Recurrent keratalgia – Cogan's dystrophy
Since a minor eye injury, you wake up at night or in the morning with eye pain, slightly blurred vision, redness, and watering. Sometimes the attacks are more painful, last longer, and force you to consult an ophthalmologist or self-medicate. Each time, it's a spontaneous corneal ulcer. Your condition is called recurrent keratalgia or recurrent corneal erosion. It's a common but often underdiagnosed corneal disease. It's caused by a weakening of the adhesion between the superficial layer of the cornea (epithelium) and its supporting membrane (basement membrane). This fragility can be genetic; this is known as Cogan's dystrophy. The disease is characterized by fragility and spontaneous rupture of the corneal epithelium, which can lead to the sudden appearance of an ulcer and pain. Healing, preventative and, if necessary, surgical treatments are possible depending on the severity and duration of corneal erosions.
What is recurrent keratalgia?
Recurrent keratalgia is a fragility of the epithelium, the protective and superficial layer of the cornea.
This fragility usually follows trauma, but it can also be of genetic origin or caused by chronic external aggression.
Even a small trauma can increase this fragility and lead to ulcers (keratitis) occurring spontaneously every morning upon waking (when opening the eyes).
A closer look at Cogan's dystrophy
Cogan's dystrophy is a genetic form of recurrent keratalgia linked to the TGFB1 mutation.
The mutation of this gene leads to a weakening of the bonds between the epithelium and its anchoring membrane (Bowman's membrane).
Clinically, the disease is characterized by a slightly irregular appearance of the corneal epithelium (1st layer of cells) forming small waves like a fingerprint.
Causes
Recurrent keratalgia is most often caused by an initial eye trauma, altering the surface of the cornea.
Corneal dystrophies sometimes occur; these are genetic diseases that result in a weakened adhesion between the epithelium and its basal layer. The most common is Cogan's dystrophy, described above.
To illustrate the condition, imagine that you have skin so fragile that the mere friction of clothing would tear it, resulting in a superficial cut and pain.
Risk factors
The main risk factors for recurrent keratalgia are:
Mechanical trauma (example: a projectile or a fingernail strike) is found to be a triggering factor in 2/3 of cases.
Corneal dystrophy – Cogan's dystrophy is found in approximately ⅓ of cases.
Nocturnal corneal edema – This is a physiological risk factor. At night, the cornea is better hydrated because our eyes are closed. It becomes engorged with water and thickens, increasing the fragility of the epithelium.
Patients with diabetes, dry eye syndrome, or ocular rosacea have a safe potential risk of developing recurrent keratalgia.
Diagnosis
The diagnosis of recurrent keratalgia is mixed: clinical and anamnestic (your history).
Clinical
The diagnosis is most often made during an emergency consultation for a painful flare-up. The ophthalmologist identifies a spontaneous ulcer, usually located below the visual axis, in the margin of the eyelid.
This ulcer often has an irregular shape and it is not uncommon for patients to have been treated for ocular herpes during previous consultations.
The ophthalmologist will also look for weaknesses: epithelial dystrophy.
It will also identify risk factors for recurrence: blepharitis, eyelid malposition.
Medical history
Your story is important; the diagnosis is often made even before the patient has been examined.
“Doctor, you are the third ophthalmologist I have consulted. I had an ulcer and it hasn't healed since! My eye hurts in the morning, it goes away during the day and starts again the next day.”
Signs and symptoms
The severity and duration of symptoms are proportional to the size of the ulcer. The larger the ulcer, the longer and more painful the attack. You may experience:
Mild to severe pain, especially upon waking.
A sensation of a foreign body.
Photophobia – Intense sensitivity to light.
A blurred vision.
A tear.
Symptoms can last from a few minutes to several hours, while the ulcer heals.
The disease follows a chronic, relapsing pattern. This means you will experience regular attacks for a period of time, which will then disappear for several weeks or even years!
With appropriate treatment and prompt diagnosis, the prognosis is excellent. Patients should be informed of the signs and symptoms of recurrent erosions so they can consult an ophthalmologist if necessary.
Preventive treatment in patients with recent and frequent seizures should be considered in order to minimize long-term complications.
Care and treatment
The treatment of recurrent keratalgia is based on healing the cornea and reducing the friction forces between your eyelids and the diseased epithelium.
The main objective is to facilitate re-epithelialization and the restoration of the basement membrane-epithelium complex.
Medical treatment
Moisturizers and healing agents – At each attack, moisturize your eye abundantly and help the epithelium to heal by applying vitamin A ointment in the cul-de-sac (area between the eyelid and the eye).
Cycloplegia (discussed) – During acute episodes of corneal erosion, the instillation of cycloplegic eye drops helps to limit pain.
Antibiotics and analgesics: Topical antibiotics are commonly prescribed to prevent bacterial infections in cases of epithelial defects. Oral analgesics such as ibuprofen can be helpful in reducing eye discomfort during acute episodes.
Osmoregulators – These are drops to be instilled in the evening before bedtime to reduce nocturnal corneal edema. This edema is a contributing factor to the development of ulcers upon waking.
Mechanical treatment – Dressing lens
Dressing lens – A soft contact lens can be left in place while the epithelium heals and stabilizes.
Occlusion – The technique is safe, quick, and reversible. Ointment is applied, and then the eye is closed with an eye washer. This is the best pain reliever.
Surgery – Therapeutic laser photokeratectomy (PKT)
The preferred technique for treating recurrent keratalgia resistant to medical treatment is laser therapy. The procedure is called PKT: therapeutic photokeratectomy.
Warning, the technique is not magic! It consists of creating a giant corneal ulcer before allowing the epithelium to heal evenly.
During the laser procedure, the surgeon removes the diseased epithelium, then uses an excimer laser to flatten the cornea evenly.
The treatment lasts a few seconds, but recovery takes several days!
Complications
Complications of recurrent corneal ulcers include:
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Recurrence – Development of new ulcers, including several years later.
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Corneal scarring – Rare and favored by superinfections.
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Infectious keratitis (superinfection) – Particularly in cases of prolonged use of contact lenses.