Immune-mediated keratitis in horses: 19 cases (1998-2004).

The research article analyses the clinical and histological findings of 19 horses suffering from immune-mediated keratitis (IMMK), which is a corneal disease, from 1998-2004. The study also investigates the effects of different treatments on these horses and their resulting outcomes.

Objective of the Research

• The purpose of the study is to examine the clinical and histologic details, treatment methods, and outcomes of horses suspected of having immune-mediated keratitis (IMMK).

Methodology

• The study is a retrospective analysis spanning from 1998 to 2004.
• It involves nineteen horses that presented with IMMK at the North Carolina State University Veterinary Hospital (NCSU-VTH).
• In their examination, the researchers looked at recorded signalments, the length of clinical signs, treatment prior to initial examination, ophthalmic abnormalities, diagnostic tools used, instituted therapy, and long-term vision of the horses.

Results

• The team discovered three distinct clinical groups based on the depth of the lesion in the cornea. These are superficial stromal, midstromal, and endothelial, consisting of 11, 6, and 5 eyes respectively.
• The ages of the horses varied from 5 to 19 years, with an average age of approximately 11.9 years.
• Eleven horses had shown clinical signs of the corneal disease for 12 months or more prior to their referral to NCSU-VTH.
• Each group presented differently – superficial stromal keratitis showed a superficial stromal cellular infiltrate and diffuse vascularization; midstromal keratitis showed a midstromal cellular infiltrate with mild, surrounding corneal edema and vascularization; endothelial disease showed endothelial cellular infiltrate with a diffuse corneal edema.
• Regardless of the type of IMMK, signs of uveitis or severe discomfort were not observed in any of the horses.

Conclusions

• Horses with superficial IMMK responded well to topical medical therapy, but the best results were achieved through surgical removal of the lesion.
• Midstromal keratitis was best treated with topical cyclosporine therapy.
• Endothelial disease proved the most difficult to treat.