Eyes

Our eyes are especially important organs. They enable us to see and hence to live independently of others. In the vast majority of people the eyes function so perfectly, up to middle age at least, that they are taken for granted. This is especially so in young people in the workplace who neglect to wear eye protection appropriate to their work places or particular tasks. There is still an attitude among workers that it is not macho to wear safety glasses or goggles and another among management at all levels that it is too much trouble to ensure proper eye protection is worn. Consequently, there is rarely a day goes by that we don’t have at least one patient with a work caused eye injury.

The most common injury is the embedded corneal foreign body. These are usually metallic and caused by grinding metal without wearing goggles. Sometimes they are wooden and caused by cutting wood with power saws again without wearing goggles. Many workers will wear safety glasses when performing these tasks unaware that safety glasses do not adequately protect the eyes from the showers of red hot metal particles thrown into the air from grinders or saw dust from power saws. It is not uncommon for some individuals to state they have had numerous such incidents but they continue to ignore the lessons and not protect their eyes. Little do they realise that every such incidence contributes a little more damage to their corneas.

So, at 8 am daily, there is usually at least one person sitting in the waiting room with one hand over one painful red eye that has kept them awake all night. If they have their hands over both eyes it is usually because of welding flash. After asking what has happened the first thing we do is to check the visual acuity. That is, we get them to read the eye chart on the wall first with the affected eye covered, then with the good eye covered and finally with neither eye covered. This tells us if the injury may have affected the patient’s vision and/or if the uninjured eye has a visual deficit. This information has monumental implications for the patient and serious medico-legal implications for the doctor.

It is my personal practice to then examine the eye through an old-fashioned instrument – a binocular loupe. This acts like a large magnifying glass strapped to my face to leave my hands free. In the case of a worker who had used a grinder or power saw, it will usually reveal a foreign body stuck on the cornea over the iris – the coloured part of the eye. It also enables me to determine if there is any blood behind the cornea or perforating injury to the cornea. It is also imperative to evert, (turn inside-out), the upper eyelid and ensure there is no additional foreign body stuck under there by careful examination with the loupe. Only last week a young lady presented complaining of getting “something in her eye” while gardening that day . I found a piece of grit stuck under her upper eyelid and a very large corneal ulcer. If no foreign body can be found then we are into a whole new ball game- the unilateral red eye which I will discuss later.

If a foreign body is found then it must be removed. To do so requires the use of local anaesthetic drops to make the procedure painless. Then, a gentle wipe with a cotton bud- while using the loupe or slit lamp – will sometimes suffice to remove the object. Most, however, are quite adherent to the cornea and must be removed with a needle. Obviously, this requires extreme care in optimum conditions to avoid further damage to the eye. I prefer the patient lying down on an examination couch with the height adjusted to suit me. I then work from the head end of the couch with the loupe securely in place, my left thumb and index finger holding the lids open and the patient keeping the eye still by staring at a spot on the ceiling. The needle must be held at a tangent to the cornea and the tip used to dislodge the object which usually comes away in bits especially if it is metallic and has rusted. (Ferrous metals will begin to rust within hours of contacting the eye.)

Sometimes that is all that is required. However, if ferrous metal has been in the eye overnight then a rust ring will have formed and this must be removed. It can be done with a needle but a better result is obtained by using a fine dental drill burr in a small, battery operated tool - and extreme care. Some doctors are unwilling to use this instrument for fear of perforating the cornea – a catastrophe if it does occur. But, with careful technique and bearing in mind the cornea is of about the same hardness as the thumbnail, success can be readily achieved.

At this stage it is smart to instill some fluorescene into the eye and examine through a slit lamp using a blue light. Fluorescene is yellow in colour and gets taken up by damaged cornea and fluoresces bright green under a blue light. This will reveal the size of the area damaged by the foreign body, and its removal, and any other areas of cornea that may have been damaged by foreign body or its removal. Penultimately, the visual acuity must be again assessed to ensure the procedure has not resulted in any further damage to the eye. This has major medico-legal implications.

The ultimate and, arguably, the most important part of the process is to correctly apply a double pad to the affected eye. This is because the cornea is a bit like Perspex covered with a very thin layer of cells about six cells thick and these cover the nerve endings. The removal of the foreign body inevitably results in the removal of the entire layer of these cells and exposes the nerve endings. If the eye is not padded then, every time the patient blinks, the eyelids wipe away the new cells trying to grow across the wound – which we call an ulcer. A gauze eye pad is folded in half and placed into the eye socket with the folded edge parallel with the eyebrow. Then a second pad is placed over the first and secured into place with several narrow strips of light adhesive tape. This must hold the eyelids closed without the patient making a conscious effort. I advise this is left in place until the patient switches off the light to sleep that night. The ulcer will heal within twelve to eighteen hours.

