Penetrating keratoplasty for treatment of recurrent squamous cell carcinoma of the cornea in a horse.

A 14-year-old horse that had recurrent squamous cell carcinoma in the cornea was treated using a combination of beta-radiation, hyperthermia, and an operation called penetrating keratoplasty that led to maintaining vision in the affected eye.

Understanding Squamous Cell Carcinoma and Treatment Strategies

• Squamous cell carcinoma is a type of cancer that impacts the squamous epithelial cells in the body. In this case, the carcinoma was located in the horse’s cornea and conjunctiva of the left eye.
• The initial treatment consisted of superficial keratectomy, a surgical procedure to remove the outer layer of the cornea, combined with beta-radiation, a type of radiotherapy that uses beta particles, and radiofrequency hyperthermia, a process that uses heat to kill or damage cancer cells.

Reoccurrence and Further Treatment

• Four months following the initial treatment, the tumor recurred at the edge of the location where the previous keratectomy was performed. At this point, penetrating keratoplasty was initiated.
• Penetrating keratoplasty is a full-thickness transplant of the cornea. This procedure was conducted with the intention to eradicate the tumor and maintain the horse’s vision in the eye. It’s an aggressive treatment generally used when other options have failed or aren’t suitable.

Results and Follow-Up

• Thirteen months after surgery, the horse’s eye remained visual, indicating that the keratoplasty had indeed helped in preserving the sight.
• Some minor complications like mild fibrosis (formation of fibrous tissue), and vascularization (formation of blood vessels) were observed in the area where the penetrating keratoplasty was conducted. However, this did not lead to any severe consequences and the horse was able to maintain its vision.