Unpleasant and contagious ‘pink eye’ looks worse than it usually is

IN October, something happened in Pakistan that prompted the closure of 56,000 schools for four days.

It wasn’t covid nor was it related to some sort of natural disaster. In this instance, millions of students were sent home because of an outbreak of conjunctivitis.

Now one could be forgiven for being slightly taken aback by this — after all, conjunctivitis is widely regarded to be quite a common but relatively mild condition.

Indeed it’s thought that one per cent of GP appointments in the UK are related to this simple eye infection and there is certainly no advice for sufferers to stay home from school.

As such, it’s not the sort of thing that one would normally associate with mass school closures.

But there are, on occasion, epidemics of conjunctivitis that require more dramatic measures.

In Ghana, as another example, there are regular seasonal spikes of a particularly contagious form of conjunctivitis referred to as Apollo disease, so named because the first epidemic coincided with the Apollo 11 moon landings.

The trouble with conjunctivitis is just how contagious it can be. Although long-term effects are very rare, in the interim it can be quite troublesome.

The conjunctiva of the eye is the clear thin membrane that covers the white surface of the eye (the sclera) and also the inner surface of the eyelids. Its name comes from the Latin “to join”, which is less literal than many other medical terms.

Given that its main role is to protect the surface of the eye, one might argue that another name may have been more appropriate but conjunctiva is the one that has stuck.

The membrane itself has a thickness of about 10 microns (one micron is one thousandth of a millimetre) and yet it still finds enough room to host a network of tiny blood vessels that supply the surface of the eye.

When the conjunctiva becomes infected, it is the dilation (expansion) of these vessels that gives the characteristic red appearance, hence the reason conjunctivitis is sometimes referred to as “pink eye”.

As these vessels dilate, they leak inflammatory fluid and cause watering of the eye. This discharge can accumulate at the edges of the lids and give that sticky appearance — something that tends to be more prominent in the mornings after having had your eyes closed all night.

This inflammatory process can be in response to an allergen such as pollen and in such cases is called an allergic conjunctivitis.

Although technically an inflammation of the conjunctiva can also be due to a foreign body or trauma to the eye, the term conjunctivitis is more commonly associated with infection with a virus or bacterium.

Viruses account for about 80 per cent of infectious conjunctivitis while bacteria make up the rest.

While the condition is often linked to children, it is something to which people of all ages are susceptible but, because of the tendency for little fingers to rub little eyes, it tends to spread in younger age groups more easily.

Bacterial conjunctivitis is slightly more common in children but clinically telling the difference between viral and bacterial is very difficult.

There is perhaps more likelihood that the eye might have more discharge and stickiness in the bacterial form but this can happen with a viral cause too.

Ultimately, whatever the underlying cause is, the infection will most likely be self-limiting so often the best approach for a conjunctivitis is to remove any discharge by bathing the eye with cotton wool dipped in sterile saline or boiled water that has been allowed to cool.

As the name would suggest, an antibacterial eye drop or ointment does not work on viruses but may do on bacteria.

Chloramphenicol is an antibiotic that was first derived from a soil bacterium called streptomyces venezuelae in the Forties. It was one of the first synthetic antibiotics to be mass-produced and has been used orally and intravenously for serious infections such as cholera, typhoid and even plague.

Taken in this way, it can have some nasty side effects and has since been surpassed by other safer antibiotics. It has, however, found its niche in eyes and these days it tends to be the gold standard in antibacterial drops used in conjunctivitis.

It has been available over the counter since 2005, meaning people don’t need to go to the GP for a prescription.

While chloramphenicol drops certainly have a role to play in treating severe and stubborn cases (which very rarely can lead to more permanent damage to the eye), in most cases bacterial conjunctivitis gets better on its own after five to seven days.

Its liberal use by pharmacists and GPs alike contributes to the ever-growing issue of antibiotics resistance and so, considering all of the above, wherever possible the infection should be given the chance to get better on its own.

If you wear contact lenses and develop conjunctivitis, it is best to get your GP to stain the eye and make sure there has been no damage or ulceration to the cornea, which is the outside of the eye covering the pupil and iris areas.

This is done with a fluorescent substance called fluorescein and shining a UV light at the eye which should show up any damage.

During a case of conjunctivitis, it is really important to avoid putting lenses in to prevent this damage from happening.

It is important to note that conjunctivitis is not the only thing that can cause the whites of the eyes to go red.

If you experience a red eye associated with pain in the eye itself, sensitivity to light or trouble with your vision (either persistent blurring or double vision), there is a chance some of the structures deeper in the eye might be the source of the problem, which certainly warrants a check with your GP who may even suggest a visit to eye casualty.

Likewise if there is any suggestion that the herpes virus is involved or if a newborn (within 30 days old) baby develops severe gunkiness in the eye, this also requires a check with a doctor.

Although rare, chlamydia or gonorrhoea can cause conjunctivitis and this tends to be more severe, requiring closer attention and early treatment with antibiotics.

Having said all of that, on the whole conjunctivitis remains one of the milder ailments from which we suffer.

Unpleasant, contagious and rather unsightly, it should eventually settle and, providing you “keep an eye out” for the red flags I’ve mentioned, it should be gone within a couple of weeks.