Treatment of advanced squamous cell carcinomas involving the equine cornea.

This is a study on the treatment of corneal squamous cell carcinomas in horses. The treatment involved surgical removal of the tumour and subsequent radiation and results showed that most of the treated horses remained tumor-free after long-term follow-up.

Study Overview

• The study focused on corneal squamous cell carcinomas (a type of cancer) diagnosed in 26 eyes of 25 horses. These cancers had surface areas larger than 2.0 cm, thus qualifying as advanced cases.
• Special attention was paid to the depth of the cancerous lesion into the corneal stroma (connective tissue in the eye) and if they involved the ocular adnexa (the tissues and structures surrounding the eye). These factors mainly determined the approach for surgical treatment.

Treatment Method

• Corneal cancers extending into the nearby palpebral conjunctiva, eyelid, or orbit (eye socket) were not considered suitable for complete excision (surgical removal).
• Tumours which involved only the cornea and bulbar conjunctiva (the transparent outer layer over the eye) were treated surgically via keratectomy (surgical removal of the cornea) and beta radiation.
• Initial treatment involved keratectomy followed by beta radiation on 24 eyes, while two eyes were treated through enucleation (removal of the eye).

Results and Follow-up

• Long-term follow-ups revealed that a significant number of keratectomy patients (20 out of 24) remained free of the tumour.
• However, one patient was lost to the follow-up, and three had their cancer recur.
• In the case of recurrences, additional treatments were carried out. One horse was successfully treated with a subsequent cure, one horse underwent enucleation, and one horse was euthanized.

Conclusion

• The surgical and radiation treatment methods applied in this study showed promising results in the management of corneal squamous cell carcinomas in horses. Despite a few recurrences, the majority of treated horses remained tumor-free after long-term follow-up.