A limbal or epibulbar melanoma is a deeply pigmented mass that arises from a pigmented shelf at the limbus, which is where the cornea (outer clear portion) and the sclera (white portion) meet. These tumors are typically benign but can be locally invasive. Most of these masses are single tumors that originate from the location in which they are visualized and do not spread from other areas of the body. They are usually smooth and have a dark brown to black pigment and are most often raised above the contour of the eye.
They are more commonly seen in German Shepherds, Golden Retrievers, and Labrador Retrievers but may be seen in any breed of dog and occasionally, in cats.
If the mass is small and not causing any structural changes within the eye, your ophthalmologist may recommend serial monitoring of the size of the mass. If your dog has a mass that is enlarging, then your ophthalmologist may recommend surgery. These masses may become large enough that intervention is not possible. Close monitoring with or without medication and/or surgical intervention may be recommended.
Surgical options may include:
A procedure to reduce the size of mass or remove the entire mass may be recommended. Adjunctive therapies include freezing procedures, laser procedures, and local irradiation therapy. Studies have shown these adjunctive therapies may reduce recurrence itself and/or the time to recurrence. Your ophthalmologist may place a graft over the tissue removed. This graft may be from adjacent tissue such as conjunctiva, sclera, third eyelid, or a synthetic material. For any of these procedures, after surgery, your pet may need eye drops, oral antibiotics, anti-inflammatories, and an Elizabethan collar for several days to weeks. The full healing time in which the surgery site becomes full strength again may take several weeks.
Enucleation may be recommended if the mass significantly affects the structure of the globe and/or is too large to remove surgically and/or if there are other concurrent conditions that influence a positive outcome such as glaucoma, cataract, or retinal detachment.
Typically, the prognosis is good for these tumors, as they are most often benign and locally invasive. The best option for your pet will be determined by discussion with your ophthalmologist.
