Recurrent corneal erosion: causes, symptoms and treatment

The cornea is the clear, dome-shaped structure at the front of the eye, with many nerves, which is why a scratch is so painful. Guy's and St Thomas' NHS Foundation Trust describes a corneal abrasion as a small scratch or graze to the cornea.

Most abrasions heal quickly. In a small number of cases, as Guy's and St Thomas' explains, the skin over the cornea heals but does not bind down entirely and can stick to the eyelid at night. It can then rip when you wake and open your eyes, or when the eyes move rapidly while dreaming. This is called recurrent corneal erosion syndrome.

Cambridge University Hospitals describes it as a small area of the corneal surface that may be more weakly attached than normal and can become loose during sleep, which may cause pain in the eye on waking.

Moorfields describes the typical pattern as an eye that becomes painful and watery during the night or first thing in the morning, and that may happen after being in dry, dusty environments.

• Sudden, often severe eye pain on waking or in the night.

• A watering, red eye.

• Blurred vision.

• Sensitivity to light.

• A history of an earlier scratch or injury to the same eye, sometimes months or years before.

Moorfields says if your eye becomes more red or painful or your sight becomes more blurred, you should seek advice from an eye hospital or attend A&E. Cambridge University Hospitals advises consulting an optician if you have these episodes and attending the emergency department if the pain is severe.

Guy's and St Thomas' says that for a corneal abrasion, symptoms that do not go away after 48 hours or that get worse need contact with the eye casualty department, and that outside clinic hours a GP or the emergency department can help.

Anyone who wears contact lenses and develops a painful red eye should be seen promptly, because contact lenses can sometimes cause infection of the cornea, according to Cambridge University Hospitals.

Diagnosis rests mainly on the story of an earlier injury and typical pain on waking, together with examination. Guy's and St Thomas' describes how an eye doctor examines the cornea with a microscope, uses an anaesthetic drop to make the examination more comfortable and puts a small amount of dye onto the eye to see the surface more clearly.

Moorfields notes that anaesthetic drops are given only to numb the eye for examination, and are not prescribed for use at home because they slow corneal healing if used regularly. Cambridge University Hospitals similarly warns they can cause permanent damage to the eye and vision if used more frequently.

Moorfields says that during an acute episode an antibiotic ointment or drop is usually prescribed to prevent infection, a pupil dilating drop may be given to relieve painful spasms of the iris, and over-the-counter painkillers such as paracetamol or ibuprofen can be used if there is no medical reason to avoid them. The time for an episode to settle varies from a few hours to a few days.

Moorfields says the only way to avoid recurrent erosions is the long-term use of lubricating drops and ointment, and that patients are often advised to continue lubrication for several months to prevent recurrence even if they do not experience any symptoms.

Guy's and St Thomas' says long-term use of lubricant eye ointments is the usual treatment, and that you might need lubricants for several weeks even after a simple abrasion so that the eyelid does not stick to the healing surface.

Dry, dusty environments can set off an episode according to Moorfields, so protecting the eyes and keeping up lubrication in such conditions is sensible.

Moorfields says long-term complications are rare. Infection may occur, but only very few patients develop permanent scarring of the cornea that affects vision.

Guy's and St Thomas' says most abrasions heal quickly and vision returns completely if the abrasion is superficial and no new infection follows. Left untreated, it says an abrasion can lead to inflammation and infection that may cause permanent damage.

On the NHS the first point of contact can be an optician, GP, eye casualty or emergency department, depending on severity and time of day. Recurrent episodes are usually reviewed by an ophthalmology service, which may consider procedures if lubrication alone is not enough.

Private ophthalmology can speed up assessment and procedures such as laser treatment. The ongoing treatment is the same, and it is worth ensuring the GP and optician know what has been advised.