (fluorescein) can help analyze the abscess. The ophthalmologist will then look for signs of severity that may warrant a biopsy and sometimes hospitalization.
Severity criteria
The criteria for the severity of a corneal abscess are:
The size (> 3 mm)
Proximity to the visual axis (< 2 mm from the center)
Intraocular inflammation – Inflammatory cells develop in the eye.
In addition to this, there are criteria for a poor prognosis: corneal transplant, immunosuppressive treatment, inability to administer treatments alone,…
Causes
The most frequent cause – Misuse of contact lenses
Wearing contact lenses is the main cause of corneal abscesses.
An abscess occurs when basic hygiene rules that all soft contact lens wearers should follow have not been observed. (See below for a reminder of best practices when wearing contact lenses).
Lenses promote microtrauma to the cornea and concentrate infectious agents, leading to a risk of corneal infection when the hygiene conditions essential for their regular wear are not met.
The trap – The “bandage effect” of contact lenses
The pain is usually very intense, and wearing contact lenses may provide relief. This is known as the "bandage effect" of the lens.
By creating an interface between the eyelid and the cornea, the lens reduces the discomfort caused by blinking on the infected surface, a dangerous trap since the lens is usually the cause of the infection and must be removed!
They are a more secondary, but very real, cause of corneal abscesses. Sand, liquid splashes, abrasions, scratches, or even metallic foreign bodies can cause an abscess.
However, this is less common, as the eye is protected by the eyelids, which close reflexively in case of danger. In the event of a splash, it is important to consult your ophthalmologist immediately so they can assess the need for a preventative antibiotic to reduce the risk of abscess formation.
In some people, chronic eyelid irritation (blepharitis, most often linked to rosacea) or severe dry eye can lead to corneal irritation and cause corneal abscesses in the long term.
Corneal abscesses can be caused by all types of germs, and sometimes several at the same time. In order of frequency, they are:
The bacteria – primarily Staphylococci and Streptococci.
Viruses – Herpesvirus (HSV), varicella (VZV) and smallpox
Fungi – Filamentous or yeasts
Amoebas – Brought in by lenses that have been in contact with tap water, amoebas cause aggressive and painful abscesses because they infiltrate the nerves of the cornea.
Why consult a doctor?
A corneal abscess is a serious ophthalmological emergency that requires prompt treatment by an ophthalmologist.
Samples can be taken and antibiotic therapy via eye drops prescribed as early as possible to avoid any lasting effects.
The severity of the lesion will depend on its location. If it is located at the periphery of the cornea, it can quickly spread to the center and cause visual impairment. The larger the lesion, the more difficult healing becomes.
If the lesion is relatively superficial, there is a risk that it will deepen and lead to a corneal perforation. Even after healing, the injury may leave a scar forming a whitish film, threatening vision.
During the procedure, the doctor will examine the cornea under a microscope to confirm the presence of a lesion. They may also take a sample to test for any potential infectious agent.
A corneal abscess is an emergency and can lead to hospitalization in the most advanced cases, which is why consultation with an ophthalmologist is essential and must be done quickly.
To avoid the occurrence of a corneal abscess, the consequences of which can lead to blindness, the following conditions should always be observed if you use soft contact lenses.
The greatest enemy of the contact lens wearer is the "amoeba" which causes the dreaded amoebic keratitis, a parasite found in water, so it is essential to be wary of water when wearing and handling contact lenses!
Wash your hands thoroughly with soap and dry them before handling the lenses.
If you experience pain and/or redness of the eye, remove the lens immediately.
If the pain persists, consult a doctor at the center.
Bring your lens in the box if possible.
While in port, avoid all contact with water: no swimming, no pool, no showering.
Daily wear should be limited to about ten hours and not exceed 5 to 6 days per week.
Never sleep with your contact lenses in.
Course of action
Even though treatment can almost always be done on an outpatient basis, a corneal abscess is a serious condition!
In most cases, the infection will be treated with antibiotic drops.
Example: Ciloxan + Tobrex eye drops: 1 drop every hour for 48 hours, then 8 times a day for 5 days, then 4 times a day for 7 days.
Sometimes these eye drops will need to be obtained from a hospital pharmacy; these are hospital preparations known as "reinforced" preparations, specially designed for these infections.
In the most severe cases, the drops will be administered every hour, including at night, for 48 hours. Daily monitoring will be necessary until improvement is seen.
In the case of a serious abscess, samples will be taken. The results may take a long time to obtain and are not always helpful.
They will be especially useful in cases of infections that are refractory to the treatment initiated initially, and will be useful in determining the best treatment to overcome the most resistant germs.
Proper contact lens care is very important to prevent recurrence or the occurrence of corneal abscesses.
This involves changing daily lenses and regularly rinsing monthly lenses with a suitable solution (tap water is absolutely not one).
Dry eyes are a risk factor and can worsen corneal abscesses. Therefore, it is important to avoid air conditioning, sunlight, wind, tobacco smoke, and prolonged screen time.
Artificial tears may be the solution to alleviate this dry eye. In cases of debilitating blepharitis, your ophthalmologist may prescribe treatment.
Frequently Asked Questions
The main causes of corneal abscesses are contact lenses (and their misuse) and untreated trauma. The primary pathogens are bacteria: staphylococci and streptococci.
No! It's absolutely contraindicated. Go get a cheap, makeshift pair of glasses while it heals.
Yes! However, you must wait for the abscess to heal completely and the ocular surface to recover properly. A return to daily contact lenses is preferable. If that's not possible, get a new set of lenses, a new case, and a new bottle. Start with short wearing times: 2 to 3 hours, then gradually increase the duration.
There are no precise rules. However, a guideline of 1 month for a non-serious abscess and 3 months for a serious abscess seems advisable.
Is it possible to have refractive surgery (myopia, hyperopia, astigmatism) after a corneal abscess?
Yes! But only if the scar is small and doesn't obstruct vision. The PRK technique will be preferred. A period of 4 to 6 months between the abscess and the operation is recommended.