/ 11 November 2011

Seeing red serves as a warning

Red eye is a common disorder that is caused by many conditions. More often than not, the reason is harmless.

You look in the mirror one morning and staring back at you is an eye that has turned blood red. Sight is so precious to us that, understandably, any threat to our eyes causes immediate anxiety.

Red eye is a common disorder that is caused by many conditions. More often than not, the reason is harmless and the condition clears up on its own within a few days. However, it can also be a sign of something far more serious, which can lead to what many of us fear most — a real risk to our eyesight. It can also be the cause of a related underlying disorder — illness, injury or some other condition.

The two most common causes are conjunctivitis and subconjunctival haemorrhage. Conjunctivitis is an inflammation of the outermost layer of the eye and the inner surface of the eyelids. It can be caused by a bacterial or viral infection, or be the result of an allergic reaction. Viral conjunctivitis is commonly known as “pink eye” and is highly contagious.

Other than the blood vessels on the surface of the eye being enlarged and dilated, other symptoms include teary or watery eyes and some form of irritation or itchiness.

Among the first things your general practitioner will look for is that your pupils are reacting as they should and that your vision is normal.

A viral infection can often be associated with an infection of the upper respiratory tract, a sore throat or the common cold. Bacterial infection is often diagnosed with a gritty irritation and a discharge of pus from the infected eye.

This discharge often happens when you are asleep, resulting in difficulty in opening your eyes normally in the morning.

Subconjunctival haemorrhaging occurs when some of the many small blood vessels in the eye rupture. Although dramatic in appearance, and worrying when spotted for the first time, it is generally not considered serious.

But it still needs to be checked out as it could be a sign of high blood pressure. Other than some obvious eye trauma, it can also be caused by coughing, choking, vomiting or strenuous exercise. Interestingly, it is also a common disorder among divers, owing to “mask squeeze”, and fighter pilots who battle gravitational forces.

Blepharitis is a bacterial inflammation of the eyelash follicles that lie alongside the eyelids. This causes irritation and itchiness and a crust may appear.

Corneal ulcers are erosions of the cornea resulting from viral or bacterial conjunctivitis or from foreign bodies damaging the cornea; for instance, metal flakes from grinding metal without wearing safety glasses.

Far more serious is glaucoma — an eye disorder in which the optic nerve is damaged, causing irreparable harm to vision. In fact, it is a medical emergency when a sudden increase in eye pressure affects vision. Left untreated glaucoma will lead to blindness.

Signs and symptoms of glaucoma include redness of the eye, sudden pain, seeing halos around lights, nausea and vomiting, and a sudden decreased vision.

The cause of this condition is ocular hypertension, or increased pressure within the eye. It can be brought about when there is some restriction to the normal flow of blood into the eye, such as trauma, prolonged use of steroids or diabetes — or diabetic retinopathy as it is called — which can affect up to 80% of people who have had diabetes for more than 10 years.

There are many other forms of eye injury that need to be attended to before they cause real damage. Foreign objects in the eye, such as dust, sand and grit, can scratch and even cut the surface of the eye.

Damage can also be caused by chemical eye injury through acidic or alkaline substances.

And, of course, damage can be caused by poor management of contact lenses.

You only have two eyes. So use them well to identify any threats to your sight.

Eye conditions will be the topic of Bonitas House Call on November 19 at 9am on SABC2.

This article originally appeared in the Mail & Guardian newspaper as a sponsored feature.