Saving The Eye
Recognition and Treatment of Eye Injuries
To continue with our series on the eye, we will discuss injuries and their management. With eye injuries it is very important an examination be made and treatment started quickly. An injury to the clear part of the eye causes changes just like an injury to the skin. At first there will be swelling followed by attempted remodeling of the involved tissue. In the eye however, there is no circulation to provide the all-important blood cells to clean up bacteria and fight infection. With swelling of the tight outer surface of the eye there is separation of the tissue layers causing even more damage done to the cornea and creating an excellent place for infection. Once started, there is little to prevent the infection from spreading throughout the eye tissue and destroying it. As the tissue is destroyed it changes into a slimy substance that looks like mucous, and will almost drip off the eye.
Without treatment, in an amazingly short time the area around the injury can give way, allowing the fluid within the front chamber to escape. As this fluid escapes, the force of the fluid from the larger back chamber pushes the lens into the break. This leads to a protrusion or "nipple" on the surface of the eye that, hopefully, only a few of you have seen. Once this occurs the lens is useless, the eye cannot focus. Unfortunately the lens movement also indicates the more serious problem of rupture of the eye.
When presented with a rupture of the eye, it is our objective to repair the ‘hole’ to prevent the continued escape of fluid. We do this by suturing the edges together if the hole is small. Counter pressure is very important to prevent the fluid within from forcing its way through the stitches. The third eyelid is brought up over the eye and sutured. Its inner surface provides a smooth, firm surface for the eye to contact. If we are successful and there is not any other damage, the eye will heal and refill. Unfortunately, if the injury goes for some time before treatment there may be other damage to the eye. The most common is closure of the tiny drainage hole that allows fluid to escape from the front chamber.
Fluid is continually produced within a healthy eye to maintain a constant pressure within. To prevent the pressure from becoming too great, a little fluid is constantly released thru the very tiny hole in the front corner of the cornea. This can be closed off if the eye swells in response to the injury, or infection following the injury. The uncontrolled build up of pressure is not only terribly painful, but also prevents healing and destroys tissue over the surface. Eventually the surface tissue gives way and the eye shrinks from the uncontrolled loss of fluid. This is the end of the eye.
This is a terrible story and before you become to depressed I would like to emphasize most eye injuries are not this serious. The time we devoted to explaining the above is warranted: to impress on the horse owner how important prompt examination and treatment is to the successful recovery from eyes injuries.
If the eyelids, are closed and there is tearing, you can be sure the eye has been injured. It is up to us to determine how bad the injury is. It may require a local anesthetic or even tranquilization to convince Dobbin to let us open the lids and see the eye. With a blow to the eye, or if the eye is scratched, the conjunctiva (the white tissue) may be swollen. An early injury may not be apparent on the surface of the eye. We put a stain in the eye that will only be absorbed by the broken tissue. If there is a break in the surface, the stain will be absorbed and show up very well when a light is shined on the eye. We can tell by this the extent of the injury and what treatment we are going to use. More on this next week.
CLICK BELOW TO DISPLAY A PRINTER-FRIENDLY COPY OF THIS ARTICLE
Select "Open this file from its current location," if you just want to print it out,
it will open in a simple word processing application, select the print button.
(unless you want to save this article in your computer's memory)
