Cuts of the eye and first aid tips

Corneal lacerations-cuts to the eyeball

Mr L, a trainee carpenter, was trying to remove a nail from a piece of wood. He was thinking of getting off early that day, because of a date that evening to celebrate his girlfriend's birthday. As he levered the nail with the claw of the hammer, he suddenly felt it give and the nail flew off, straight into his eye.

The cornea is the clear window at the front of the eye. It is also the part of the eye closest to the object being looked at. 

Being constantly exposed to the environment, corneal injuries are a fairly common problem. They range from foreign bodies such as metallic particles from drilling or welding work, to abrasions/scratches, lacerations and chemical injuries.

Corneal lacerations occur when a sharp object cuts or pokes the cornea. They may be partial thickness, or they may go through the full thickness of the cornea and affect the inner parts of the eyeball.

Apart from direct damage to the eye, corneal lacerations are serious injuries which may also damage the eye by causing an infection, or impair vision because of corneal scarring after the eye heals.

Causes of lacerations

Common causes include flying objects, which may happen, for example with a nail as above or while cutting grass with an uncovered mower and while drilling and hammering. Broken glass from road traffic accidents are also a notorious cause of lacerations.

At the time of injury, a severe sharp pain will be felt as the cornea is one of the most sensitive parts of the body. There is almost always a clear history of a foreign object cutting or flying into the eye.

After the injury, vison is commonly blurred, especially if the laceration is deep and close to the centre of the cornea. There may be increased sensitivity to light, tearing, and it may be difficult to open the eye.

What the doctor will do to examine the eye

The doctor will usually instil some local anaesthetic eyedrops first to numb the eye and allow comfortable examination. Usually a careful examination on a slit lamp microscope then follows, with the doctor determining whether there are any remaining foreign bodies, and also very importantly, the depth of the laceration. If the cornea suffered a full thickness cut, fluid may leak from inside the eye, or internal parts of the eye such as the iris may protrude outwards.

A full thickness laceration has occurred in the centre of Mr L's eye. The nail penetrated the cornea, and also the lens of the eye, which has become a trauma induced cataract. Fine black nylon stitches were used to close the laceration.

Treatment of corneal lacerations

First aid for suspected corneal lacerations

• ·         Do not attempt to remove any foreign bodies or what appear to be foreign bodies/dirt (protruding parts of the eye may look like foreign bodies or dirt)
• ·         Do not wash or press on the eye
• ·         If possible, obtain an eye shield or fashion one from a plastic cup. This is easily done by cutting the cup around the rim about 1-2cm from the bottom, so that the cup now only has a shallow rim. (see below)
• ·         This can be taped so that the rim rests on the bony edges of the eyebrow and cheek.
• ·         Send the patient straight to a specialist eye clinic or the emergency department.

Cuts of the cornea require different types of treatment, depending on how long or large they are, and even more importantly, whether the eye is penetrated.

If the cut is small and only affects a partial thickness of the cornea, it is treated like a corneal scratch or abrasion. Usually, this type of injury heals well with some antibiotic eyedrops to prevent infection, and the removal of any remaining foreign bodies. A bandage contact lens is sometimes used to protect a long shelving laceration.

For a corneal laceration that cuts through the full thickness of the cornea, the situation is more complicated. Usually, the first step, which is performed by the eye surgeon in an operating theatre, is to clean the wound and to stitch up the cornea so that there is no longer any fluid leakage from the eye. If there is internal tissue protruding from the eye, this is carefully repositioned into the eye when possible. Where there is more extensive damage such as lens damage causing a cataract, this may be dealt with at a second stage when tests are done to allow selection of the most suitable lens implant for the patient.

Mr L had his corneal laceration stitched up, followed by a cataract removal operation and lens implant. He now has good vision in that eye, however, due to the cataract surgery now has 'presbyopia' in that eye because the lens implant cannot autofocus like his original lens could before.

Prevention of corneal lacerations

·      These injuries can be prevented by wearing protective eyewear when engaging in activities such as grass cutting, hammering or drilling.

Corneal lacerations are potentially very serious injuries of the eye. Besides possible internal eye injuries, infections can also occur and lead to impaired vision. Do take care and use safety eyewear when engaging in hazardous activities, as the old adage ‘prevention is better than the cure’ certainly holds true here.