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The conjunctiva is a thin, transparent mucous membrane, which lines the inner surface of the eyelids and covers the sclera (the white part of the eye). The conjunctiva contains glands which produce secretions that help to keep the eyes moist, and antibodies, which reduce infection.
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Viral conjunctivitis
Several different viruses can cause
conjunctivitis. Some, such as entero- and
adenoviruses, can spread rapidly through
communities leading to epidemics of
conjunctivitis (e.g. Apollo red eye), while
others primarily cause skin infections
(molluscum contagiosum, herpes infection),
and the eye can be infected if the eyelids
are involved.
Entero- or adenoviral
This is an epidemic form of conjunctivitis
which almost always affects both eyes. The
patient may complain of a foreign body
sensation, with watering, discharge,
redness, and swelling of the lids. They may
also complain of the eyes being sensitive to
light, with blurred vision. The eyes appear
red, with discharge, but the cornea and
pupil are usually normal. In severe cases
there may be small haemorrhages in the
conjunctiva. The patient may also complain
of upper respiratory tract symptoms and
other generalized symptoms (sore throat,
fever and headache). The eye infection lasts
7-14 days, and usually gets better on its
own. The condition is very contagious:
health workers should wash their hands
after examining a patient and disinfect the
instruments they have used.
Treatment: There is no specific treatment
for viral conjunctivitis, and the condition
gets better on its own. Antibiotic eye drops
prevent secondary infection from bacteria,
and tetracycline eye ointment can be
soothing. Topical steroid eye drops should
never be given for conjunctivitis due to
Health education: The patient should be
told that the condition is very infectious,
that they should not share face towels, and
should wash their hands regularly. In parts
of the world where traditional eye remedies
are commonly used, the patient should
be advised not to use traditional remedies
and needs to be told that the infection will
get better.
Molluscum contagiosum
The virus that causes the skin infection
known as molluscum contagiosum can also
infect the eye, if the molluscum is on the
eyelid. The patient (usually a child) presents
with a single or multiple eyelid lesions,
which are small, round, waxy, whitish,
umbilicated nodules on the eyelid. The
affected eye will be red, with some
discharge. Patients with HIV/AIDS can
have multiple lesions (Figure 1).
Tissa Senaratne
Consultant Ophthalmologist, Teaching
Hospital, Kandy, Sri Lanka.
Clare Gilbert
Senior Lecturer, International Centre for Eye Health,
London School of Hygiene and Tropical Medicine,
Keppel Street, London WC1E 7HT, UK.
The conjunctiva is a thin, transparent mucous
membrane, which lines the inner surface of the
eyelids and covers the sclera (the white part of the
eye). The conjunctiva contains glands which produce
secretions that help to keep the eyes moist, and
antibodies, which reduce infection.
Conjunctivitis means ‘inflammation of the
conjunctiva’, and the commonest cause is infection
by viruses or bacteria. Conjunctivitis can also be due
to chemical irritants, traditional eye remedies or
allergy. It is usual for both eyes to be affected in
infectious cases. The patient notices that the eyes
are red and uncomfortable, and there is discharge
which may make the eyelids stick together in the
morning. The vision is usually not affected. On
examination the eyelids may be slightly swollen,
the eyes are red, and there may be some visible
discharge. The cornea should be bright, and the
pupils should be round, regular and react to light.
Conjunctivitis due to infection occurs at all ages, but
some of the less common causes affect particular
age groups (Table 1). There is one form of conjuncti-
vitis which can be sight threatening – that due to
gonococcal infection.
Table 1. Causes of conjunctivitis, and who is primarily affected
traditional eye
Uncommon Can affect one or
both eyes
Can affect one or
both eyes
Allergy Uncommon Usually affects
both eyes
Chlamydia Can cause
conjunctivitis of
the newborn
Causes trachoma,
which usually
affects both eyes
Usually affects both
May be severe and
sight threatening
May affect one or
both eyes. May be
severe and sight
May affect one or
both eyes. May be
severe and sight
Viral infection Uncommon Usually affects
both eyes
Usually affects
both eyes
Cause of
Newborn babies Children Adults
Continues over page
Fig 1. Patients with HIV/AIDS can have multiple lesions caused by molluscum contagiosum
Ben Naafs
Treatment: This condition does not get
better on its own, and the treatment
consists of removing the lid lesion, with a
curette or other blunt instrument.
Health education: Mothers and adult
patients can be shown how to remove the
skin lesions.
Herpes simplex blepharo-
Again, this condition is more common in
children. The child presents with fluid filled
vesicles on the skin around one eye, and a
red, sore eye which may be sensitive to
light. The treatment is topical antiviral eye
drops or ointment (e.g. idoxuridine, acyclovir).
Health education: Steroid eye drops
should never be used as they make the
infection much worse.
Acute conjunctivitis
Conjunctivitis due to bacteria differs from
infection due to viruses, as it is more likely
to affect only one eye, and the amount of
discharge and lid swelling is usually greater.
