Ocular Tumors- What’s Growing on my Pet’s Eye?

Ocular Tumors- What’s growing on my pet’s eye?

Nicole Scherrer, BA, DVM, DACVO

Cancerous masses that occur on or within the eye are known as ocular tumors. These tumors can occur on the surface of the eye (corneal tumors) or within the eye (intraocular tumors). Corneal tumors are commonly associated with UV light exposure and occur in lightly pigmented tissue. The most common corneal tumors diagnosed are squamous cell carcinoma (see photo) and hemangiosarcoma. To prevent these corneal tumors, UV light protection is recommended. Treatment of these corneal tumors varies but can include topical chemotherapy, cryotherapy (freezing), photodynamic therapy and surgical excision. The chance of recurrence depends on the treatment modality used and the type of tumor present.

Intraocular tumors can be incredibly difficult to treat. In some cases, intraocular tumors are primary, meaning they started within the eye. Secondary intraocular tumors started elsewhere in the animal (respiratory system, gastrointestinal system, etc.) and then spread through the blood to the eye. Complete resolution of a primary intraocular tumor can be achieved with eye removal (enucleation). Depending on the tumor type and size, globe sparing procedures, such as an iridectomy to treat iridal melanoma, may be effective as well. In cases of secondary intraocular tumors, more systemic treatments such as chemotherapy would be needed to treat the primary source of the tumor. A common cause of a secondary intraocular tumor is lymphoma.