Download the PDF

Download the PDF

Download the PDF


Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

ot<br />

Richard G. Lindsay BScOptom, MBA, FAAO DipCL<br />

Recurrent corneal erosion syndrome<br />

Recurrent corneal erosion (RCE) syndrome is a condition which is characterised by a<br />

disturbance at <strong>the</strong> level of <strong>the</strong> corneal epi<strong>the</strong>lial basement membrane resulting in<br />

defective adhesion and recurrent breakdown of <strong>the</strong> epi<strong>the</strong>lium 1 .<br />

RCE syndrome may occur secondary to<br />

corneal injury or else spontaneously 2 . In <strong>the</strong><br />

latter case, <strong>the</strong>re is often some predisposing<br />

factor, such as diabetes or a corneal<br />

dystrophy 1-3 . Management of <strong>the</strong> problem is<br />

usually aimed at regenerating or repairing<br />

<strong>the</strong> epi<strong>the</strong>lial basement membrane so as to<br />

restore <strong>the</strong> adhesions between <strong>the</strong><br />

epi<strong>the</strong>lium and <strong>the</strong> anterior stroma.<br />

Aetiology<br />

The corneal epi<strong>the</strong>lial basement membrane<br />

complex is responsible for <strong>the</strong> tight adhesion<br />

of <strong>the</strong> epi<strong>the</strong>lial basal cell layer to <strong>the</strong><br />

underlying stroma. The primary abnormality<br />

with RCE syndrome is poor adhesion of <strong>the</strong><br />

epi<strong>the</strong>lium to Bowman’s layer due to a<br />

failure to establish or maintain normal<br />

adhesion complexes. Multiple recurrences are<br />

common, because <strong>the</strong> basal epi<strong>the</strong>lial cells<br />

require at least 8 to 12 weeks to regenerate<br />

or repair <strong>the</strong> epi<strong>the</strong>lial basement membrane 2 .<br />

The most common cause of RCE syndrome<br />

is trauma to <strong>the</strong> cornea. In <strong>the</strong>se cases,<br />

patients will generally give a history of<br />

previous oblique corneal abrasion with an<br />

object such as a fingernail, piece of paper or<br />

twig 4 . The original injury is generally well<br />

recalled by <strong>the</strong> patient as it is usually<br />

followed by several days of pain, watering<br />

and photophobia. The first recurrence may<br />

<strong>the</strong>n not occur for quite a few months after<br />

<strong>the</strong> original trauma. Epi<strong>the</strong>lial injuries where<br />

<strong>the</strong> basement membrane is preserved are<br />

unlikely to be followed by recurrent corneal<br />

erosions.<br />

RCE syndrome can also occur<br />

spontaneously, although in this situation<br />

<strong>the</strong>re is often some predisposing factor. For<br />

example, many corneal dystrophies are<br />

associated with recurrent corneal erosions.<br />

Epi<strong>the</strong>lial basement membrane dystrophy<br />

(EBMD, also known as Cogan’s microcystic<br />

dystrophy or map-dot-fingerprint dystrophy)<br />

is commonly associated with RCE syndrome,<br />

with about half <strong>the</strong> patients with recurrent<br />

epi<strong>the</strong>lial erosions exhibiting EBMD 3 . O<strong>the</strong>r<br />

corneal dystrophies which can lead to<br />

recurrent erosions include Reis-Bücklers’<br />

dystrophy (a dystrophy occurring at <strong>the</strong><br />

level of Bowman’s layer, also known as<br />

ring-shaped dystrophy), stromal dystrophies<br />

such as granular and lattice, and Fuchs’<br />

endo<strong>the</strong>lial dystrophy 4 .<br />

Spontaneous recurrent erosions, with an<br />

autosomal dominant inheritance pattern,<br />

have been described in 40 members of one<br />

family 3 . RCE syndrome also appears to be<br />

more common in patients with diabetes<br />

mellitus (due to basement membrane<br />

thickening and abnormal adhesion<br />

complexes) as well as in post-operative<br />

patients who have undergone ocular surgical<br />

procedures such as cataract extraction (with<br />

intraocular lens implantation) or refractive<br />

surgery 2 .<br />

Consequently, for patients who present<br />

with signs and symptoms of RCE syndrome, a<br />

careful history and examination of <strong>the</strong><br />

corneae should be undertaken to ensure<br />

<strong>the</strong>re are no underlying factors which may<br />

have predisposed <strong>the</strong> patient to this<br />

condition. This applies even in cases where<br />

<strong>the</strong>re is a history of injury to <strong>the</strong> cornea – a<br />

