Feline corneal sequestra can be dramatic in appearance and are unique to domestic cats. Sequestra refer to the development of a dark to black plaque on the cornea which is a dead piece of corneal tissue. This plaque is usually oval to round, but they can vary in shape and size as well as depth in corneal tissue. Some pet owners have described the appearance as a shiny piece of patent leather on the surface of the eye. While other sequestra have a browner, more bronzed appearance, they can cause the same level of inflammation. The plaque can often obstruct the central field of vision and make it difficult to see around. This corneal disease can occur in cats of all ages and breeds. The Persian breed have the highest level of frequency of occurrence. Although domestic breeds can have the disease, some other breeds at-risk include Siamese, Burmese, Himalayan.
The exact cause of feline sequestra is unknown. However, the development of a sequestra is often associated with corneal trauma, dry eye disease, abnormal eyelid conformation and/or Feline Herpes Virus infection. Since sequestra can be painful, if you notice your pet squinting, tearing, or elevating the third eyelid you should have them evaluated by a specialist.