Squamous Cell Carcinoma
This is the most common cancer of the eye. It occurs commonly on the
,
conjunctiva, cornea, eyelids or involve the bony orbit.
Horses predisposed include older horses, those with
around the
eyelids, and those exposed to UV light.
The tumor may appear as a pink raised roughened mass. On the eyelids they often appear as ulcerated sores. It is common for the tumor to spread to both local & distant tissues. Treatment will depend on the size & location. Small tumors of the 3 rd eyelid, conjunctiva or cornea are the easiest to treat and most successful with local surgery. Tumors of the eyelid or orbit are less successful and often require removal of the eye.
Retinal Diseases
The most common retinal diseases include:
, therefore night vision is affected. Day vision is unaffected. Occurs more commonly in Appaloosas. Severe vitamin deficiency is linked with causing night blindness. – defect in the Chorioretinitis – inflammation of the retina, followed by scarring & destruction of retinal tissue. The optic nerve is most often involved as well. Commonly caused by ERU and linked with poising. Retinal – the retina becomes partially or completely detached from the back of the eye. Uveitis, chorioretinitis or severe head trauma can cause detachment. Usually results in and complete blindness.
Anterior Segment Dysgenesis (ASD)
ASD is a congenital ophthalmic abnormality seen in coat colour with flaxen mane & tail. This colour is often seen in Rocky Mountains, Kentucky Mountains & Miniatures. Horses with ASD, the front part of the eye doesn’t develop correctly and sometimes the back of the eye can be affected as well.
and lesions are the common signs and symptoms. Some animals suffer no loss of
vision, some are born blind and others will go blind later in life.
Treatment is cataract surgery.
417
Made with FlippingBook Publishing Software