The patient complains of irritation, a foreign
body sensation, and the eyelids are stuck
together in the mornings.
Treatment: Broad-spectrum topical
antibiotic such as tetracycline eye ointment.
Conjunctivitis due to
Certain groups of individuals are at risk of a
very severe form of bacterial conjunctivitis
due to the Gonococcus organism (which
causes gonorrhea): i) newborn babies, who
acquire the infection during delivery; ii)
adults, who acquire the infection during
sexual activity; and iii) individuals of any age
who have used urine infected with
Gonococcus as a traditional remedy. Taking
a history is, therefore, very important.
Infection with Gonococcus should be
suspected in any age group (including
babies) if the eyelids are very swollen, if the
discharge is thick and profuse, and if the
cornea is ulcerated or perforated (Figure 2).
Treatment of babies: Clean the eyelids,
and show the mother how to do this. Gently
open the eyes, and instill tetracycline eye
ointment, or other antibiotic eye ointment,
showing the mother how to do this. Make
sure she can instill the ointment, give her a
tube of tetracycline (or other antibiotic), and
tell her to put it in both eyes every hour. Tell
the mother that this is a very serious
infection, and that she and her baby should
go urgently to an eye department as she
and her baby need an injection of antibiotic.
Treatment of adults: Prescribe antibiotic
eye drops or ointment, and tell the patient
to use the treatment hourly. They should be
told that the infection is serious, and that
they should go to an eye department.
Health education: If a newborn baby has
conjunctivitis and Gonococcus is suspected,
the mother should take her baby to an eye
clinic immediately for treatment. She
should also should be treated as well as her
husband/partner. Communities should be
warned of the potential dangers of traditional
eye remedies, particularly urine, which may
have come from someone with gonorrhea.
Chronic bacterial
Bacterial infection of the eyelid margins
can lead to chronic conjunctivitis. The patient
complains of sore eyelids and sore eyes with
little discharge. On examination, the eyelid
margins are thickened, slightly inflamed and
crusty. The eyes themselves may look normal
or slightly red.
Treatment: As the source of the
conjunctivitis is infection of the eyelids,
treatment is aimed at the eyelids and
consists of tetracycline eye ointment applied
to the lid margins three times a day, after
cleaning the lid margins to remove the crusts.
Chlamydial conjunctivitis
Chlamydia are organisms which have
some characteristics of viruses and some
of bacteria. They can cause conjunctivitis
in three groups of individuals: i) newborn
babies, who acquire the infection
during delivery; ii) children, who develop
trachoma; and iii) young adults, who
acquire the infection during sexual activity.
Neonatal chlamydial
The infection starts a few days after birth,
and the mother notices that the eyelids are
swollen and there is discharge. The baby
may also have chlamydial infection of the
lungs, ears and nose.
Treatment: Clean the eyelids, and instill
tetracycline eye ointment. Show the
mother how to do this and tell her to instill
the ointment four times a day. The baby
should also have a course of oral erythro-
mycin to clear the infection from other parts
of the body.
Trachoma infection principally affects
children. The child may not complain of
symptoms or may have some discomfort
and discharge. On examination, the upper
eyelids may be slightly swollen and drooping,
and the eyes will be slightly red, with some
discharge. The diagnosis is confirmed by
everting the upper eyelid and examining the
conjunctiva over the tarsal plate. Evert the
lid by i) ask the child to look down; ii) get
hold of the lashes of the upper eyelid; iii)
place a narrow object, such as a matchstick
2-3 mm above the lid margin, holding it
parallel to the lid margin; iv) fold the eyelid
upwards, against the matchstick. The eyelid
will then evert.
Active infection causes two eye signs:
trachoma with follicles ‘TF’ (Figure 3), and
trachoma with intense inflammation ‘TI’
(Figure 4).
Fig. 2. Baby suffering from conjuntivitis
due to Gonococcus
Treatment: The child should be treated
either with topical tetracycline eye ointment,
three times a day for six weeks, or they
should be given a dose of azithromycin
20 mg per kg body weight.
Health education: Trachoma is a
community disease which affects disadvan-
taged households. Seeing a child with
trachoma almost certainly means that
there are other children from the same
community who are infected, and there are
likely to be adults requiring lid surgery.
Health education should focus on the SAFE
strategy (see Community Eye Health Journal
Issue 52, 2004).
Pak Sang Lee
Fig 3. Trachoma TF. There are at least five
follicles (small, whitish spots) on the
everted eye lid, which are at least 1 mm
Fig 4. Trachoma TI. Very active infection
when at least half of the blood vessels of
the conjunctiva on the upper eyelid
cannot be seen because the conjunctiva
is so thickened and inflamed
There are two forms: an acute form and
a chronic form.
Acute allergic
The adult or child develops sudden and
severe itching of the eyes and eyelids as a
result of coming into contact with something
the person is allergic to (e.g. pollen, cats).
