Corneal stromal sequestration and keratoconjunctivitis sicca in a horse.

The research reports on a specific case of a 19-year-old Shetland pony suffering from several eye diseases, including dry eye disorder, ulcerated inflammation of the cornea, and brown discoloration of the corneal stroma. Despite unable to identify the origin of these conditions, and due to financial and practical reasons, the owners opted for removal of the affected eye, which, when examined, showed loss of corneal epithelium and varying signs of inflammation and degeneration. The authors note a resemblance with a similar condition seen in cats.

Case Presentation and Conditions Identified

• The study begins with presenting the case of a 19-year-old Shetland pony who was experiencing discomfort and abnormal appearance in one eye.
• Upon ophthalmic examination, the horse was found to have Keratoconjunctivitis sicca (commonly known as dry eye syndrome), Ulcerative keratitis (a severe form of corneal inflammation that is often marked by corneal ulceration), and brown discoloration of the corneal stroma (innermost layer of the cornea).
• The exact cause of these conditions could not be determined in this case.

Remedial Action and Post-Examination Findings

• Due to practical and financial considerations, the owners decided to proceed with enucleation, which is the removal of the affected eye.
• After conducting a histopathological examination of the removed eye, it was discovered that there was significant loss of the corneal epithelium (the outermost layer of the eye).
• This layer was found to be situated above a region of corneal stroma that was displaying hypereosinophilic (a condition often related to allergies, skin disorders, etc.), degenerate, and necrotic (dead or dying) characteristics.
• Surrounding this area of corneal stromal sequestration (loss or blockage) was stromal vascularization (the growth of new blood vessels in the cornea) and severe inflammation, predominantly caused by polymorphonuclear cells (a type of white blood cell).

Comparison with Similar Conditions in Other Species

• The authors note that the clinical and histopathologic features of this equine case were remarkably similar to those observed in cases of Feline corneal stromal sequestration (an eye condition found in cats).