05 Jun Photodynamic Dye Therapy for the Treatment of Squamous Cell Carcinoma
By Karen Chapman, RVT
Bugs Magic Breese, a 13-yearold American Paint Horse mare, presented to the Texas A&M University Veterinary Medical Teaching Hospital on July 29, 2016, for evaluation of a recurring tumor on her lower left eyelid. The tumor had been resected previously and injected with cisplatin 45 days earlier.
Regrowth was noted (Figure 1) and Breese was referred for a second opinion. Breese was sedated with 10 mg detomidine administered IV to keep her comfortable and sedated during the procedure. An auriculopalpebral nerve block was performed using carbocaine to facilitate manipulation of the lid. A local block using carbocaine was used to desensitize the left lower eyelid. The tumor was resected using sharp dissection and the resultant wound bed was injected with 3.75 mg verteporfin (Visudyne; Novartis.) using a 5-mL syringe and a 25-gauge needle. Immediately following the dye infiltration, the area was exposed with a 690 nm wavelength, non-thermal laser red light source (LumaCare) for eight minutes. During this procedure, the globe was protected with a Styrofoam shield covered in duct tape.