Eye burn

definition

The damage to structures of the eye caused by various chemical substances is referred to as chemical burns.
Depending on the duration of exposure, strength and type of chemical, chemical burns of different strengths can occur, which can be divided into several stages.

In any case, the chemical burn of the eye is an acute emergency which requires immediate first aid measures directly at the scene of the accident and medical treatment.
The affected eye must be rinsed out immediately, as eye burns can lead to serious damage such as blindness or loss of the eye.

Causes of an eye burn

Chemical burns to the eyes can be caused by contact with Acids or Bases arise.

Acid burns can e.g. by liquids from the chemical industry, car batteries and acids in household and job caused.
Bases are in Detergents and also in lime.

Also Adhesives can cause chemical burns.

Most burns occur while handling harmful substances WorkplaceHowever, eye burns can also occur during leisure time.
The majority of patients are young people who suffer from chemical burns in the course of accidents at home or at work. Furthermore, attacks with acids and alkalis are also a reason for chemical burns on the eyes.

Depending on which acid or alkali gets into the eye, the process of chemical burns takes place at different speeds.

Acids and bases both lead to the breakdown of the external structures of the eye. They do this through different mechanisms of action.

Together with the Burns make the burns a share of approx. 8-18% of all eye injuries out.

Pathophysiology

The Bases cause the hydroxyl ions (OH ions) to damage Cell membranes and thereby to the destruction of the affected cells. Furthermore, the cationic (positively charged) portion of the base destroys epithelium (superficial protective cell layer) the Cornea and Conjunctiva (Conjunctiva), as well as the supporting one Connective tissue, initiated.

It means that all external cell layers of the eye attacked and destroyed - there is a liquefaction of the protective outer cell layers (Colliquational necrosis).
As a result, the base ultimately also gets into the inner areas of the eye. Here the increases PH value due to the penetrated OH ions. This ultimately leads to the destruction of the deeper structures of the eye: the Ciliary body, iris and lens.

Acids act through H + ions (Protons). These lead to natural Proteins of the eye lose their original function and structure (conformation). This process is called Denaturation designated. Due to the loss of function of the proteins, the cell in the eye also loses its function.

The cells and proteins go under and form an association of interconnected and clumping cell debris, what is called Coagulation necrosis referred to as . As a result of this clumping, a kind of new protective barrier is formed, which prevents the acid from penetrating deeper layers and causing damage.

Therefore cause weak to medium strong acids rather superficial damage. Strong acids, however, overcome the barrier that has formed Coagulation necrosis and also attack deeper parts of the eye.

Symptoms

Kick if the eye is burned Pain in and around the eye on. Depending on how extensive the chemical burn took place, the area around the eyes can also be affected (facial skin, eyelids).

To speed up the washing out of the irritant, the eye begins to water as a protective measure.

Within a very short time the cornea can become cloudy due to the destruction of the cells and Vision loss to lead (Decreased vision).

This can be up to Blindness of the eye to lead. A whitish clouding of the eye can be seen.

It can also become a spasmodic closure of the eyelids come.

In the case of more severe burns, there is a possibility that the patient will fall into one as a reaction to the injury and the pain State of shock falls.

therapy

That is particularly important prompt treatment the eye burn directly at the scene of the accident in order to improve the course and the later chances of recovery.

These should be carried out by those present without waiting for the doctor. Even during the first aid measures should called a doctor or be on your way to an ophthalmological practice.

The eye must be rinsed out immediately. The eye should be rinsed with liquid for at least 15 minutes. In the best case, the eyewash is not interrupted until a doctor is present.

The basic rule here is that it is better to immediately rinse with liquid than to rinse with distilled water after a long waiting period.
Of course, it also applies here that polluted water should not be used.

The victim's head is tilted to the side of the eye burn so that the uninjured eye cannot come into contact with the corrosive substance.
For the then following Eye wash must the eyelids held open against the resistance of the eyelid cramp become.
The rinsing liquid is then poured into the eye from a height of about 10 cm. All neutral liquids in the vicinity are suitable as a liquid for rinsing the eye.
While the liquid is being rinsed into the eye, the patient has to step in all directions look so that the rinsing liquid gets into every corner of the eye.

The first aid provider should also inspect all corners of the eye and look under the eyelids. Often, in the course of chemical burns and the subsequent processes, such as the reaction of mortar with water, solid body which can lead to further damage if left on and in the eye.

If a person has got mortar, cement or other calcareous substances in their eyes, water must never be used as a rinsing liquid! In this case, a doctor must be consulted immediately.

Water is best (Mineral water or tap water) or also Buffer solution.
In the workplace, where dangerous substances are often handled, there is often a so-called Eye wash.

In an emergency and in the absence of the above options, others can also aqueous substancessuch as lemonade, beer, lukewarm or cold tea or coffee can be used for washing up.
On the other hand, milk is unsuitable, as they can increase the chemical burn damage in the eye.

Should still Limestone in mind, these will be with a at best damp cotton swab carefully removed. Right on the Cornea (the transparent part of the front of the eye) this should be avoided.

A local anesthetic, if present, can be dripped into the eye at shorter intervals during the rinse to relieve pain.

After thorough rinsing, the patient must go to one immediately Ophthalmologist or at best in one Eye clinic to be brought. On the way there should be the eye continually rinsed become. The eye is also rinsed at the ophthalmologist's office, for which purpose medical solutions are used.

The ophthalmologist examines the eyes and assesses the extent of the damage. Any existing Lime chips away.