defect in <strong>the</strong> epi<strong>the</strong>lial basement membrane<br />

complex may have been present before <strong>the</strong><br />

initial trauma 3 .<br />

Presentation<br />

Patients will usually present with a history of<br />

pain (nearly always unilateral) on waking,<br />

associated with lacrimation, photophobia<br />

and blurred vision. External eye examination<br />

will generally show a corneal abrasion, often<br />

centrally located, which stains brightly with<br />

fluorescein (Figure 1). The abraded area<br />

tends to create loose edges with moderate to<br />

large epi<strong>the</strong>lial flaps commonly forming. A<br />

brownish granular oedema (brawny oedema)<br />

may occupy <strong>the</strong> underlying anterior stroma.<br />

The tendency towards central location and<br />

dense secondary oedema can cause vision to<br />

be significantly affected 2 .<br />

Recurrent corneal erosions can be classed<br />

as ei<strong>the</strong>r macroform or microform 5 . With <strong>the</strong><br />

former, <strong>the</strong>re will be severe pain persisting<br />

for hours to days as a result of a large area<br />

of epi<strong>the</strong>lium being separated from <strong>the</strong><br />

cornea (as in Figure 1). In post-traumatic<br />

cases, <strong>the</strong> macroerosion will always occur at<br />

Figure 1: Recurrent (macroform) corneal erosion<br />

<strong>the</strong> site of <strong>the</strong> original abrasion. Microform<br />

recurrent erosions are characterised by<br />

intraepi<strong>the</strong>lial microcysts with a minor break<br />

in <strong>the</strong> epi<strong>the</strong>lium. These will usually be<br />

associated with very brief episodes of pain,<br />

lasting seconds or minutes.<br />

Corneal topographic analysis (using<br />

computerised videokeratography) often<br />

reveals focal areas of corneal flattening<br />

(called “corneal topographic lagoons”) in<br />

eyes with RCE syndrome 6 . This is an<br />

important finding, as <strong>the</strong> identification of<br />

areas of focal abnormality in RCE syndrome<br />

remains a significant clinical problem in<br />

those patients with frank symptoms but no<br />

evident epi<strong>the</strong>lial abnormalities. Figure 2<br />

shows such a corneal topographic lagoon in<br />

a patient with a history of RCE syndrome.<br />

Management<br />

Management of RCE syndrome is usually<br />

aimed at regenerating or repairing <strong>the</strong><br />

epi<strong>the</strong>lial basement membrane so as to<br />

restore <strong>the</strong> adhesions between <strong>the</strong><br />

epi<strong>the</strong>lium and <strong>the</strong> anterior stroma. In mild<br />

cases, <strong>the</strong> condition may resolve<br />

spontaneously within a few hours. More<br />

often, however, treatment is required to<br />

promote healing and relieve <strong>the</strong> patient’s<br />

symptoms. It should also be noted that <strong>the</strong><br />

healing rate for an abrasion occurring as a<br />

part of RCE syndrome is generally slower than<br />

<strong>the</strong> normal rate for a similar abrasion caused<br />

by o<strong>the</strong>r factors.<br />

There are two options for treatment<br />

during <strong>the</strong> acute stage of recurrent erosion.<br />

The first one is just to apply a pressure patch<br />

to <strong>the</strong> affected eye for 24 hours, combined<br />

with a mild cycloplegic and a prophylactic<br />

antibiotic ointment. For more severe cases,<br />

42<br />

April 6, 2001 OT<br />


where <strong>the</strong>re is extensive disadhesion of <strong>the</strong><br />

epi<strong>the</strong>lium, mechanical debridement of <strong>the</strong><br />

loose epi<strong>the</strong>lium is required. Debridement<br />

provides for a smoo<strong>the</strong>r epi<strong>the</strong>lial basement<br />

membrane which can <strong>the</strong>n be resurfaced with<br />

a healthy epi<strong>the</strong>lium. Debridement of loose<br />

epi<strong>the</strong>lium assists healing and resolves pain<br />

sooner, but does nothing to prevent<br />

recurrences. This is not that surprising, as<br />

with RCE syndrome <strong>the</strong> problem is more one<br />

of epi<strong>the</strong>lial adherence ra<strong>the</strong>r than epi<strong>the</strong>lial<br />

resurfacing 3 . Pressure patching will always be<br />

required following debridement and it is<br />

often suggested that <strong>the</strong> patient should be<br />

patched bilaterally to completely immobilise<br />

<strong>the</strong> eyes 2 . Patching should only be done for<br />

up to 72 hours and if <strong>the</strong> corneal abrasion<br />

has not resolved within this time, <strong>the</strong>n <strong>the</strong><br />

use of a <strong>the</strong>rapeutic (bandage) soft contact<br />

lens should be considered.<br />

Prophylactic treatment of RCE syndrome is<br />

aimed more at preventing recurrences of <strong>the</strong><br />

corneal erosions. Fluid accumulating beneath<br />

<strong>the</strong> epi<strong>the</strong>lium during <strong>the</strong> night – caused by<br />

