engleski

ENUCLEATION WITH OPTIC NERVE LIGATION IN A HORSE – A CASE REPORT

Various diseases can cause a need for enucleation to be performed in a horse. Two preferred methods are transpalpebral and subconjunctival enucleation. As the optic nerve is very short in horses, its ligation is not advised due to the danger of vision impairment to the other eye. A 12 year-old Arabian stallion was presented for an eyelid tumour regrowth. A suspected sarcoid was surgically removed from the upper eyelid 8 years ago, using H-flap and local implantation of cisplatin beads. The owner noted significant tumour regrowth after 6 years. Tumour was extirpated as well as ¾ of the upper eyelid, leaving it strained dorsocaudally. Blepharoplasty with a sliding graft from the temporal region was performed and carboplatin chemotherapy was introduced. Histopathology showed a multifocal peripheral nerve sheath tumour of the eyelids. Since the horse was unable to move the upper eyelid, it developed keratoconjunctivitis sicca with secondary chronic corneal ulcers. Enucleation was planned. Three months later, transpalpebral enucleation of the right eye was performed under general anaesthesia. Care was taken not to damage the conjunctival sac and to avoid traction to the optic nerve. Precise dissection of periocular muscles was performed to enable optic nerve visualisation. A hemostat with a curved tip was placed on the optic nerve, then it was ligated using Polysorb 0 suture and transected. Tension-releasing incision was made ventral to the enucleation incision, prior to wound reconstruction. The horse recovered quickly with no vision loss to the other eye. No haemorrhage or haematoma formation was noted at the place of enucleation. Although usually not performed, optic nerve was ligated in this case, in order to prevent haemorrhage and minimize the possibility of infection so chemotherapy could be continued as planned. The present case shows that ligature placement on the optic nerve can be safe if it is performed carefully, avoiding traction to the optic nerve.

enucleation, horse, ligation

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