As an acute therapy, drops are placed in the eyes at short intervals. Especially Antibiotics, Vitamin C drops and Cortisone are administered.
In the case of severe burns, additional Eyeruff given to dilate the pupil. Vitamin C and cortisone are often considered in addition Tablets or infusion prescribed.

The rinses are repeated at certain time intervals. The doctor also determines how long therapy must be continued.

Irrigation solution

In science today, various detergents are discussed in terms of their advantages and disadvantages.
A fundamental problem in the choice of detergent is the question of which one Osmolarity it compared to the Tear and ventricular fluid should have.

The problem with using regular water is that it contains fewer dissolved particles than the liquid inside the eye. The water diffuses wherever one higher concentration of particles is present to compensate for the concentration difference.

So when using water as a detergent on a damaged Cornea is given, then this water penetrates through the open areas of the cornea into the deeper areas of the eye and could cause a possibly already existing water retention (edema) amplify.
This makes it easier for the corrosive chemical to get to other parts of the inner eye.

Accordingly, in many places nowadays there is a compared to eye wash hypertonic (more dissolved parts) liquid used.
This prevents the water from penetrating through the damaged cornea. It is hoped that a flow of water and ions through the cornea out of the eye will be induced and the caustic ions of the chemical will be released and not penetrate deeper.

Staging

The categorization of chemical burns in the eye is made into four stages. The classification is based on the Strength and depth of the injury, as well as the expected forecast.

stage I and II rather indicate minor and superficial injuries. You make your way through a Hyperemia (excessive blood supply to the affected area due to dilated vessels), as well as a Chemosis (Edema of the Conjunctiva, Fluid retention in the tissue).
Furthermore, minor erosions are the Cornea visible. These are crater-like injuries to the cornea, caused by the chemical.
The epithelium often takes on a lighter grayish-glassy color.

The stages III and IV denote more severe burns, the one larger area and especially deeper layers affect the eye.
In contrast to the slight damage, stages III and IV do not show hyperemia, but rather one Lack of blood circulation (Ischemia). Often found in the vessels Thrombi (Clumping of blood platelets) that can block the blood vessels.

The damage to the superficial and deeper parts of the eye also causes changes Iris and lens instead of. Find it Discoloration of the iris and a persistent Lens opacity instead of.
There are also Necrosis (Areas with dead cells) in the area of ​​the Conjunctiva.

The injury or inflammation can include involvement of the anterior chamber of the eye. This imagines Exudate (Fluid with inflammatory cells, pus).

Consequential damage

Depending on how caustic the substance was, it can be too no damage at all from slight to severe changes to the most serious consequences up to blindness come.

Generally are Caustic burns clear heavier as Acid burns, as they can penetrate deeper into the eye.

In the case of slight burns, no or only slight, superficial damage to the cornea occurs. The blood flow to the Conjunctiva is then intact and consequential damage is not to be expected.
Moderate to severe burns, however, can become large Corneal abrasion to lead. The cornea can also be clouded (possibly permanently). A Reduced blood flow parts of the conjunctiva is possible. Sometimes the conjunctiva also sticks eyeball and eyelid together (Symblepharon).

An extremely severe chemical burn leads to the complete loss of the corneal surface and the conjunctiva at the edge of the cornea. There is no longer any blood flow and the cornea is completely clouded. It forms Conjunctival adhesions (Symblepharon) and caustic burns in particular can also damage the inside of the eyes (lens, Iris, Increase in intraocular pressure).
Blindness is possible.

Follow-up

If the first aid measures have been carried out and a doctor has been consulted, further treatment can be given.

The use of Antibiotics is important to prevent further infections in the injured eye. The exact examination of the eye by the doctor is relevant to assess the stage of the burn.

Should be higher stage present, i.e. a deeper injury with necrotic areas, must often surgically be treated. So it has to be surgical removal of the destroyed tissue be performed.
This can be done in Local anesthesia, but also in general anesthetic respectively.

In the event of major damage, a Transplant on the eye be performed. That means that the Cornea or the Conjunctiva is restored by other tissue.

A principle that has been used for a long time is Amniotic membrane transplant. Placental tissue (uterine lining cells that divide very well) is applied to the areas where the necroses have been removed.
The idea behind this is that new epithelium (superficial protective cell layer) develops better and inflammation and pain are reduced.

A newer method is that Tenon sculpture, in which functional connective tissue (intermediate and supporting tissue) is placed from the eye onto the surface of the eye and attached in the depth of the eye.
It could be observed that there was less frequent necrosis in the area of ​​the anterior eyeball (Bulbus oculi).
A However, complete regeneration of corneal epithelium rarely occurs, which is why the use of a donor or artificial cornea is necessary.

The use of a corneal transplant is generally relevant if the chemical burn causes a irreversible clouding of the cornea has taken place.

forecast

The prognosis depends on the severity of the burn. The easier the burn, the fewer deep structures are affected and the less the cornea and conjunctiva are injured, the better the prognosis for complete healing.

It is important that in each case a Eye wash takes place. If this is done on time and sufficiently, the prognosis for the further course can be better.

In principle, the Stages I and II as prognostically good. They rarely require further invasive techniques and often heal in less time. You should definitely have one medical check take place as the damage could also worsen.

Chemical burns of the Stages III and IV have a worse prognosis for extensive injuries to deeper structures of the eye. Parts of the The cornea, conjunctiva and the lens may need to be removed and replaced with grafts.
Through various transplants, partial or complete preservation of vision can be achieved, albeit with limited vision.