<strong>the</strong> tears becoming hypotonic during sleep –<br />

leading to disadhesion of <strong>the</strong> epi<strong>the</strong>lium,<br />

and adherence of <strong>the</strong> epi<strong>the</strong>lium to <strong>the</strong><br />

tarsal conjunctiva, are thought to be <strong>the</strong> two<br />

major factors leading to recurrence.<br />

A lubricating ointment – such as<br />

Lacrilube® (Allergan) – can be used as a<br />

prophylactic treatment in <strong>the</strong> management of<br />

RCE syndrome, through application at<br />

bedtime to prevent adhesion between <strong>the</strong><br />

corneal epi<strong>the</strong>lium and <strong>the</strong> eyelid during<br />

sleep 3 . However, using just a lubricating<br />

agent as a prophylactic treatment for RCE<br />

syndrome may not always be successful, as<br />

this does little to prevent <strong>the</strong> fluid intake by<br />

<strong>the</strong> cornea during <strong>the</strong> night, which is<br />

generally believed to cause <strong>the</strong> disadhesion<br />

of <strong>the</strong> epi<strong>the</strong>lium 3,5 . In view of this, an<br />

alternative approach to prophylaxis is to use<br />

an ophthalmic ointment, such as Muro 128®<br />

(Bausch & Lomb), which also incorporates a<br />

hypertonic agent to promote corneal<br />

desiccation.<br />

Ano<strong>the</strong>r form of prophylaxis for RCE<br />

syndrome is to use a bandage contact lens.<br />

This form of treatment will generally be<br />

adopted when application of <strong>the</strong> hypertonic<br />

ointment (or drops) has been unsuccessful in<br />

preventing recurrences. A thin medium to<br />

high-water content, loosely fitting<br />

<strong>the</strong>rapeutic soft contact lens worn on a<br />

continuous (extended wear) basis for at least<br />

two months will protect <strong>the</strong> epi<strong>the</strong>lium while<br />

it reattaches itself to <strong>the</strong> basement<br />

membrane. The new silicone hydrogel contact<br />

lenses – with <strong>the</strong>ir greatly increased oxygen<br />

transmissibility – are also a good option in<br />

this regard, as <strong>the</strong>y have <strong>the</strong> potential to<br />

promote faster corneal healing through <strong>the</strong><br />

delivery of higher levels of oxygen to <strong>the</strong><br />

cornea during extended wear.<br />

The wearing of a <strong>the</strong>rapeutic contact lens<br />

may precipitate corneal erosions in some<br />

patients. The o<strong>the</strong>r major problem with this<br />

form of treatment relates to <strong>the</strong> risks<br />

associated with <strong>the</strong> extended wear of a soft<br />

contact lens 7 , especially when that lens is<br />

worn continuously for 60 days or more. In<br />

particular, <strong>the</strong> risk of corneal infection is<br />

greatly increased by <strong>the</strong> wearing of a soft<br />

contact lens on a continuous basis 8 , so<br />

consideration should be given to using a<br />

prophylactic antibiotic medication in<br />

combination with <strong>the</strong> contact lens for <strong>the</strong><br />

duration of <strong>the</strong> extended wear.<br />

The nightly administration of an<br />

ophthalmic ointment or eyedrop (preferably<br />

<strong>the</strong> former), which incorporates both a<br />

lubricating agent (to prevent adhesion<br />

between <strong>the</strong> corneal epi<strong>the</strong>lium and <strong>the</strong><br />

eyelid) and a hypertonic agent (to produce<br />

corneal desiccation), is certainly a more<br />

conservative treatment option with less<br />

associated risk compared to a bandage<br />

contact lens used on an extended wear basis.<br />

To be successful, patients should be advised<br />

that application of <strong>the</strong> ointment may need<br />

to be continued for a period of between 4 to<br />

12 weeks.<br />

In severe cases, where nei<strong>the</strong>r a bandage<br />

contact lens or a hypertonic agent is<br />

successful in preventing frequent recurrences,<br />

<strong>the</strong>re are a number of o<strong>the</strong>r treatment<br />

options. Anterior stromal puncture is very<br />

effective in managing post-traumatic<br />

macroerosions. Multiple micropunctures made<br />

in <strong>the</strong> anterior stroma incite focal scarring<br />

leading to more secure epi<strong>the</strong>lial adhesion.<br />

Alternatively, superficial epi<strong>the</strong>lial<br />

keratectomy involves debriding <strong>the</strong><br />

epi<strong>the</strong>lium, usually just in <strong>the</strong> affected area,<br />

