What is a recurrent corneal erosion?
Corneal
abrasion
(green when seen with fluorescein drops)
Recurrent
corneal erosion is a painful eye condition, although your eye heals
after a few hours or days. It is caused by a scratch on the surface
of the eye in the previous months.
Although the first injury heals, the healing is not perfect and the
'scratch' returns over the next months for no apparent reason.
This page describes what is happening, and how you can reduce the
number of recurrences.
The cornea, and the corneal epithelium
the
cornea, and its
epithelium, shown in red enlarge
The cornea is the transparent 'window' of the eye at the front.
It is covered with a very thin skin, the epithelium.
The original injury, the abrasion
the
corneal injury..the abrasion enlarge
Typically the condition starts when the surface of the eye is scratched,
possibly by a finger nail. A patch of epithelium is scratched off or wrinkles
up, leaving a bare patch of cornea.
As the cornea has many nerves, this
injury feels exquisitely painful, like a needle.
The abrasion always heals and the pain goes.
The
healing takes 1mm a day from each side, so a large 7 mm abrasion takes
about 4 days, less in children, longer if you are older.
The examination
Recurrent corneal
abrasion
green when seen with fluorescein drops , but are sometimes difficult
to see
When a doctor looks into your eye, even with the microscope slit lamp
in the Eye Department, it may be very difficult to see the injury.
Sometimes it may not be apparent at the first examination. The doctor
or nurse uses a yellow dye, called fluorescein, to examine your
eye, and this dye sticks to a bare patch of cornea if there is one.
There may not actually be a bare patch ..the cornea may just be
wrinkled and very loosely attached. Occasionally there is an underlying map-dot-finger-print dystrophy (genetically inherited sometimes), or epithelial microcysts.
What is happening?
there are tiny
pegs that hold each cell in place
(hemi-desmosomes)
blepharitis with blocked glands causes irregular tears and may help to cause recurrent abrasions
Normally
the epithelium sticks down to the layer underneath (the basement membrane)
firmly. Tiny pegs underneath the cells that make up the epithelium keep
the cells stuck on to the basement membrane.
This is like painting on
a wall: if you paint on the undercoat first, and then paint on the
top coat, when the paint dries it will be well stuck down.
However,
these pegs may take 6-12 months to reform properly after the original
injury. During this time the epithelium may be prone to slipping and
sliding, and this slipping and sliding causes this condition.
This is like painting on a bare surface with a 'top coat' of paint,
when there is no 'undercoat'. The paint will dry but peel off really
easily.
A few people will
this condition have inherited genes that make this sticking process faulty,
but this is quite unusual.
Certainly if your condition keeps happening
year after a year a corneal specialist may detect this condition.
A
second reason for the faulty sticking may lie in your tears.
The glands in your eyelid, especially your lower lid, make secretions
that help tears to spread. If these glands get blocked, your tears do
not spread properly, and the eyelid may stick to the epithelium and pull
it off before the pegs have firmly fixed it in position.
If you clean your lids as below, the glands start to make their secretions
again, and the process stops.
In addition to the regular cleaning of the eyelids, sometimes using
a cream at night can stop the sticking (the 'sticking' of the eyelid
to the epithelium occurs when you wake up in the morning).
The injury returns: the 'recurrent erosion'
the original abrasion, very painful indeed
All of a sudden, perhaps a month after the first injury, your eye starts
to feel exquisitely painful again.
It is as though the first injury recurs all by itself. Again this injury
heals, and your eye starts to feel comfortable again.
If the patch of cornea with the recurrent abrasion
is small, as it usually is, your eye may heal after a few hours.
A larger patch will take days to heal.
Occasionally, you may not remember the original injury, and all of a sudden
the condition develops.
RCE syndrome may be related to
- get collagen under bowmans and stops hemidesmosome function and get reduplication of bowmans
- Map dot finger print dystrophy
- Granular dystrophy
- Granular dystrophy even after graft
..delaminate if superficial, catch early
- Thygersos
Typical treatment for corneal abrasion
- chloramphenicol ointment 4 times a day at night for 4 days (longer for a larger abrasion)
- continue chloramphenicol ointment at night for 3 weeks as a lubricant
- cyclopentolate 1% twice daily for 2 days then
- cyclopentolate 1% at night for 1 week, then stop
- stop smoking as it delays healing (electronic cigarettes much, much safer)
- note cyclopentolate...
- halves the pain, but blurs sight (poor near vison)
- twice a day when eye painful, only at night when no ache
- pad eye/bandage contact lens if severe
- if using a a bandage a contact lens
- change lens every 2 weeks if possible
- use chloramphenical minims if there is an abrasion present
To prevent a cycle of recurrences
- treat the abrasion as above
- stage 1
- lubricants every night : VitaApos
- if there is blepharitis: lid hygiene (see below) usually helps (with or
without antibiotic cream)
- hourly preservative free drops, such as Hylofort (many others, see)
- try for 3 months..it takes 3 months for the epithelium to adhere
- stopping smoking will make a recurrence less likely
- stage 2
- doxycycline 100mg once a day (not if you are pregnant)
It
takes a few weeks to work, and works for several weeks after it is
stopped. One 3 month course is usually helpful, but occasionally longer
treatment is needed.
- Also add prednisolone drops see
- stage 3
- Healthy diet, as for blepharitis, standard healthy diet, may help a little
- portions of vegetables/day
- 2 portions fruit
- fish, especially oily fish, small portions twice week (eg salmon, tuna, sardine, mackerel, tuna, trout)
- very little saturated fat and transfats (saturated fat: dairy food, red meat (beef, lamb, pork))
- pulses such as soya beans, other beans, lentils, have plant sterols..these lower cholesterol
- no added salt, no sugar (cakes, chocolates, sweetened drinks)
- vitamin D..best achieved by walking 1-2 hours in daylight
- other treatments, review
Lid hygiene
Blepharitis treatment NHS
Warm
compress
- Hot eye compresses (can be prescribed by GP) or
- Use clean face cloth soaked in warm water, as
hot as your eyelids can stand.
- Bathe your eye (closed) for 5-10 minutes. Rewarm
the cloth if it gets cold. This makes the debris easier to remove, as
below.
Clean eyelids
gently clean
with a cotton bud, looking in mirror
- Blephaclean wipes or
- Clean the edge of your eyelids
(the eyelash edge) with a wet cotton bud.
- Gently
scrape off the debris moving the bud side to side.
- Looking in a mirror,
pull your lower eyelid down with the index finger of one hand,
and gently but firmly wipe the bud along the edge of the lid to scrape
the debris off.
- With your chin up try the same on the upper, but this is harder.
- First try warm sterile water, that is boiled water allowed to cool
but still warm. (Warm tap water is usually quite safe.)
Other treatments
- If the patch of epithelium is very loose, your doctor
may scrape it off to allow fresh epithelium to grow in: this often helps.
This is called debridement.
- There are more complex treatments available from corneal specialists, but these
are not usually needed and not discussed here. They include micro-puncture of
the loose patch, and laser.
- Some experts recommend contact lenses (see and here and here).
- There is one report botulinum
toxin may help by closing the eyelid more completely at night, but this
would not be necessary for most patients.
- there may be an underlying corneal dystrophy and here.
What to expect
Typically you may notice recurrences
even with these 'preventative' measures, but gradually the painful episodes
become fewer with longer between. Also, instead of the pain lasting hours,
your eye should start to heal more quickly, perhaps after half an hour.
Over a year you should start to feel a lot better,
and have very little problem then.
