Corneal Sequestrum

Nancy M. Bromberg, VMD, MS, DACVO

What is a Corneal Sequestrum?

Corneal sequestrum typically appears as a tan to dark brown-black area of corneal discoloration, frequently surrounded by inflammation and vascularization. Also known as corneal mummification or corneal black body, the sequestrum is due to an area of corneal necrosis. The sequestrum is frequently observed with refractory (chronic or slow-healing) corneal ulcers.  Contributing factors include breed predisposition (seen in Persian and Himalayan breeds more frequently), entropion (rolling in of the eyelid), and Feline Herpes Virus.  A sequestrum can also be caused by inappropriate use of grid keratotomy for chronic corneal ulcers. 

How is a Sequestrum Diagnosed?

The appearance of corneal pigmentation, especially concurrent with a chronic corneal ulcer or entropion, is diagnostic. The sequestrum frequently acts as a foreign body in the cornea, stimulating an inflammatory and vascular response. 

How is a Corneal Sequestrum treated?

Cats with corneal sequestrum should be evaluated for management by a board certified veterinary ophthalmologist. Several factors, including your pet’s general health, determine the treatment options for this condition. Some sequestrums are managed with medical therapies, but if significant discomfort to the pet is noted, surgical options are usually recommended. 

Corneal surgery requires an operating microscope and specialized microsurgical ophthalmic instruments. Corneal grafting with donor tissues are sometimes utilized during the surgical management of this condition.  Post operative healing usually involves medical therapy with supportive antibiotic and antiviral medications and proper protection of the surgical site is crucial for successful outcome.

What is the prognosis for a Corneal Sequestrum?

The majority of corneal sequestrums can be successfully managed with the guidance and training of an experienced board certified veterinary ophthalmologist. Early recognition of the condition is imperative and early treatment results in the most successful return to normal corneal anatomy and function. If not identified or left untreated, corneal sequestrum can lead to corneal infection and possible rupture of the globe and loss of the eye. 

Amanda Brown