Keratitis and corneal ulcers
Keratitis and ulcers are corneal diseases characterized by redness, eye pain, and decreased vision. They have a wide variety of causes: traumatic, inflammatory, infectious, etc. It is important to identify the cause in order to implement the most appropriate treatment. Keratitis is, in fact, an ulceration (or erosion) of the corneal surface (epithelium). These ulcers are particularly painful due to the highly innervated structure. A corneal abscess is an infectious form of keratitis often associated with contact lens wear and is discussed in a separate article.
What are keratitis and corneal ulcers?
Keratitis and corneal ulcer are two entities referring to an erosion of the cornea.
They are distinguished by their shape and depth:
The keratitis is superficial, meaning it is no deeper than the epithelium, the first layer of the cornea. It is usually linear (a line).
The ulcer is wider and often deeper, it burrows deeper than the epithelium and reaches the stroma (fleshy layer of the cornea).
Their origins and causes are often the same.
Symptoms
Keratitis is most often unilateral, but can also affect both eyes in some cases.
They are marked by pain, photophobia (discomfort in the light) and most often a decrease in vision, more or less marked depending on the causes.
The redness of the eyes, when very significant, forms an intense red pericorneal circle (around the cornea).
The pain can cause insomnia, only relieved by closing the eye.
Why consult a doctor?
The diagnosis of keratitis will be made by the ophthalmologist after a slit-lamp examination of your eye.
The ulceration will be marked by fluorescein uptake, which indicates a break in the integrity of the corneal epithelium (surface of the cornea).
The consultation is essential since the treatment will depend on the cause (and there are many).
Without treatment, some keratitis cases can progress very unfavorably.
The causes
Infectious keratitis
Keratitis is primarily caused by infectious factors. It can be caused by bacteria. This condition is often observed in contact lens wearers and is known as a "corneal abscess".
The most frequent infectious keratitis, excluding abscesses, are:
Herpetic keratitis – Herpes can cause numerous ocular manifestations, the most common being keratitis. These can be accompanied by vesicular skin eruptions and uveitis (herpetic keratouveitis). An article dedicated to ophthalmic herpetic involvement is available here.
Adenovirus keratoconjunctivitis – In some infectious conjunctivitis cases, the cornea can be affected. This is known as keratoconjunctivitis, most often caused by a specific virus: adenovirus. Initial treatment will be with lubricating eye drops alone, followed by corticosteroids.
Traumatic/mechanical keratitis
They constitute a very significant proportion of keratitis cases. Any contact with the corneal epithelium (the outermost exposed layer of the cornea) will result in severe pain and a risk of infection. Here are the main causes:
Fingernail injuries and corneal ulcers – Fingernail injuries, often unintentionally inflicted by young children, can cause a very painful superficial keratitis known as a "corneal ulcer." This corresponds to a superficial ulceration of the eye. Any superficial trauma (from plants while gardening, for example) can induce the same condition. These episodes, while very bothersome, are fortunately benign with appropriate treatment.
Foreign bodies – Any glare directed towards the eye can project foreign bodies. The most common is iron filings from the use of an angle grinder or chainsaw, for example. Those in the construction industry are more exposed to this. Only an ophthalmologist is qualified to remove them safely.
Welder's arc eye – Welding without protection exposes the wearer to arc eye, a very painful burn to the corneal epithelium. This condition is similar to snow keratitis, which is caused by not wearing protective eyewear during strong UV exposure.
Splashes and burns – The most serious eye burns are caused by alkalis, not acids. Alkalinities penetrate deep into the cornea.
Exposure keratitis
Trichiasis – Trichiasis are eyelashes with an abnormal implantation. They point inward, rubbing against the cornea and causing irritation. They can be observed in several conditions such as entropion (inward turning of the eyelid) or inflammatory thickenings. These eyelashes will be removed mechanically or with an Argon laser at a later stage to prevent regrowth.
Entropion and ectropion – Malpositions of the eyelid lead to repeated rubbing of the eyelashes or a lack of proper eyelid closure.
Blepharitis – Chronic eyelid irritation, known as blepharitis, is most often linked to rosacea. It can cause significant keratitis.