The eyelids and conjunctiva become
markedly swollen and there is profuse
watering of the eyes, which usually do not
become red. The condition gets better on its
own very quickly.
Health education: The person needs to try
and find out what led to the reaction (e.g.
eating certain food; sitting under a particular
tree) and try to avoid this in the future.
They should be told not to rub their eyes,
as this makes the condition worse.
Chronic allergic
conjunctivitis (vernal
The cause of vernal keratoconjunctivitis is
not known, but it is often associated with
asthma or eczema and is probably due to a
longstanding allergic reaction. The condition
usually starts between the ages of three and
25 years, and the patient complains of chronic
itching, a thick, clear, stringy discharge, light
sensitivity, blurred vision and discoloration
of the eyes. The diagnosis is made by
everting the eyelids when large, flat
‘papillae’ become visible (Figure 5).
Treatment: Treatment is not easy at the
primary level, and if the symptoms are
severe, or the cornea looks hazy, the
management is referral to an eye
department (see pages 76-78).
Many different substances put in the
eyes can cause chemical reactions (e.g.
traditional remedies, reaction to the
preservatives in eye drops). The findings
are similar to that seen in viral conjunctivitis,
and so the history is important.
Treatment: The person should be told to
stop instilling the substance that has
caused the reaction. Tetracycline eye
ointment can be soothing and will prevent
secondary bacterial infection.
Health education: People should not instill
anything in their eyes that has not been
prescribed for them, and they should throw
away eye drops after the bottle has been
open for one month or more.
Conjunctivitis is common but is only rarely
sight threatening. However, accurate
diagnosis and prompt treatment at the
primary level is very important as it instills
confidence in the community, and reduces
the risk that people may first try traditional
remedies, which can, and do, lead
to blindness.
‘Conjunctivitis is
common, but is only
rarely sight threatening’
Visual acuity chart
Clean swabs for cleaning eyes
Tetracycline eye ointment
Povidone iodine eye drops
Equipment needed at the
primary level to diagnose
and manage conjunctivitis
Fig 5. Eversion of the upper tarsus shows
marked conjunctival papillae in vernal
Tissa Senaratne
Table 2. Clinical features of conjunctivitis, by cause
Cause of
Unilateral (U)
or bilateral (B)
Discharge Redness Other symptoms or
Viral, epidemic form B Watery +++,
+/- conj. haemorrhage
Fever, sore throat
Tetracycline eye ointment;
povidone iodine eye drops
Viral – herpes U Watery +/- Vesicles on the eyelid Topical antiviral
Viral – molluscum U Watery +/- Molluscum on lid Remove molluscum
Bacterial –
U or B Purulent
+++ None Tetracycline eye ointment
or other antibiotic
Bacterial –
B Purulent
++++ Marked lid swelling.
May have corneal ulcer
Frequent antibiotic
Chlamydia – babies B Purulent
++ Lid swelling Tetracycline eye
Chlamydia –
B Purulent
+ Signs on everted
upper lid
Tetracycline eye
ointment, or azithromyin
Chlamydia – adults U or B Purulent
+ None Tetracycline eye
Allergy – acute B Watery ++++ Minimal Marked swelling of
lids and conjunctiva
None – reassure
Allergy – chronic B Thick and stringy +
Signs on everted upper
lid. Discoloration of eye
Tetracycline eye ointment
to eye lids – REFER
Chemical U or B Watery / purulent Varies May be lid reactions Tetracycline eye
Proteases, protease activity and inflammatory molecules in tears have been found to be relevant in the pathogenesis of keratoconus. We sought to determine the influence of eye rubbing on protease expression, protease activity and concentration of inflammatory molecules in tears. Basal tears were collected from normal volunteers before and after 60 seconds of experimental eye rubbing. The total amount of matrix metalloproteinase (MMP)-13 and inflammatory molecules interleukin (IL)-6 and tumour necrosis factor (TNF)-α in the tear samples were measured using specific enzyme-linked immunosorbent assays (ELISA). Tear collagenase activity was investigated using a specific activity assay. The concentrations of MMP-13 (51.9 ± 34.3 versus 63 ± 36.8 pg/ml, p = 0.006), IL-6 (1.24 ± 0.98 versus 2.02 ± 1.52 pg/ml, p = 0.004) and TNF-α (1.16 ± 0.74 versus 1.44 ± 0.66 pg/ml, p = 0.003) were significantly increased in normal subjects after eye rubbing. The experimental eye rub did not alter significantly the collagenase activity (5.02 ± 3 versus 7.50 ± 3.90 fluorescent intensity units, p = 0.14) of tears. Eye rubbing for 60 seconds increased the level of tear MMP-13, IL-6 and TNF-α in normal study subjects. This increase in protease, protease activity and inflammatory mediators in tears after eye rubbing may be exacerbated even further during persistent and forceful eye rubbing seen in people with keratoconus and this in turn may contribute to the progression of the disease.
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