Corneal injuries are frequently seen in pets. The injury can be mild to severe, but almost every case is very painful, especially when obtained suddenly. The cornea is the clear membrane at the front of the eye, surrounded by the sclera or “whites” of the eyes. There is normally no blood flow to the cornea; rather the cells that make up this unique membrane are supplied nutrients and oxygen exclusively through the tear film.
Trauma to the cornea is frequently a result of dogs diving into brush, rose bushes or pesting the household cat loaded with a full set of claws. The cornea can also be damaged when splinters, construction debris, or plant material get lodged in the eye.
Typically the trauma results in immediate pain, squinting and tearing regardless of the depth of the injury. An owner may notice a white to blushish haze or cloudiness on the surface of the cornea, and the sclera may appear red. All corneal injuries should be seen promptly by a veterinarian. Your veterinarian will apply a special stain called flourscein to the cornea to highlight the damaged area. An intact smooth cornea will not retain stain, but a scratched or abraided cornea will hold the stain and show a green color.
Fortunately the cornea has an amazing and rapid ability to heal in most cases. A small corneal scratch will typically heal in 3 to 5 days. Regardless of how small corneal scratch is, these lesions need to be treated with topical antibiotics. A small scratch on the cornea could cause complete loss of the eye if it were to become infected. The topical antibiotics also help to lubricate the eye, and therefore, can be soothing.
A deeper cut into the cornea or a cornea with multiple areas of trauma is at an even greater risk of infection and can cause inflammation of the inner eye. This condition is called uveitis. When uveitis develops, the iris, or colored part of the inner eye surrounding the pupil, can become swollen and tight. The pupil will appear very small, and frequently, the fluid in the front chamber of the eye becomes cloudy. If this condition is not treated promptly, permanent damage to the iris can occur. To treat uveitis, medications can be used to relax the iris, widen the pupil and increase the comfort of the eye.
Finally, full thickness punctures or cuts (lacerations) of the cornea can occur and are very serious. This is always an emergency situation and even with the most prompt and specialized care, and eye cannot always be saved. A puncture wound can “inject” bacteria into the eye and set up a difficult-to-treat infection. If the puncture is large enough, ocular fluid can leak out of the eye and frequently parts of the iris will be “sucked” into the wound and become adhesed to the cornea.
Lacerations of the cornea can sometimes be repaired and fluid restored, but the cut requires specialized suture, magnification, and a very steady handed surgeon. Again, infection must also be battled.
There are many other ways a pet can develop corneal trauma including low tear production, chemical burns, entropian (inward curling of the eyelid margin) and abnormally placed hairs. These specific topics may be covered in future issues of the Doberman Dispatch.
© 2001 Carla Douple, DVM. All rights reserved. For permission to reprint contact author at Landisville Animal Hospital, 3035 Harrisburg Pike, Landisville, PA 17538
by Carla Douple, DVM
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