Dry eye syndrome – Dry eye syndrome is a very common cause of keratitis. It is a superficial punctate keratitis, which can be very significant in certain disorders, particularly Sjögren's syndrome. It is treated with lubricating eye drops.
Inflammatory keratitis
Some cases of keratitis are linked to autoimmune diseases. An etiological workup (blood tests, X-rays, etc.) will be offered, and anti-inflammatory treatment will be administered.
Toxic keratitis
The misuse of certain eye drops can cause toxic keratitis. Sometimes, this involves eye drops used correctly (for example, in cases of glaucoma).
A discussion with the ophthalmologist is necessary to define the best strategy.
Recurrent keratalgia is a distinct clinical entity characterized by frequent episodes of very painful keratitis. The causes are quite numerous. Two in particular are more common:
Corneal dystrophies – Corneal dystrophies (hereditary corneal abnormalities) such as Cogan's dystrophy can be a source of recurrent keratalgia.
Secondary dystrophies – It often happens that a direct trauma, such as a nail injury or a gardening accident, induces a lesion of the corneal epithelium which tends to “crack” frequently, causing relapses, which are the cause of painful episodes.
These two causes (and all others) will receive the same treatment.
In acute mode (at the time of the crisis)
Abundant use of lubricating eye drops and healing ointment (see below).
Eye closure, to avoid blinking which revives the opening and causes pain by fluttering of the eye.
Antibiotic coverage to prevent superinfections which are very real complications and can lead to an abscess.
In the most severe cases and under strict supervision, a therapeutic lens.
In the long term
Frequent use of lubricating eye drops to prevent the eye from drying out and "cracking" again.
Laser photokeratectomy for therapeutic purposes in the most disabling cases to homogenize the most superficial layers of the cornea.
Treatment of keratitis
The treatment of keratitis rests on two pillars: treatment of the cause and healing agents.
Causal treatment – There are several:
Removal of a corneal or subpalpebral foreign body.
Antiviral in case of herpes or shingles.
Removal of trichiasmatic eyelashes.
Entropion treatment.
Healing treatment
Thick artificial tear type Celluvisc®
Healing ointment or gel such as Vitamin A ointment or tear gel.
The right steps to take to combat pain
Unfortunately, there is no perfect pain relief treatment to eliminate the pain associated with keratitis.
It will therefore take approximately 48 hours (the healing time of the cornea) to perceive a real improvement.
During this unavoidable period, here are the right steps to take to reduce pain.
Discontinuation of contact lens wear – To limit the risk of infection and prevent the occurrence of an abscess.
Abundant eye hydration – Using thick, moisturizing eye drops (such as Celluvisc) or Vitamin A ointment (or both), according to the patient's preference. The ointment is administered following the diagram below.
Occlusive dressing – In case of unbearable pain, it is recommended to occlude the eye. In this case, the ointment should first be applied to the lower fornix, then the eye should be kept closed with a compress secured by adhesive tape.
Relieving unbearable eye pain
In cases of unbearable pain, certain comfort measures can be implemented:
Occlusive dressing – Close the eye for pain relief as described above.
Cold pack – Place a cold mask or ice pack on closed eyeballs to reduce inflammation and painful sensation.
Oral analgesics – The combination of paracetamol and codeine is the most effective analgesic administered orally. However, this treatment is sometimes poorly tolerated (nausea, vomiting, drowsiness) and should be used in addition to topical treatments.
Frequently Asked Questions
What is a corneal tear?
The eye is a small, fragile, but complex organ. It is common for patients who have suffered a retinal tear treated with laser to mention to the ophthalmologist, "I had a corneal tear."
To dispel any confusion, the ophthalmologist asks the patient if he has had pain (in which case it is keratitis or an ulcer, he will need to look for a scar on the first layer of the eye: the cornea) and if he has been treated by laser (in which case it is a retinal tear, a fundus examination will be necessary to check the laser and the absence of a new tear).
What is a corneal detachment?
Corneal detachment is frequently reported by patients who underwent retinal detachment surgery many years ago. These are two very different entities: the cornea is the first transparent layer of the eye, while the retina is the light-sensitive layer at the back of the eye.