It is also important to advise the patient that, with the eye pad in place the visual field is reduced by about half and, if driving, hazards may not be seen on the affected side – this included kids on bikes or foot or vehicles at intersections etc. Further, with only one functional eye, depth of field cannot be judged with the same resultant hazards when driving and even when reaching for a cup of hot coffee, (or cold beer), it is likely to be knocked over because the patient cannot accurately judge how far away it is.

That entire process only takes about ten minutes to run through. Patients so treated rarely need follow up but those who do not have the pads applied, or who remove them, will almost always return next day with a painful, red eye due to an unhealed ulcer. It seems this is not taught to medical students or young doctors these days. I am for ever seeing these patients, treated by other doctors, returning next day with unhealed ulcers.

While we are on the industrial scene I should mention welding flash. This is an extremely painful result of exposure to the intense ultra-violet radiation emitted from the welding arc. The UV destroys most or all of that thin layer of cells covering the cornea thus exposing the nerve endings. The dead cells must be replaced by new cells growing from the edge of the cornea. This is relatively easily achieved by padding the eyes, after using local anaesthetic, for twelve to eighteen hours. The condition is less common among welders than among people passing by in the workshop or idly watching welding in progress.

Penetrating eye injuries are not common, fortunately, but are a real emergency situation. Kids run into plants like grass trees, Bougainvillea or roses and the thorns can penetrate the eye. Tradesmen hammering cold chisels or drifts with burred heads can have steel splinters penetrate the eye. Thrown objects like darts, sticks, nails and glass may do the same. We tend not to muck about with them but send them for eye specialist treatment immediately. The old saying we chanted as kids, “Sticks and stones may break my bones but names will never hurt me.” Could well be modified to, “Sticks and stones may break my bones … and make a hell of a mess of my eyes, too.”

Chemical burns to eyes are always serious. Common causes are oven cleaner, battery acid and detergents accidentally splashed into one or both eyes. Oven cleaner is very serious as it consists mainly of caustic soda, (sodium hydroxide), an extremely alkaline chemical which tends to soak into human tissues then destroy them. Oven cleaner in the eyes is a real emergency and the key to successful management is the immediate first aid – getting the eye, or any other part of the body contacted – under running water. The shower is best but any tap will do. The eyelids will go into spasm with first contact of the caustic and must be forced open to allow the water to run over the eyeball. This must be maintained for, at very least, twenty minutes or more if possible. Then medical attention is mandatory and transport is best by ambulance.

Caustic in contact with the eye will often turn the cornea opaque. This is irreversible and the patient will require a corneal transplant. It can also penetrate into the iris, sclera and other parts of the eye often causing total blindness in the eye. Anyone using oven cleaner, or any other chemical, should protect their eyes by wearing goggles. Glasses, even safety glasses, are not adequate.

The same principles apply for the use of and treatment of any chemical contact including the eyes. Battery acid is sulphuric acid and extremely damaging to human tissue. Spirits of salts is hydrochloric acid and almost as strong as sulphuric. Fluoric acid is the strongest possible and contact with even small amounts can be fatal as a consequence of burns and of the effects upon the chemical balance within the body.

Wet cement is very alkaline. It contains lime which, when dissolved in water, forms calcium oxide which is extremely alkaline. It is very difficult to remove cement from the eyes and, as long as it is there, it continues to burn the eye. Urgent treatment by an ophthalmologist – eye specialist - is mandatory. We had such a patient recently. He worked on a building site and hearing someone shout some levels above him he looked up just in time for a large blob of wet cement render to fall into his right eye. He was not wearing any eye protection. The force of the cement striking his eye was probably enough to do considerable damage but the alkaline burns were worse.

His eye was flushed with water on site then he was taken to a doctor’s surgery where a morphine injection was given and local anaesthetic drops were instilled onto the eye. He was immediately sent on to us. On arrival half of his right cornea was opaque and there was a large lump of hard cement stuck to the eyeball adjacent to the cornea and extending under both eyelids. We placed a pad over the eye after instilling more anaesthetic and I arranged for his immediate transfer to a teaching hospital and spoke to their duty ophthalmologist. As usual, we received no feedback but I cannot help but conclude that the unfortunate chap would lose much, if not all, of the sight in is right eye. An injury entirely preventable by wearing at least safety glasses.

Occasionally someone, usually a woman, turns up after splashing detergent into the eyes. Provided it is simple kitchen or Washing detergent it isn’t too much of a problem. (After all, shampoo is simply a detergent, with the odd miracle substance added, and we often get it into our eyes.) It can irritate a bit and cause temporary dryness of the eyes because it disrupts the tear film – which is not just a film of water but a complex triple layered film of precisely arranged fats, water and mucin. Treatment consists simply of irrigating the eye with water then using artificial tears for a day or so.

