Todayโs path rounds are on ๐๐๐ฅ๐ข๐ง๐ ๐๐จ๐ซ๐ง๐๐๐ฅ ๐ฌ๐๐ช๐ฎ๐๐ฌ๐ญ๐ซ๐! This was a request 
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐
๐๐ฅ๐ข๐ง๐ ๐๐จ๐ซ๐ง๐๐๐ฅ ๐ฌ๐๐ช๐ฎ๐๐ฌ๐ญ๐ซ๐ are an orange-brown area of ๐ง๐๐๐ซ๐จ๐ฌ๐ข๐ฌ (cell death) on the ๐๐จ๐ซ๐ง๐๐ (outer, clear layer of the eye). They can be ๐ฐ๐๐ฅ๐ฅ-๐๐๐ฆ๐๐ซ๐๐๐ญ๐๐ (well defined borders) or more โfuzzyโ looking. Typically only one eye is affected, however both eyes can be affected either at the same time or at different times.
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
This condition is seen in cats, particularly Persian and Himalayan cats.
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
The exact cause of these sequestra is unknown, but it seems likely that it is a ๐ฌ๐๐ช๐ฎ๐๐ฅ (condition arising from another condition) of corneal ulceration, which is basically a large hole in the cornea. This can be caused by chronic dry eye, viral diseases, or trauma.
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
These lesions are incredibly painful for the cat, and in some cases can even lead to ๐ ๐ฅ๐จ๐๐ ๐ซ๐ฎ๐ฉ๐ญ๐ฎ๐ซ๐ (rupture of the eyeball 
) if the lesion penetrates all the way through the cornea.
๐๐ก๐ฒ ๐ข๐ฌ ๐ข๐ญ ๐๐จ๐ฅ๐จ๐ฎ๐ซ๐๐ฎ๐ฅ?
The pigment that makes the lesion orangey to black are actually from ๐ฉ๐จ๐ซ๐ฉ๐ก๐ฒ๐ซ๐ข๐ง๐ฌ (organic compounds) that are found within the normal tear film that covers the eye. Because thereโs a defect in the corneal tissue, the porphyrins accumulate there, making an orange to black colour!
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
These lesions are pretty easy to see, and there isnโt much else that looks like them! To help confirm the diagnosis, the veterinarian can do a complete ophthalmic exam to assess the whole eye.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐?
These lesions are typically treated by ๐ค๐๐ซ๐๐ญ๐๐๐ญ๐จ๐ฆ๐ฒ, or removal of a layer of the cornea. After that, the hole in the cornea is usually patched with some sort of graft. Veterinarians have successfully used ๐๐จ๐ง๐ฃ๐ฎ๐ง๐๐ญ๐ข๐ฏ๐ (the tissue around the eye), porcine corneal tissue and even porcine intestine to make these grafts. Crazy!
๐๐ก๐จ๐ญ๐จ๐ฌ
1-5) Examples of corneal sequestra ranging from well-demarcated to more amorphous.
6-8) A series of photos showing a lesion (the bright green stuff is fluorescent dye used to identify ulcers), the lesion after receiving a graft from a donor eye, and finally the healed lesion!
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Laguna, F., Leiva, M., Costa, D., Lacerda, R., Gimenez, T.P. Corneal grafting for the treatment of feline corneal sequestrum: a retrospective study of 18 eyes (13 cats). Veterinary Ophthalmology (2015) 18, 4, 291-296.
Featherstone, H.J., Sansom, J. Feline corneal sequestra: a review of 64 cases (80 eyes) from 1993 to 2000. Veterinary Ophthalmology (2004) 7, 4, 213-227.
Andrew, S.E., Tou, S., Brooks, D.E. Corneoconjunctival transposition for the treatment of feline corneal sequestra: a retrospective study of 17 cases (1990-1998). Veterinary Ophthalmology (2001) 4, 2, 107-111.
Photo 1 from Andrew et al. Photo 2-4 from Featherstone et al.
Photos 5-8 from Laguna et al.