also with subsequent scarification. The<br />

resultant scarring with <strong>the</strong>se procedures<br />

means that treatment near or on <strong>the</strong> visual<br />

axis should be avoided if possible 1,3 .<br />

Photo<strong>the</strong>rapeutic keratectomy (PTK) is<br />

often effective when ano<strong>the</strong>r treatment has<br />

failed. PTK can be used in resistant cases of<br />

recurrent erosions to smooth <strong>the</strong><br />

subepi<strong>the</strong>lial corneal surface, creating a<br />

substrate more conducive to epi<strong>the</strong>lial<br />

migration and adhesion 9 . The treatment<br />

involves mechanical debridement of <strong>the</strong><br />

epi<strong>the</strong>lium followed by a plano ablation of<br />

usually less than 10 microns. This may be<br />

combined with a refractive ablation in<br />

suitable ametropic patients. The ablation<br />

zone diameter is generally determined by <strong>the</strong><br />

Figure 2:<br />

Computerised videokeratography<br />

showing a typical topographic<br />

lagoon – a small focal (blue) area of<br />

corneal flattening just slightly<br />

superotemporal to <strong>the</strong> corneal vertex –<br />

in a patient with RCE syndrome<br />

extent of changes to <strong>the</strong> epi<strong>the</strong>lial basement<br />

membrane.<br />

The prognosis for a patient with RCE<br />

syndrome is generally quite good. The<br />

condition will usually heal if <strong>the</strong> underlying<br />

cause is properly diagnosed and remediated<br />

(if this is possible). If <strong>the</strong> condition is<br />

chronic, <strong>the</strong> patient must be instructed on<br />

appropriate prophylactic measures and<br />

advised of <strong>the</strong> need for indefinite<br />

continuation of procedures. Most<br />

importantly, patients should be reassured<br />

that most cases of RCE heal eventually or are<br />

controllable without visual loss.<br />

About <strong>the</strong> author<br />

Richard G. Lindsay is a Senior Fellow at <strong>the</strong><br />

Department of Optometry and Vision<br />

Sciences, University of Melbourne, Victoria,<br />

Australia, and an optometrist in private<br />

practice in East Melbourne.<br />

References<br />

1. Kanski, J. (1994) ‘Clinical<br />

Ophthalmology’. 3rd ed. Butterworths,<br />

London, 135-136.<br />

2. Catania, L. (1995) ‘Primary Care of <strong>the</strong><br />

Anterior Segment’. 2nd ed. Appleton &<br />

Lange, Conneticut, 237-241.<br />

3. Brown, N. and Bron, A. (1976)<br />

“Recurrent erosion of <strong>the</strong> cornea”. Brit.<br />

J. Ophthal. 60: 84-96.<br />

4. Waring, G.O., Rodrigues, M.M. and<br />

Laibson, P.R. (1978) “Corneal<br />

dystrophies. 1. Dystrophies of <strong>the</strong><br />

epi<strong>the</strong>lium, Bowman’s layer and stroma”.<br />

Surv. Ophthalmol. 23: 71-122.<br />

5. Chandler, P.A. (1945) “Recurrent erosion<br />

of <strong>the</strong> cornea”. Am. J. Ophthalmol.<br />

28: 355-367.<br />

6. McGhee, C.N.J., Bryce, I.G., Anastas, C.N.,<br />

Webber, S.K., Burvill, M. and Murray, A.T.<br />

(1996) “Corneal topographic lagoons: a<br />

potential new marker for post-traumatic<br />

recurrent corneal erosion syndrome”. Aust.<br />

NZ J. Ophthal. 24: 27-31.<br />

7. Bruce, A.S. and Brennan, N.A. (1990)<br />

“Corneal pathophysiology with contact<br />

lens wear”. Surv. Ophthalmol. 35: 25-58.<br />

8. Brennan, N.A. and Coles, M.L.C. (1997)<br />

“Extended wear in perspective”. Optom.<br />

Vis. Sci. 74: 609-623.<br />

9. Harkins, T. (1995) “The excimer laser and<br />

photo<strong>the</strong>rapeutic keratectomy”.<br />

Clin. Eye Vis. Care 7: 103-106.<br />

www.optometry.co.uk 43

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!