But detergents ain’t just detergents. There are some that contain other chemicals added for specific purposes. An example is some of those made for use in dish washers. Some of these have strong alkaline substances added and this will cause severe eye damage as discussed above. A simple rule of thumb is that anything that gets into the eye and causes pain required immediate medical attention.

Like thousands of other Australian, many of whom seek relief in the ED, I suffer dreadfully with allergic conjunctivitis in early winter and spring. It is simply irritation of the eyes caused by allergenic substances in the air. The winter attacks are caused by spores from mushrooms and other fungi that flourish with the first rains. The spring, or vernal, conjunctivitis is caused by pollens from flowers and crops. These allergens are picked up by prevailing winds and deposited on the eye of the poor, suffering thousands of sensitive victims. These allergens trigger a reaction by the human immune system. The conjunctiva becomes red, intensely itchy and may even become swollen and look like a lump of jelly on the eye. This alarming condition is known to us as chemosis.

My own eye doctor, (ophthalmologist), advises me to not use antihistamine eye drops. He prefers that I flood the itchy eyes with simple, lubricating eye drops. This, he says, will wash the pollens and spores away. Yair, well, sometimes it does and sometimes it doesn’t. When it doesn’t I am compelled to use the antihistamine drops. I offer my ED patients the same advice but, if they come in with chemosis I use the antihistamine drops up front.

The most common eye infection is conjunctivitis caused by bacteria although some viruses also cause it. It is usually bilateral – in both eyes – and produces pus which causes the lids to be stuck together on waking in the morning. It is very distressing and interferes greatly with vision. When I was a kid it was much more common than today and we called it sandy blight – probably because it felt like sand in the eyes.

Treatment is simply antibiotic ointment applied at least half hourly during the first day and hourly on the second day. (Viral conjunctivitis requires special antiviral ointments.) This is easily achieved by pulling down the lower eye lid and squirting about half a centimeter of ointment in behind it. It makes vision more blurred and things a bit mucky for a while but it works. In my most humble opinion antibiotic eye drops are useless – they stay in the eye for less than three minutes before being flushed down the tear duct into the nose. They aren’t much use there. The ointment will hang around on the conjunctiva – where the germs are – for about twenty minutes. And I always advise the victim that personal hygiene is critical to prevent others catching it. Strict use of only their own towel and face washer is imperative.

There are other, far more serious, eye infections. We tend not to intervene with these but send them off to an ophthalmologist. Shingles, by the way, can infect the eye. Shingles is caused by the chicken pox virus that lays dormant in the spinal cord after causing the disease in childhood. Then, usually when the victim is stressed physically or emotionally it flares up and tacks down the nerve to the skin where it causes a very painful rash. It can track into an eye – it almost invariably attacks only one side of the head or body – and it can cause blindness but, these days, treatment is available and is very effective if commenced within 72 hours of onset of symptoms.

Glaucoma is a condition caused by abnormally high pressure within the yes. It is usually due to an imbalance between the production and the drainage of the fluid that fills the eyes. Too much accumulates in the eye and the pressure increases. There are two types the most severe being of sudden onset and usually quite painful. It can threaten blindness in a short period of time. The other is of gradual onset and less threatening if properly treated and monitored. The definitive diagnosis is made using an instrument called a tonometer – it measures the pressure inside the eyes. We don’t see a lot of glaucoma in ED but it is a condition we must always bear in mind when diagnosing eye problems.

I did mention earlier the unilateral red eye. That is one eye being red and, usually painful with or without visual disturbance. There are several serious, sight threatening conditions that can cause a unilateral red eye and there are several less serious conditions causing the same symptoms. It is our responsibility to make an accurate diagnosis. Failure to do so can cost the patient their vision in at least one eye. We also need to be on our guard for detachment of the retina and of eye symptoms presenting as indicators of other afflictions such as strokes, brain tumours etc. Diabetes and high blood pressure can cause changes in the retina that we can see with proper use of the ophthalmoscope. The eye is a window through which we can look into the body.

And, finally, there is the contact lens. The invention and introduction of contact lenses was a giant leap forward in ophthalmology as measured by the popularity of the devices. Yet they are not without their problems and the emergency department is often used to solve the common problem of missing lenses – usually late at night.

Most people, rightly, remove their contact lenses before going to bed. They run into trouble when they can’t remove one, or both, lenses. Often, but certainly not always, befuddled by the effects of alcohol or other drugs the poor patient might get one lens out without difficulty but then spend hours trying to remove the other without success. At some stage they give up and get themselves to the ED. In the vast majority of such cases we do not find the lens. This is because it was, either, not inserted in the first place or was removed and forgotten. Some people present frantically concerned that the lens has slipped around behind the eye. Contact lenses cannot do that.

After a thorough examination most such patients accept that the lens is not in the eye. Occasionally considerable persuasion is required - especially with the inebriated. All are advised to return in the morning if their eye remains red or painful or there is visual disturbance.